Oddball engines and prototypes

[Frits Overmars]

No Frits - it's still "KISS" - (keep inventing silly shit) !:killingme........

[lohring]

I can't believe the things that have been tried to complicate a very simple engine. The NACA translated a German survey of some of the better attempts. See below. Of course DKW is the poster child for complicated two stroke designs. Today's tuned pipe engines only suffer from packaging issues. Otherwise, they can't be beat for high performance in a low cost and size package. Our 26 cc race engines cost less than $200 out of the box and can produce 4.5 hp stock with the right pipe. Modified they produce over 7 hp. How's that for your hot weedeater?

Lohring Miller

343896

[Pursang]

It's leaning to one side.

Does that make it a CATALIST ???? :innocent:

CATEGORICALLY !!! :laugh:

Cheers, Daryl.

[WilDun]

Yes,
There is no doubt that chambers are essential in two strokes today and Neil Hintz has more or less proved that with a bit of thought they can be packaged almost as neatly as your average four stroke exhaust, (Neil fiddles with fuel injection and rotary valve inlet timing as well). but chambers, ......... they are mainly all designed to give a better performance and to be most efficient at a certain point in the rev range and everywhere else there has to be compromise! - mostly carried out by mechanisms which "fiddle" with exhaust timing etc.

Chambers are all very good but they do not get us around the mixing of exhaust charge and fresh incoming charge containing oil (whatever we say, or think about that), it is still the reason that two strokes are disappearing fast! ie by legislation produced by ill advised politicians who have no clues about two strokes - their advisers not being familiar with the real 2 stroke facts either!

If we want better performance in the two strokes (for everyday use), then forced charging has to be better in this area (chambers after all are really supercharging using exhaust pulses) and if a properly designed supercharger is integral with the design of the engine (as opposed to a bolted on extra) what is the problem? - cost you say?
I say cheaper than the exotic 4 strokes we have today! - It's only the fear of breaking racing rules lodged in our brains that has prevented this happening!

Also there is the problem of the fresh charge mixing with the outgoing exhaust charge as it enters the cylinder ..... not to mention the uneven cooling effect of the fresh charge and the hot exhaust on the other side of the cylinder, producing distortion and consequently requiring greater clearances.

Again I believe Neil has an answer here - my feeling is, he hasn't had to time to carry on experiments with the opposed piston arrangement he started out with (apparently quite successful)!
I believe that layout, combined with some other innovations I have come up with - (don't want to mention them till I have filtered out some of my more ridiculous notions), which possibly could address some of the problems I mentioned above.

As always I could be wrong and I'm relying on you guys to advise me or point out any obvious blunders with my thinking! ....... but.... explain your thinking! - make it stick!

[Pursang]

I can't believe the things that have been tried to complicate a very simple engine. The NACA translated a German survey of some of the better attempts. See below. Of course DKW is the poster child for complicated two stroke designs. Today's tuned pipe engines only suffer from packaging issues. Otherwise, they can't be beat for high performance in a low cost and size package. Our 26 cc race engines cost less than $200 out of the box and can produce 4.5 hp stock with the right pipe. Modified they produce over 7 hp. How's that for your hot weedeater?

Lohring Miller

343896

That is an Amazing Document!:niceone:

Every issue clearly defined and described, back in 1934.
Including "the important effect of the exhaust pipes on the process of charging and scavenging"

Pretty much all that has happened since is improvement by refinements in details & metallurgy.
(With some outstanding results)

Cheers, Daryl.

[ceci]

If we want better performance in the two strokes (for everyday use), then forced charging has to be better in this area (chambers after all are really supercharging using exhaust pulses) and if a properly designed supercharger is integral with the design of the engine (as opposed to a bolted on extra) what is the problem? - cost you say?



I agree with you because life has shown me that what you say is true.
This year I made a mistake when acquiring a four-cylinder car with an atmospheric 1200cc. Months later a relative bought another but three-cylinder 900cc supercharged, this is a third more powerful than mine
343904

[Pursang]

OK Will, accepting the Challenge!
(and incorporating what has been know & achieved previously)
343905


Our 'Ideal' 2 stroke Could have a 4 stroke sump, separated from the combustion.

Supercharged fresh air scavenging with turbocharged boost for mid to upper RPM enhancement.

Exhaust by peripheral ports to achieve sufficient STA with maximum working stroke.

Scavenging through 4 poppet valves in the cylinder head, incorporating swirl and/or tumble to fully clear the cylinder.

Electronically controlled direct fuel injection monitoring Throttle position, Head, exhaust & ambient temperature, compression pressure rise, atmos pressure, density & humidity, gradient, braking, cycle "attitude", suspension compression/extension (magnitude and rate of change), front and rear wheel relative rotation, etc. etc.

Could be considered that we are converting the fabulous, but sadly retired, Detroit Diesel into a 'modern' spark ignition engine.:headbang:

Equivalent power to a 4 stroke at half the rpm (or around 2X at the same rpm)

Cheers, Daryl.

[WilDun]

DARYL & LOHRING
Yes I agree with what you say about the German commentary on two stroke engines - very futuristic thinking for the time.
Most of those predictions actually came to pass and worked well (for many years) - but, although their predictions regarding design were correct, they forgot to consider what people of later generations might be like! - they didn't consider the fickleness of fashionable people or that fashion might play any part at all! .......... but it has done and has just about sunk the two stroke! - sorry to sound like a pessimist, but really that's how it actually is today, not a negative rant about the future!

CECI,
My wife bought a 4 cylinder 1500 Mazda in preference to a turbocharged 3 cylinder turbo charged Suzuki Swift (and it was swift it accelerated like you wouldn't believe!) However we bought the Mazda which was well proven (old school really) but it's good for my wife!
Those tiny turbocharged engines are under too much stress, and it will be interesting to see which lasts longest without attention!

[ken seeber]

That is an Amazing Document!:niceone:

Every issue clearly defined and described, back in 1934.
Including "the important effect of the exhaust pipes on the process of charging and scavenging"

Cheers, Daryl.

What a good read...…..:yes:

[Pursang]

Might work out a little like this!:scratch:

343906

Easy conversion of an sl/xl air cooled honda single for a 2 or 4 valve proof of concept.
Regrind or cut & weld cam (all inlet) with engine speed (1:1) drive sprocket.

Converted Smog pump or similar for Supercharger driven by the cam, need to source a tiny Turbo.

EFI will probably take me far too long to conquer, maybe i would just use LPG, triggered at exhaust closing position.

Cheers, Daryl.

[ceci]

3 cylinder turbo charged Suzuki Swift (and it was swift it accelerated like you wouldn't believe!)



That is what makes me regret now that I know those engines.
If manufacturers were interested, they will look for where to find the solution to the 2S problem

[lohring]

When internal combustion engines were still at the forefront of mobile power plants, turbo and super charged two strokes were seriously considered. See the Rolls Royce Crecy and Napier Nomad. Since then two strokes still dominate large two stroke diesels and small, low cost power plants. The small IC power plant market is slowly being replaced by electric motors as batteries get smaller and lower cost. Two stroke simplicity and durability is what stands out in both these categories.

Lohring Miller

[WilDun]

When internal combustion engines were still at the forefront of mobile power plants, turbo and super charged two strokes were seriously considered. See the Rolls Royce Crecy and Napier Nomad. Since then two strokes still dominate large two stroke diesels and small, low cost power plants. The small IC power plant market is slowly being replaced by electric motors as batteries get smaller and lower cost. Two stroke simplicity and durability is what stands out in both these categories.

Lohring Miller

Good points Lohring! ..... and as you seem to be suggesting it could be used in the hybrid scene - probably as a constant speed generator engine. However, I don't think the piston ported two stroke supports long piston/cylinder life (but it sure worked well in the racing scene!).
All throughout the "high performance two stroke" era, piston ports were the norm with only the large diesel two strokes having poppet valves (the odd one having sleeve valves as in the RR Crecy) - the poppet valve has been maligned all through its very long existence, yet it has survived -

However, the racing scene did not represent the whole world's needs and the whole world's opinion is really what matters! - the two stroke's reputation has been tarnished through not focusing on exhaust emissions/perceived emissions and also by focusing on racing and forgetting the millions of commuter and tourist bikes and riders.

As a consequence of the (real and perceived) two stroke pollution in this area, the racing scene and increasingly the commuter scene is now dominated by four strokes and the racing machinery looks like the everyday motorcycle - this fits in well with the riders of commuter motorcycles - good for sales!

Before someone comes up with with the remark that the poppet valve is not good in the emission department either - yes that is also true but what a compromise it has been! - and after all, it only produces unseen pollution! :laugh:

BTW Daryl,
I still have to look at your post thoroughly - and I need to add that I'm no expert (it just looks like I think I am!!) but at least I'm very interested - even if engineering maths (except the simple high school and workshop stuff) escapes me! :rolleyes:

[Pursang]

OK, technically it's called a 'reverse' uni flow.

(Although it doesn't reverse and it still flows in one direction!)

Clever Idea, that has been formally tested years ago by Fuji Heavy Industries and Chiba University.

For those that don't know, Fuji is Subaru, which is 16% owned by Toyota, who has a 5% stake in Yamaha.

343920

So Will, your theory is proven! Here are a some of the most profitable motor companies in the world,
with proof of the superiority of this engine and they are sitting on their thumbs...:facepalm:


No cheers for this one, Daryl.

[WilDun]

EFI will probably take me far too long to conquer, maybe i would just use LPG, triggered at exhaust closing position.

Cheers, Daryl.

Daryl,
You don't need to conquer EFI for two strokes, it has already been conquered right here, by Neil - the average guy didn't really pay much attention, but big companies did - and when they take an interest, then it must be ok!



So Will, your theory is proven! Here are a some of the most profitable motor companies in the world,
with proof of the superiority of this engine and they are sitting on their thumbs...:facepalm:
Daryl.

As I have said many times, everything is governed by fashion, not engineering excellence! - but I'm sure they are thinking "lets just sit on it and then be the first to react when fashion changes"!

[Muciek]

Rotary slide Jawa enduro .

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[WilDun]

Rotary slide Jawa enduro .


Rotary slide Jawa enduro .

Very interesting - brilliant in fact!
It looks like it may have been around in the seventies, ie in the days when I was young - I can't understand how I could have missed it (but I obviously did!).
That layout does make it a very tidy arrangement -I wonder why it wasn't successful -

Probably better than a reed valve, but possibly not better than a rotary valve, ie from the point of view of it being more difficult to change the symmetry of the timing. There is some asymmetry there (judging by the relationship of the rod to the path of the sliding plate), but I feel that it would have been much more difficult to change the timing than with a rotary valve.

I dunno about the cost of manufacture either.

[WilDun]

Happy Christmas and New Year to all you guys - hope to be hearing from you in 2020.

[Pursang]

.
Seasons Greetings to you Will, and to Everybody else!:ride:

344002

Without attempting to change the world, or make any money or find a race class that it could compete in,
I think I will build one of these for a Honda XR Vinduro bike, (I have a rolling chassis in need of a motor).

Still working through the options on this one, but it seems to be a worthwhile exercise.

Advantages:

Over 'normal' 2 Stroke
Extended working stroke before EPO, (All blowdown, no transfer).
Crankcase lubrication separated from combustion. (including valve stems)
Full Scavenging Flush: No charge dilution. Clean, even, low speed running
Additional boost easily available. (plus Turbo-charging for high speed work)
Broad operating power band: (Exhaust tuning for gas extraction only)
Stratified combustion for light load efficiency, (late injection).
Uniform charge for high power, (early injection).
Combinations of charge & combustion processes also available.

Over 'normal' 4 Stroke
Power stroke per revolution, (twice the torque).
Cooler intake via head: less heat soak from ex valve & port.
No poppet valves in exhaust path.
Piston exposure to 'hot' gas reduced, (No exhaust stroke).
No cam drive & valve spring losses, (Pressure differential intake valves).

Disadvantages:
Supercharger required, Turbocharger optional, ( A Marketing +ve !):2thumbsup
Intake air warmed by blower.
Finding 'economical' (DIY) options for Direct FI.
Possible exhaust restriction around cam drive side of cylinder,
(Uneven heat load, particularly for air cooled engines).

Cheers, Daryl.:woohoo:

[ken seeber]

Dazza,
You've got me half interested for different reasons. :innocent:
Are you going to run a double lobe cam or run it at crank speed?
Obviously you'll need to have a full skirted piston adjacent to the exhaust port(s)
Enjoy the rain..

[Pursang]

Dazza,
You've got me half interested for different reasons. :innocent:
Are you going to run a double lobe cam or run it at crank speed?
Obviously you'll need to have a full skirted piston adjacent to the exhaust port(s)
Enjoy the rain..

Hi Ken,
Hopefully the rain put some fires out on the way through!

I first considered crank speed, then welding up some double lobes.
At this point, I am now planning to use un-cammed, differential pressure intake valves.
Like old school, atmospheric intakes, (or combustion resistant reeds).

Reasoning is this: I want the intakes to open as soon as the blow-down has reduced cylinder pressure to below blower boost pressure.
I want the intakes to close after the exhaust has closed and the cylinder is at full boost pressure.
No need for a camshaft to control this. The valve position will be managed by the pressure balance, not heavy springs.

Thanks for the tip re: the piston. Something to consider.
Short circuiting shouldn't cause a major problem with a reversion free exhaust (turbo could help this)
Might be important that the bottom of the skirt maintains a 'seal' to keep the crankcase separated from the exhaust??
Then again, this might provide PCV!
If necessary, could be a good opportunity to use a Flettner, bolt-in gudgeon, full circle, piston.

I am planning to use the redundant cam chain to drive the blower. (Aisin AMR300 looks to be the most affordable option)
At 300cc per rev, it's a little bit big for a 100/125 but I can drive with the cam sprocket at 2:1 and have plenty of scavenge volume or plenty of boost (or both).

Cheers, Daryl.

[Frits Overmars]

... combustion resistant reeds...Fireproof, pressureproof, detonationproof reeds that open at the slightest pressure differential, and with so little mass that they'll allow any rpm...
Did you try talking to Santa about it?

[lohring]

I just had a "discussion" about intake reeds on another forum. The highest duty reed intake valve I know about is in the combustion chamber of model pulse jet engines. I suspect that the pressures and temperatures in piston engines are considerably higher. The most serious limitation of poppet valves will be rpm. A sleeve valve should be able to run faster, but the flow pattern may not be ideal. Flettner on this forum has built a lot of different two strokes including uniflow designs. I'm not sure where he is on his sleeve valve engine.

Lohring Miller

[ceci]

Fireproof, pressureproof, detonationproof reeds that open at the slightest pressure differential, and with so little mass that they'll allow any rpm...
Did you try talking to Santa about it?



Those are the reasons why I switch to a metal spring hinge mechanism, it is more complicated in all aspects, but with more operational guarantees

[WilDun]

I just had a "discussion" about intake reeds on another forum. .............................The most serious limitation of poppet valves will be rpm. ........................
Lohring Miller

In the mid sixties there was a guy in England who converted a Triumph twin to a similar (poppet valve) system. - It did work of course, but he mustn't have taken it too seriously cos it seems to have disappeared from the scene!

Also in the sixties, there was a serious attempt by an Italian company (IMI Milan - from memory) who made one with a 4 valve head (poppet valve) for karts, but that also was in the sixties and couldn't compete with the rising performance of the 'conventional' two strokes.
The camshaft ran at half speed with 2 valves opening simultaneously - I think that they were probably the exhaust valves though and the crankcase was still used in the normal manner for the fresh charge - the half speed camshaft idea was no doubt to keep the poppet valves running at at sensible speed!

However, we are probably not thinking only competition engines here - it's really only everyday use of the two stroke that will guarantee its existence - competition engines possibly being derived from them of course, but perhaps its use in a generator role is most likely - as (I think) you believe as well Lohring?

These are all just my opinions and of course I could be wrong, but as I see it, it's the only way out for the two stroke at the moment ie using something like Daryl's arrangement.
As a good affordable lightweight powerplant the two stroke is an excellent choice, so long as we don't clutter it with "extras" but we do have to take the slightest hint of pollution seriously (ie as it is seen by the general public and dumb politicians ).

[Pursang]

Fireproof, pressureproof, detonationproof reeds that open at the slightest pressure differential, and with so little mass that they'll allow any rpm...
Did you try talking to Santa about it?

Santa said, "Be a good little Poppet..... 'cos until you get yourself off the Naughty List, you're getting S..t!"::nono:

Cheers, Daryl

[WilDun]

Santa said, "Be a good little Poppet..... 'cos until you get yourself off the Naughty List, you're getting S..t!"::nono:

Cheers, Daryl

At least you got a civil reply! - any time I mention poppets to the 2T boys , all I get is a terse F**K OFF NODDY :(

(BTW, even Santa has gone 4T as well)

[Pursang]

.
Preliminary calculations on the cam-less valves suggest that 28mm diam. Ti valves of 24g with 50kpa of boost will produce 7mm of lift in 90 deg. up to 2500rpm.....IF....
Blowdown can reduce cylinder pressure to Zero or below. (Absolutely Zero)..and the differential be maintained during intake.:pinch:
(About the same sort of revs where they stopped using atmospheric intakes, around 100 years ago) :o

The Camshaft LIVES!..:bash:

Cheers, Daryl.

[Pursang]

.
Direct Injection is off My table at present.

Lack of small compact pumps to provide 200bar is an issue.

The best that Honda can do is this Patent:344011

Sticking, what looks like, an automotive sized, Bosch DI pump on top of an engine. :facepalm:

Boldly developing New and Exciting Advanced Technology for (maybe sometime in) the Future!!!
Or at least to stop anyone else from trying! (A Honda uniflow 2-Stroke patent pdf is attached)

Cheers, Daryl

[Pursang]

F**K OFF NODDY :(

Fortunately, this is the Oddball engine thread!

The Noddy bike lasted as long as the BSA Bantam! ;)

cheers, Daryl

[husaberg]

Fortunately, this is the Oddball engine thread!

The Noddy bike lasted as long as the BSA Bantam! ;)

cheers, Daryl

I was reading about rhe LE velo last night it turns out they weree called a noddy bike as the rider was meant to salute other police officers when mounted it turned out due to the hand-shift on the velo most of the time he could not so they allowed then to nod which started of the nickman noddy bike. sounded plausable.
the orifial carb had something like 7 seperate jets in it.
from memory it was 100 pound dearer then a bantam and about 100lb heavier.

[WilDun]

I was reading about rhe LE velo last night it turns out they weree called a noddy bike as the rider was meant to salute other police officers when mounted it turned out due to the hand-shift on the velo most of the time he could not so they allowed then to nod which started of the nickman noddy bike. sounded plausable.
the orifial carb had something like 7 seperate jets in it.
from memory it was 100 pound dearer then a bantam and about 100lb heavier.

The LE Velocette was a unique bike but not exactly a ball of fire - good for pottering about on but as far as I was concerned there was not a racing part in it, (except the front forks, often used in specials) - the good old Bantams and Tiger Cubs could be turned into great little speed machines.

Velocette also made a scooter called the Viceroy which had a 250cc two stroke boxer twin engine mounted up front, just behind the front wheel - looked like it might be good, but by that time Velocette were on the slippery slope ....

Triumph also made a scooter called the Tigress which used the four stroke 250cc parallel twin engine originally designed for the Sunbeam motorcycle which was aimed (unsuccessfully) at the American market. - The Tigress was actually a good scooter, it had unusual front forks (resembling conventional forks with twin legs) but which were turned through 90 deg. making it a unique one sided setup and easy to remove the front wheel - It actually handled better than many motorcycles of the day! (I owned one for a short time).

Might try and dig up some info on all these machines, unless Husa beats me to it of course :whistle::innocent:........ Husa - you there?

[husaberg]

The LE Velocette was a unique bike but not exactly a ball of fire - good for pottering about on but as far as I was concerned there was not a racing part in it, (except the front forks, often used in specials) - the good old Bantams and Tiger Cubs could be turned into great little speed machines.

Velocette also made a scooter called the Viceroy which had a 250cc two stroke boxer twin engine - looked like it might be good, but by that time Velocette were on the slippery slope ....

Triumph also made a scooter called the Tigress which used the four stroke 250cc parallel twin engine originally designed for the Sunbeam motorcycle which was aimed (unsuccessfully) at the American market. - The Tigress was actually a good scooter, it had unusual front forks (resembling conventional forks with twin legs) but which were turned through 90 deg. making it a unique one sided setup and easy to remove the front wheel - It actually handled better than many motorcycles of the day! (I owned one for a short time).

Might try and dig up some info on all these machines, unless Husa beats me to it of course :whistle::innocent:........ Husa - you there?

I think the Viceroy was a little smaller 200cc? nope 250cc
appears to be 2t
344016344017344018
http://velobanjogent.blogspot.com/2008/04/from-viceroy-scooter-to-small.html
there was also a convention bike called the Valiant that used what appeared to be a OHV LE engine.
344019344020
There was a guy in NZ that put a tigress into a Cub or 3TA chassis it looked rather nice.
the viceroy and the later Le had a conventional box from what i read the hand shift on the LE was meant to make it easier for a car driver to learn to shift (i doubt it was)

[WilDun]

https://www.dailymotion.com/video/x2u3jlz
Sunbeam S7
344022344021344023

__________________________________________________ __________________________________________________ ______


https://www.pressreader.com/australia/old-bike-australasia/20190101/281625306417441
The 250cc Triumph Tigress (which used the engine from the Sunbeam S7 above) was often criticised, but was really a good design (if it had been properly de-bugged) - unfortunately it just arrived at the wrong time!
The BSA/Sunbeam version came with the BSA Bantam 175 engine installed in it.
344024

https://books.google.co.nz/books?id=U_taRN9B4HIC&pg=PA69&lpg=PA69&dq=triumph+tigress+front+forks&source=bl&ots=TCZ7LVBqQb&sig=ACfU3U2zSa7ri-AkyPl78ftIueB1AhazpA&hl=en&sa=X&ved=2ahUKEwjwiYym2dbmAhW47HMBHcYOCd84FBDoATAAegQIC RAB#v=onepage&q=triumph%20tigress%20front%20forks&f=false

[WilDun]

Husa, I see you are about to hit 9999 posts - do try to make it on this thread! !

[ken seeber]

Husa, I see you are about to hit 9999 posts - do try to make it on this thread! !

Go Husa....the 10K Oddball...:laugh:

[Pursang]

.
Oddballs are very welcome here!

344027

The Viceroy engine was well conceived with lots of positive features, it deserved further development.

Case Reed induction was bleeding edge in the 70/80's let alone 1950/60's.

A water-cooled, racing version would have been So easy for Velocette. Beat the TZ by 10 years.


Husa, does 9999 mean you go back to Zero?

Cheers, Daryl.

[husaberg]

Triumph 2t i never seen.
344028344029344030344031344032344033

[WilDun]

Interesting stuff - never before heard of that engine, - must say the Tiger cub looked a lot better with its original engine!- trouble is, the Poms (or at least the Pommie big wigs ) just flatly refused to believe or understand that they could be beaten!

They became desperate and tried anything but didn't have the cash to develop anything properly - All Britain's cash went to rebuild Japan and Germany ( ie in paying back the Americans for the stuff they got during the war (lend lease) and America immediately investing it in those two countries - the Russians and the British both had a hard time after the war, except that Russia had more resources to help them recover! - that's how I see it anyway!

Velocette I do believe had a potential winner there in the Viceory, but they folded like all the others so it never had a chance. I remember trying to buy a barrel and piston when the Viceroy was (supposedly) in production - I tried to buy them as new spares but just got a letter to say that they were unable to supply the spares I required for my scooter! - ( I had thought it would make a good starting point for a 125 racing engine). - but that's what things were like in those days!


ADDITION: - I was only interested in the engine of course, but was just having a browse on the Viceroy and came to the conclusion that they are UGLY looking beasts!! - funny thing is though, the Black ones actually look not too bad! .......Velocette not too hot on styling I must say. so, 9 out of 10 for the engine, ..... 2 out of 10 for styling!

[Pursang]

The 2 Stroke Triumph article loses some credibility with the 'chore horse' reference.:no:
The Chore Horse was a 4 Stroke side valve, like a Briggs & Stratton, with a canted cylinder,
(probably to side step a patent).
Re: the 1967? Triumph Two Stroke. Why? Why? Why?, for God's sake, didn't they just update the Ariel Arrow engine.:doh:
Twin Carbs, Alloy cylinders, 5 speed box, then rename it Triumph (or BSA, AJS, Norton, etc, etc, etc.) And put it in a conventional frame. Development cost = $SFA
That's what a 1959 Yamaha YDS-1 looked like, FFS! (and pretty much, every one, ever since).:first:

(Miss)Management with too many Ego's, brand loyalties (and dis-loyalties) and Head in Arse, Bulldog, pigheadedness, I guess.:oi-grr:

It's pretty obvious how the Japs left them behind.:buggerd:

Three Rousing Cheers, for (what was) the British Motorcycle Industry.:drinkup: Daryl

[Pursang]

Re: the 1967? Triumph Two Stroke. Why? Why? Why?, for God's sake, didn't they just update the Ariel Arrow engine.
Twin Carbs, Alloy cylinders, 5 speed box, then rename it Triumph (or BSA, AJS, Norton, etc, etc, etc.) And put it in a conventional frame. Development cost = $SFA
That's what a 1959 Yamaha YDS-1 looked like, FFS! (and pretty much, every one, ever since).l

344035344037

344039344036

Cheers, Daryl.

[WilDun]

Daryl,
Don't get me going on the Ariel Arrow - I actually had 3 of those (or was it 3.75? ) with some grand ideas about racing one - then along came the Suzuki T20 and that was the end of that idea!

As for the Arrow frame (body) it was a brilliant handling bike - maybe a little heavy but it could have been lightened with an alloy body - the wheels were too small - the brakes too weak - but I did like the trailing link front suspension.
I believe that just a few relatively minor improvements would have made it king of the road! but........... it's the same sad old story, it's all fashion driven and if it's not in fashion it won't thrive, so it disappeared, a prime example of what could have been - in hindsight it's so much easier to see what should have been done I guess!
The design was a brilliant concept by the designer, (Val Page) but was not properly developed and to be honest, I think it was destroyed by Ariel when they decided to make it on the cheap, pandering to the dickheads who were easily parted from the little bit of cash they happened to have! (mainly through the new post war hire purchase).:rolleyes:

Daryl - in my opinion the engine/gearbox would have needed a major major redesign - it did have one or two interesting, unique features which deviated from the norm, but again these were not developed properly so they died - somewhere around 15-16 BHP didn't compare favourably with the T20 SuzUki at around 28 BHP!

So with its chain primary, old school gearbox and its iron air cooled barrels with tiny transfer passages, also the two crankshaft halves being tapered and keyed together (cheap as) - their misalignment often caused inaccurate ignition timing, I don't think it could have survived the Japanese onslaught.

Anyway, I loved both the Arrow and the Tigress - and still do, despite their failings!

PS, the T20 may have been fast, but it handled like ........ well, like shit really! - the Arrow on the other hand felt like it was on rails!

[husaberg]

Tis a plug.
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[Pursang]

Tis a plug.
344040344041344042344043

'Tis a plug for the fact you're on 9997!:bleh:

Lot of work there to create 6 whisker points! But I'm sure it seemed like a good idea at the time.

Fortunately you could disassemble it to clean out the carbon & oil fouling.

I had a two piece plug on my first Villiers, but it didn't have an propeller!

Cheers, Daryl

[ken seeber]

I remember when I was a kid before getting pimples, we used to have a Wolseley 6/80, which also happened to have twin SUs. Anyway I remember my old man used to have spare KLG detachable spark plugs in a tobacco tin. Take them apart and give them a clean. Not to sure if heat ranges were around then.

344045

[Grumph]

I remember when I was a kid before getting pimples, we used to have a Wolseley 6/80, which also happened to have twin SUs. Anyway I remember my old man used to have spare KLG detachable spark plugs in a tobacco tin. Take them apart and give them a clean. Not to sure if heat ranges were around then.

344045

Ha - I learned to drive in my old man's 6/80. Three on the tree and a lot of shoulder muscle needed at low speeds. FE80 KLG rings a distant bell....
He was a fan of prewar Wolseleys. He'd had, tuned and raced, a prewar Wolseley sports, then loaned the engine to Hec Green who won the second Lady Wigram Trophy race with it in the RA Special...He thought he'd like to try the postwar offering so bought the 6/80. Hated it. Replaced it with a Mk7 Jag which had one bad bigend...He found a set of Vandervell lead bronze shells brought out for Archie Scott Brown and still on the shelf. Put them in and told us that it would see him out and any trouble after that was our problem....Sure enough it started knocking about 6 months after he died....

[husaberg]

Ha - I learned to drive in my old man's 6/80. Three on the tree and a lot of shoulder muscle needed at low speeds. FE80 KLG rings a distant bell....
He was a fan of prewar Wolseleys. He'd had, tuned and raced, a prewar Wolseley sports, then loaned the engine to Hec Green who won the second Lady Wigram Trophy race with it in the RA Special...He thought he'd like to try the postwar offering so bought the 6/80. Hated it. Replaced it with a Mk7 Jag which had one bad bigend...He found a set of Vandervell lead bronze shells brought out for Archie Scott Brown and still on the shelf. Put them in and told us that it would see him out and any trouble after that was our problem....Sure enough it started knocking about 6 months after he died....

Good to see you are still kicking i bet all those xmas deliveries kept you busy , I am over CHCH on Wednesday to pick up a bike for jnr i might call in if you are going to be around Greg?
I have a tank template for you retired mate.

[WilDun]

Good to see you are still kicking........

likewise Greg! - thought you and Neil had gone forever - but happy 2020 to all you guys!

[Grumph]

Still around and kicking. I watch but seldom sign in as when I do I'm watching frozen screens for too long. Middle of 2020 we should be updating our internet so watch out...
Yes, home weds. Any tank you might want done is in a queue behind my requirements.....He shows no sign of starting production at this point.

Actually the 6/80 is a good example of an oddball engine. It and the very rare twincam MGA are I think the only OHC engines BMC marketed in the 50's.
The Morris version in the same shell had the 6 derived from the truck engine - and was a better engine.
The later big Wolseleys all had pushrod engines - and went much better.
I have no idea why they ever did the OHC unless there was internal pressure from the ex Wolseley staff still in high places.

[ken seeber]

Daryl,
This is a pic of a piston we (Orbital) made around 1998 for Lotus for a wet sumped, externally scavenged engine. Note the oil scraper position, bit of a heavy lump.

344060

Sorry about the smoke fellas

344061

[WilDun]

Daryl,
This is a pic of a piston we (Orbital) made around 1998 for Lotus for a wet sumped, externally scavenged engine. Note the oil scraper position, bit of a heavy lump.

Sorry about the smoke fellas


Yes Ken, got to get rid of those two strokes from Aus. :msn-wink:

I came to NZ in 1966 and remember distinctly being in Raglan (west coast north island) - as opposed to south island -(Husa territory) - the sky was brown with a very smoky smell and red sunsets!
That was all from the forest fires in Tasmania (not such recent news!).

[husaberg]

Yes Ken, got to get rid of those two strokes from Aus. :msn-wink:

I came to NZ in 1966 and remember distinctly being in Raglan (west coast north island) - as opposed to south island -(Husa territory) - the sky was brown with a very smoky smell and red sunsets!
That was all from the forest fires in Tasmania (not such recent news!).

It blocked out the entire sun this morning, my son asked me if it was the moon at CHCH.
We have had your dust occasionally as well as pollen.
A snake landed with a plane in Queenstown the other day.
edit even now its still blocking out the sun.

[Michael Moore]

Ken, Laverda 125/150 4T singles used those oil rings below the wrist pin, and every one I took apart had the piston skirt broken off at that ring groove. Of course, that could be down to those motors being worn out and/or abused before I got them, but it seemed to indicate a trend.

cheers,
Michael

[WilDun]

It blocked out the entire sun this morning, ...........

And to you Aussies, we don't want any of your bulldust either! ok? :msn-wink:

[ken seeber]

Michael,
I’m surprised why they (Laverda) bothered with the oil ring down so low. The reason why the Lotus piston and also Orbital’s 3 cyl (1 litre) and 6 cyl 2 litre) externally scavenged engines, was that, being 2 strokes, that we didn’t want to uncover the exhaust port with the skirt nor have the oil scraper passing over the port, for obvious reasons. However for a 4 stroke, keeping the scraper cup high, means that the piston skirt has access to good lubrication conditions = longevity.
In saying that though, I do seem to remember (visions) of some old diesel piston (probably pommy) that had the scraper at the bottom. Couldn’t see it with a quick Google though.

Will,
Ozzies don’t bulldust, just bullshit.

[WilDun]

Will,
Ozzies don’t bulldust, just bullshit.

Bulldust (to those who may not understand) is just airborne bullshit! :laugh:

[Michael Moore]

Ken, maybe since it was a near-horizontal cylinder Laverda thought they needed extra help since the oil wouldn't just fall into the sump? But then the late 1960s Guzzi V7 also had an extra scraper ring

From a Mick Walker book: "The following year, 1968, saw the 700cc V7 continue, but now with a new starter motor and the carburettors changed to square slide ... A new type of piston was used – although there were still four rings, the oil scraper was moved to join the other three above the gudgeon pin and the skirt was relieved to give an almost semi-slipper type appearance."

Here's a link to a photo of one of the Guzzi pistons:

344069

cheers,
Michael

[190mech]

Rings at the skirt bottom is quite common in aircraft engines,the Continental O-200 has the oil control ring at the bottom of the skirt;
http://www.aircraftspecialties.aero/piston-aec530348/
The bigger Continental 470,520,&550 engines have the oil control ring above the piston pin,but have an oil scraper ring in the skirt which
scrape 'up' to keep an oil film between it and the control ring;
http://www.aircraftspecialties.aero/piston-set-balanced-654850bp/
..All these designs are direct drive,low RPM(2850 max) engines of old design,but very reliable..

[WilDun]

Rings at the skirt bottom is quite common in aircraft engines,the Continental O-200 has the oil control ring at the bottom of the skirt;................................All these designs are direct drive,low RPM(2850 max) engines of old design,but very reliable..

Do those aircraft engines need the extra rings for inverted flight?
I once (illegally) checked out a Hiller crop spraying helicopter parked in a field on our neighbour's farm for the night and being a teenager with a couple of friends, started it up too! - (I also had some lunatic thoughts of taking off as well- but commonsense prevailed!) :facepalm:
I did however notice that it had a flat 6 Lycoming engine mounted with its crankshaft sitting vertically - I guess this would be a case where an extra oil scraper would be necessary?
I'm also supposing they had seperate oil tanks with scavenge pumps in the crankcase?

[Pursang]

Bulldust (to those who may not understand) is just airborne bullshit! :laugh:

Damn Fine Bullshit!:yes:

Cheers, Daryl.

[WilDun]

Damn Fine Bullshit!:yes:

Cheers, Daryl.

Seriously though, it was brought home to us in Auckland (NZ) last Sunday - when we looked out at 3 pm it was like looking at twilight through yellow tinted sunglasses! - sure brought it home to us just what it might be like in Australia ........ to you overseas guys, (just to get it in perspective), - Australia is at least a 3 hour plane trip across the Tasman sea! . ......... no bullshit!

[WilDun]

Daryl, I reckon I've seen something like this handy bike stand before - can't remember where!

[Pursang]

Daryl, I reckon I've seen something like this before - can't remember where!

Strong Meds will do that!....but you don't want to spend too much time hanging around here!

344156

These have electric lift & tilt. Rated for hundreds of kg's.

Bargain priced, when they 'date out' and need to be disposed of. ;)

Don't google 'motorcycle lift / workbench' etc.


Cheers, Daryl.

[WilDun]

Talking about prototypes, what do you think F1 and Moto GP are brewing up on a two stroke platform?

Back in the sixties when all those wonderful new ideas kept pouring out from the manufacturers - the lead up to the 1962 (first) 50cc IOM TT was on and very exciting, - every man and his dog wanted to enter his 'specially tuned fast 50' - some even claiming 70 mph! - it was completely unknown what the manufacturers were going to come out with!

In the actual event it turned out that all the home brewed fifties were not quite up to competing with the works machinery and Honda and Suzuki probably did a better average speed than the the others top speed! - i think they were reaching top speeds of around 115 mph! - i seem to remember the Kreidler was the best of the road bike based entries (I think it had a compound gearbox (4X3, giving it 12 speeds) but I'm sure Frits knows more..

So I'm hoping we get the same sort of surprises when (if) these new two strokes eventually do become reality!

[Frits Overmars]

... i seem to remember the Kreidler was the best of the road bike based entries (I think it had a compound gearbox (4X3, giving it 12 speeds) but I'm sure Frits knows more..Those 12-speed Kreidlers had little in common with their road-going cousins: rotary inlet discs on both sides of the engine and indeed twelve speeds. Initially 4-foot x 3-hand like you say, but downshifting without losing count was a nightmare for the riders, so the later versions had 6-foot x 2-hand. I posted pictures of both versions here some time ago: look for Kreidler 12V. Or you can take a look at the FOS Google drive: https://drive.google.com/drive/folders/18l2ShH-MzrnTO0uEk9rNTk89_KgwgWof

[WilDun]

Those 12-speed Kreidlers had little in common with their road-going cousins: rotary inlet discs on both sides of the engine and indeed twelve speeds. Initially 4-foot x 3-hand like you say, but downshifting without losing count was a nightmare for the riders, so the later versions had 6-foot x 2-hand. I posted pictures of both versions here some time ago: look for Kreidler 12V. Or you can take a look a the FOS Google drive: https://drive.google.com/drive/folders/18l2ShH-MzrnTO0uEk9rNTk89_KgwgWof

Thanks Frits for sharing your treasure trove!! ....... (you're right up there with Husa!!) :msn-wink:

I have only just started to go through all the stuff I thought I would never see again - I guess we were lucky in that we grew up through the post war explosion of new ideas, some ridiculous, some very successful - but all very exciting stuff!
Kreidler at that time (until Jamathi came along) certainly kept Europe afloat through the Japanese explosion! but unfortunately, it was getting to the stage where only the rich manufacturers were able to continue with their (ridiculous) innovation and the ordinary guys couldn't compete (again except Jamathi).

Also road bikes weren't ever likely to be able to follow suit in their designs and much as I hate rules, this is one case where rules did work extremely well, that is when fifties and 125 classes became restricted to single cylinder and six speed - instead of 14 speeds and 3 cylinder fifties (as Suzuki were trying when it all changed)! that's when they actually started (forced ) to look for more torque and less revs! instead of the crazy stuff of the late sixties!

The (short lived) Bridgestone fifties (yes, the Bridgestone tyre company) were right in the thick of it as well! - ie until forced to concentrate on tyres by the other Japanese companies - or so I'm told! ..... Tohatsu were in the mix as well!

Oh no! - I'm off again! - and just as I thought I was winding down! :facepalm:

As I said, i've only just started to look through all your stuff - thanks again.

[Flettner]

Still here, just waiting at the dentist.
I guess I might have some stuff to put up soon.

[WilDun]

Still here, just waiting at the dentist.
I guess I might have some stuff to put up soon.

That sounds good!
We have had some stuff from Frits pop up - lots of stuff I hadn't seen for years (much worth revising).
I thought Husa had just about everything in his (missing??- confiscated?) archives. - still we can maybe look to the future now, seeing that F1 and Moto GP are actually contemplating using two strokes would you believe!

However, the whole automotive market may then start looking in the direction of using new clean two strokes, ie if they can break into the mindsets of the people who matter ....... customers! - and that will take some proper marketing expertise I guess!

Ironically, I (grudgingly) have to admit that I actually admire Harley Davidson for doing just that, by still managing to sell early post war designs ..............70 years later!!

[el chupacabra]

I thought this might be the place to post seeing as it’s and oddball idea.

So hearing about how someone somewhere has been discussing the possibility of using a two stroke engine in F1 at some stage in the future, I remembered Ferrari had made a two stroke prototype engine at one stage. I noticed this engine had an OHV for the exhaust.
So I thought to myself what would be the flaws in having an OHV two stroke but placing 4 small inlet valves in the head and running the exhaust ports down the bottom like in a normal two stroke with conventional expansion chambers. The inlet valves would open with standard durations when the transfer ports would normally open.

I can see the pros being:
-more exhaust area
-wet sump for higher rpm
-better for emissions with no oil in the fuel
-less wear
-getting the benefit of the expansion chambers
-cooling the bottom of the piston with oil sprayers

Cons being:
-more parts and cost
-most likely everything escaping straight out of the exhaust

So I would appreciate if someone could poke some more holes in this idea for me.

[lohring]

Rpm would be restricted due to poppet valve limitations. A conventional disk valve engine would work well in a hybrid drive with an exhaust turbocharger. An electric drive turbo could allow a wet crankcase, but you would loose the natural piston cooling of a crankcase scavenged engine. That's not too different from current systems. Even more power could come from an opposed piston, FOS, or sleeve valve engine. Piston cooling could come from crankcase oil spray into the piston.

Lohring Miller

[husaberg]

Still here, just waiting at the dentist.
I guess I might have some stuff to put up soon.

Be sure to fill us in...

[WilDun]

I thought this might be the place to post seeing as it’s and oddball idea.

So hearing about how someone somewhere has been discussing the possibility of using a two stroke engine in F1 at some stage in the future, I remembered Ferrari had made a two stroke prototype engine at one stage. I noticed this engine had an OHV for the exhaust.
So I thought to myself what would be the flaws in having an OHV two stroke but placing 4 small inlet valves in the head and running the exhaust ports down the bottom like in a normal two stroke with conventional expansion chambers. The inlet valves would open with standard durations when the transfer ports would normally open.

I can see the pros being:
-more exhaust area
-wet sump for higher rpm
-better for emissions with no oil in the fuel
-less wear
-getting the benefit of the expansion chambers
-cooling the bottom of the piston with oil sprayers

Cons being:
-more parts and cost
-most likely everything escaping straight out of the exhaust

So I would appreciate if someone could poke some more holes in this idea for me.

Can we call you EC?

Like you i would appreciate hearing exactly what others think of some of my more "airy fairy theories" - say what you think, I can take it - better than having people muttering in the background!

Yes I do agree that poppet valves would probably not be up to the job in a competition engine, but they might survive in an engine for more mundane jobs around the streets. Also ohv type poppets for the inlet would of course need a blower if the crankase is to be wet sump style.
Personally I don't believe that there is a future for expansion chambers in an ordinary road/street machine as basically they are used to great effect (read necessary) in a competition machine but in a relatively restricted rev range and to make them work perfectly all over the rev range is a very different thing and will require different remedies to the point that it is not worthwhile!

The market for the two stroke (in my opinion) lies with the general public acceptance - that will be governed by the sound and the cleanliness of the exhaust, also how it needs to be marketed and this is the only way I can see as a means to get back again - all despite the fact that it has been proven to have the possibility of simplicity, compactness and a power to weight ratio second to none, so as I see it, it has no hope of rejoining the world wide market until it's exhaust issues have been completely resolved - there is no longer any sense in encouraging the use of the present day Schneurle system of charging the cylinder or using the exhaust in lieu of a (necessary) supercharger in the form of an expansion chamber. The banning of superchargers was not sensible - it was introduced by those who knew better ie those at the top, who also saw fit to dispose of the two stroke in racing altogether, maybe not worded in that way, but it effectively made it impossible for the two stroke to continue racing!

Hopefully the engines they are beginning to look at for GP racing will be bring the two stroke back from the brink and have it accepted again. I believe that it can be, but it needs a complete redesign - the opposed piston layout could offer many benefits, one of which includes keeping the fresh charge away from the spent charge - this will reduce distortion and hence will help in the ability of using smaller clearances - that, along with not using an expansion chamber exhaust where a lot of charge mixing is bound to be taking place, will make the filling of the cylinder by a supercharger a more sensible approach.
I believe we have to look at the overall world wide use of the two stroke and take note of why there is such opposition to it

i also would be interested in using a constant speed piston engine (two stroke of course) running at its most efficient speed driving an electric motor through a generator where - only a simple but efficient engine would be required, that instead of trying various remedies to make it operate perfectly right throughout the rev range!
Fuel injection and HCCI has to be looked into as well and both will surely? be looked into.

As an afterthought I have decided to mention the Commer TS3 ( also Foden trucks,) - the TS3 was a 3 cylinder, 6 piston (opposed piston layout) diesel which is said to be the most efficient two stroke engine ever produced! - it was used for many years in trucks and fishing boats - was exceptionally smooth running and very economical.
However they (Rootes Group) were bought out by Chrysler who immediately scrapped it, to remove all opposition to their Cummins four stroke trucks. ....... sad saga of the two stroke - always the loser??

[el chupacabra]

Yeah EC works.

Obviously the idea I had wasn’t actually thought out using any calculations or anything just picturing what I think I know in my head (which is probably not as much as I think), it would be neat though to have it super charged and direct injected. Surely you would be able to keep the transfers open after the exhaust closes if you’re supercharging/turbocharging. Variable valve timing would be easier to achieve at least for intake valves like a VTEC set up or how Suzuki changes the cam timing with centrifugal force. You could also have a power valve on the exhaust to spread the power. Also cranks could be one piece and all the bearings could be plain bearings.

After looking at that opposed piston truck motor and watching some videos I couldn’t help but admire the simplicity and ‘terrible sound’. It’s a shame that it was scrapped.

If you got the supercharger to whine loud enough the exhaust noise wouldn’t be a problem for the general population, assuming everyone loves the sound of a whining supercharger and assuming it’s belt driven. But jokes aside couldn’t It be muffled down like any other modern car which is virtually silent. Or even having it coupled with a plug in hybrid set up would work as it wouldn’t be started for most daily driving tasks. Therefore not offending as many eardrums.


I can’t imagine they would resort to efficient stationary engines for racing, unless they give CVT the go ahead in F1. It would probably sound terrible though, cars droning around for an hour or so racing in a procession to the flag as they will all be restricted by how much fuel they can waste.

[lohring]

Eco motors (now gone) had a two stroke that fills a lot of what you are thinking about. However, I doubt that any IC engines will survive except in the largest sizes. The biggest engines in ships are turbocharged two strokes.

Lohring Miller

344501

[WilDun]

Eco motors (now gone) had a two stroke that fills a lot of what you are thinking about. However, I doubt that any IC engines will survive except in the largest sizes. The biggest engines in ships are turbocharged two strokes.

Lohring Miller

You may be right Lohring and I know that you are in favour of pure electric - I would like that too! ..... but it is highly dependent on infrastructure - people in less developed countries want individual transport and these countries are not well known for good infrastructure!
I think the hybrid is still viable, at least for the moment.

Motors (used in pure electric and hybrids) can be made cheaply, as can simple (clean) two stroke engines - I do believe that the electronic motor controllers can probably be made relatively cheaply and that seems to me to be easier than making an IC engine complicated in order to make it perform perfectly ( and probably less efficiently) over the entire rev range!

As for EcoMotors - I never did like the layout of that with it's "pullrods" etc - totally unnecessary, especially when the problem most probably could have been solved in the form of a much neater package, as was used in the successful Commer TS3 (with it's "Sultzer" style engine).
- still, I would never dismiss anything offhand, everything has both good and bad parts!

I (like EC) am not going into details, calculations, etc. (because i'm not really proficient in that area!)

[WilDun]

Yeah EC works.

.......Surely you would be able to keep the transfers open after the exhaust closes if you’re supercharging/turbocharging. ......

Frits said something about that a while ago in this thread (from memory).


Variable valve timing would be easier to achieve at least for intake valves like a VTEC set up or how Suzuki changes the cam timing with centrifugal force. You could also have a power valve on the exhaust to spread the power. ............ I couldn’t help but admire the simplicity and ‘terrible sound’. ....... couldn’t It be muffled down like any other modern car which is virtually silent. ........ Therefore not offending as many eardrum.

Flettner also had something to say on this thread about the supercharger and exhaust noise - (reckoned it was the lobed supercharger which was actually causing most of the noise coming from the exhaust!).

[ken seeber]

Well, been a bit busy on an idea. 2 stroke of course. Nope, not a 54 hp @ 13,624 rpm KZ engine that is dependent on the 3rd divergent cone to be within 0.5 mm in diameter, but something really mundane, perhaps with much reduced HC emissions and fuel consumption. Maybe running at the 3000 rpm range.

More to come on this…possibly. Seeing Hewsa created Oddball, I figured that this is the right place to post it.

So, have had one running, but how do I compare it to a regular carby engine? As the thing is being based on a 100 cc Yamaha KT100J kart engine, I do have something to create a baseline. But how to measure it? Need a dyno.

Essentially out of bits from of years of hording, I made a single speed dyno or, more correctly, a comparator.

As I will be in the power range of 3 - 4 kW, I based it on 5.6kW (7.5 hp) 3 phase elec motor, connected to the engine via a V belt. This will both enable me to start the engine and also act as an absorber, returning power back to the mains. Essentially running at a fixed synchronous speed, apart from slippage, either way. In this case, the motor spins at 3000 rpm and the engine at around 3400 due to slightly different pulley sizes.

344605

How to measure power as there is no torque measurement? What I did is to use a single phase domestic kWhr meter, this being an old “mechanical” type with a rotating disc. A nice feature being as the load reverses, the disc visually changes direction of rotation. This was connected to just one of the 3 phases. So, I could measure power by timing the disc rotation speed, but as the thing now seems to work, will just get a digital ammeter, relying on the kWhr meter to tell me the sense of the current.

Looks a bit shitty, but the focus has been on convincing myself that it might work. I can measure fuel flow by timing the fall in level with the graduated glass tube, turning off the outlet tap of the tank. So, get to the set speed, set a load (based on current) and then measure fuel flow. Take standard engine off, put on THE engine and compare fuel flow rates.

Anyways, that’s the story and here’s a couple of pics:

344602344603344604

[WilDun]

Well, been a bit busy on an idea. 2 stroke of course. Nope, not a 54 hp @ 13,624 rpm KZ engine that is dependent on the 3rd divergent cone to be within 0.5 mm in diameter, but something really mundane, perhaps with much reduced HC emissions and fuel consumption. Maybe running at the 3000 rpm range.

More to come on this…possibly. Seeing Hewsa created Oddball, I figured that this is the right place to post it.


Looks a bit shitty, but the focus has been on convincing myself that it might work. I can measure fuel flow by timing the fall in level with the graduated glass tube, turning off the outlet tap of the tank. So, get to the set speed, set a load (based on current) and then measure fuel flow. Take standard engine off, put on THE engine and compare fuel flow rates.........................

Anyways, that’s the story and here’s a couple of pics:

Well done Ken, still life in the old dog yet!
It interests me very much and I hope it continues to develop successfully. also, old technology never dies (look at Harley) and as you more or less suggest, there is a lot more than racing out there too!

However ....... Must take issue with Husa being considersd the sole originator of the thread, (doesn't matter anyhow) - I suggested it in ESE a couple of times (to take the weight off that very busy thread and maybe give this sort of stuff a chance to be seen) and was asking around if anyone thought it would be a good idea - but Husa was keen and probably thought I was pissing around too much, so just got on and set it up before there were any answers (good on you Husa! ...... motto of the story - don't piss around).
Anyway we have got on ever since and the thread has worked ok - we both give it a good kick up the arse every time it falters -eh Husa? .......(the "Kick Arse Thread"?).

:niceone: - to both you guys.

[WilDun]

The final kick for survival? (the thread? - no, but maybe that as well!) - a very significant last kick it is too (in both cases) I think!

https://www.cycleworld.com/story/bikes/advanced-two-strokes-to-power-formula-1-future/?fbclid=IwAR26FUBYI1IpyFL7HGtKpsFOK967emnAJgbNmXom 2LH5IJuVLOc8QvaLgc0

Are the decision makers wise enough or brave enough to take the plunge?

These guys (Achates) are now well down the track, following on from the successful designs of Junkers, Napier, Sultzer, The Rootes Group (Commer), Foden, who all had successful opposed piston (and piston ported) two strokes over 60 years ago - Junkers really set the ball rolling both before WW2 and during WW2, - they had this engine operating in some of their bombers but were more well known on their E boats. .... then in the fifties, fashion overtook them and they got dismissed by those who should have known better!
Achates are taking it a step further! but this time, is anyone going to be wise enough to see that it could be the best way forward for two stroke suvival?

(BTW the thread is petering out). the two stroke future is still teetering on the brink as well (God forbid that it ever falls back! - that would really end its chances!).
I don't think that there is much that I can do about that (except blabber on ) - so it's goodbye from me and it's goodbye from him (he's not even here either!) :rolleyes:
Time to go and do all the other stuff I really should be doing and pondering my future!

Thanks you guys for all the laughs and good company over the years!
Will.

[190mech]

Will,
I looked at their Youtube vid,interesting as its design is very similar to the Junkers aircraft engine,,then noticed the vid was from 2016..Hope they are still going strong,guess they are trying to keep their old redesign quiet??
https://www.youtube.com/watch?v=JoQkTIfAB2U&feature=youtu.be

[WilDun]

Will,
I looked at their Youtube vid,.....................Hope they are still going strong,guess they are trying to keep their old redesign quiet??



I have just seen this video - sensible guy!
https://www.youtube.com/watch?v=zf6OH4iVUkY

[190mech]

Yes,That was a good vid and looked at other company vids..Looks like they 'have their ducks in a row'..As you have said many times,the big companies have polished the 4stroke turd to a high sheen and dont want to change!A few basic questions from a country boy that has not been answered,Weight?we have 2 crankshafts and gear train to join them.would a triple twin piston weigh less than an equally powered 4poke?Can a single(twin piston) be made to run on a carb,ie chain saw,etc?Are high end electronics required to keep them running?Overhaul costs?Time between overhauls?Will they spin to the high RPMs that the formula 1 folks are looking for?The Junkers was a massive engine,it would be wonderful to see a 'flat' opposed design to give the 4stroke aircraft engines a run for their money..

[WilDun]

Yes,That was a good vid and looked at other company vids..Looks like they 'have their ducks in a row'..As you have said many times,the big companies have polished the 4stroke turd to a high sheen and dont want to change!A few basic questions from a country boy that has not been answered,Weight?we have 2 crankshafts and gear train to join them.would a triple twin piston weigh less than an equally powered 4poke?Can a single(twin piston) be made to run on a carb,ie chain saw,etc?Are high end electronics required to keep them running?Overhaul costs?Time between overhauls?Will they spin to the high RPMs that the formula 1 folks are looking for?The Junkers was a massive engine,it would be wonderful to see a 'flat' opposed design to give the 4stroke aircraft engines a run for their money..

OK OK I was going to move on and forget , but think I do feel the need need to answer all that!
I was once a country boy too (perhaps not as you Southern Boys perceive the term "country boy" but a country boy nevertheless!) but I have a son who lived and worked in Charlotte NC for a few years!

Yes two crankshafts with a gear train but a useful gear train the "idler gear/s" used for a power take off, (only one crankshaft in the case of the Commer/ Sultzer layout - probably no balance shafts required ( I had a ride in a Commer Truck and can vouch for its extreme smoothness.)
Wasn't suggesting it for either racing or crappy little chainsaw type applications (they can do whatever they want). My suggestion (as I also have said many times) is for a constant speed simple clean two stroke driving a generator with no complicated and sometimes not very well all over the whole rev range but something running at reasonably constant revs (at its "sweet spot"), increasing it's efficiency and the electrical stuff controlling the variations in road speed etc.(no tthe engine).so no need to have fancy electronics controlling the motor.
Anyway, wife's calling me, (my turn to do some cooking this evening it seems- gotta go! ------ yes dear!:shit:

[ken seeber]

Wasn't suggesting it for either racing or crappy little chainsaw type applications (they can do whatever they want). My suggestion (as I also have said many times) is for a constant speed simple clean two stroke driving a generator with no complicated and sometimes not very well all over the whole rev range but something running at reasonably constant revs (at its "sweet spot"), increasing it's efficiency and the electrical stuff controlling the variations in road speed etc.(no tthe engine).so no need to have fancy electronics controlling the motor.
:

Will, I had a look at the Achates vid and have to agree, as I think you do, with 190mech that it is a complex affair. But it did look to be a complete package, even with cat converters (I think). However, when you look at any current 4 cyl engine, they are surrounded with bits and pieces, and although fundamentally simple (crank, rod and piston), the valve train offsets that.

How the numbers stack up can only be measured in terms of its commercial success in its most practical application.

Enjoy your dinner? :clap:

[WilDun]

Will, I had a look at the Achates vid and have to agree, as I think you do, with 190mech that it is a complex affair. But it did look to be a complete package, even with cat converters (I think). However, when you look at any current 4 cyl engine, they are surrounded with bits and pieces, and although fundamentally simple (crank, rod and piston), the valve train offsets that.

How the numbers stack up can only be measured in terms of its commercial success in its most practical application.

Enjoy your dinner? :clap:

Thought I might need to stay on another day or so to keep you guys straight! :facepalm:

Yes, best dinner of the week!

As I see it anyway (and I'm right), :rolleyes:
I prefer the Sultzer/Commer layout this is the most compact, one crankshaft with beams/rockers to operate the pistons. rotating at a relatively constant speed as a hybrid powerplant/transmission.
Beams do oscillate of course and normally might need to be heavy, however, the size and weight of these beams could be greatly reduced if the engine runs at constant revs (as it would be when driving a generator) thus removing the stresses involved when an engine constantly accelerates and decelerates, as it normally does today.

Greatly reduced side thrust on the pistons as well.

Reduced manufacturing costs when the cylinder head is eliminated - no leakage problems as there often are with cylinder heads, so lower maintenance costs - Also reduced heat losses, as combustion is contained between the opposed pistons.

As I said, smooth ride, so no balance shafts necessary - smaller lighter flywheel?- I dunno.

Three cylinders working in unison it seems is the ideal scenario both in exhaust interaction and compactness of the package.

Then there is the possibility of two stroke HCCI (petrol) and that could be a winner here and really clinch the deal, as combustion chamber shape might not be nearly as important (or problematic) as they can be in a "normal" two stroke today.

Yes I agree that it might be good in light aitcraft and give the normal four stroke boxer engines a good kick up the arse! ie smoother, good power to weight ratio, good economy also - sump or pump lubrication helping to finally resolve any smoke and pollution (which to my mind is what may have sunk the two stroke forever?? ) pistons not requiring the same heavy lubrication as the rest of the engine might help!

All I can say with certainty is that I won't be the one making all these changes! - but will be watching constantly!

Some possible big changes coming up for me ( family redistribution around the world) - getting my mind to accept that I could possibly be leaving this nice little country is a problem - still not convinced I should! .... We'll see.

[190mech]

Hey Will,
Hope all goes well with you and family,why would anyone want to move from paradise elsewhere?This bit of thread was started from Kevin Cameron's article stating the twin piston 2stroke is the future F1 engine,,Surely it must howl and spin trillions of RPM's to keep the spectators from napping..so a steady state engine wouldnt be what he is writing about..Are we talking the same engine or am I missing something??
Cheers, John

[WilDun]

Hey Will,
Hope all goes well with you and family,why would anyone want to move from paradise elsewhere?This bit of thread was started from Kevin Cameron's article stating the twin piston 2stroke is the future F1 engine,,Surely it must howl and spin trillions of RPM's to keep the spectators from napping..so a steady state engine wouldnt be what he is writing about..Are we talking the same engine or am I missing something??
Cheers, John

John,
It's long story associated with grandkids health problems so very necessary - not what we want to happen of course!

No, not specifically about racing, more about the survival of the two stroke in every aspect of it's existence! - and to be honest I actually only sat down and read through Kevin Cameron's article properly a couple of days ago, so any thoughts from me on this subject are not based on that, but still good news! - I have been (very) slowly working through all this stuff for many years and when I heard of F1 etc taking an interest I have been reviewing things once more..... and I don't expect that anything I think will have much of an impact - I'm just a very interested party i guess!!

The kind of sound we want is really what we become accustomed to I guess - the old "steamies" had to lose their longing for Choo Choo noises, the old racing guys had to forget the sound of the old slow revving singles, so what's really different?

We don't need to incorporate racing rules and sounds etc into our everyday real life (rejuvenated) two stroke design, but we still want to! - we find it hard to change from designs "tainted" by the racing rules which have been deeply ingrained in us! - racing is good, but the real everyday world is a different situation!
So lets break out and explore the big wide "real world"! - Racing is great, no doubt about that, but it's more about personalities than engine noise! - you can hardly even hear the sound of the engines on TV! and when you do hear it, it's not exciting like the sounds in sixties were anyway!
I watch it all the time but we do put up with (for example) a mandatory 250 cc single four stroke putting out less HP than the 250 cc racers of the sixties (eg the Moto Morini from around 1963 - 65, a single cylinder Italian 250cc four stroke capable of beating the Honda fours)! - that's all in the past. - we could ask ourselves, is that really the way to go? - We have however been accepting that for a while and of course its still good racing! .... so perhaps the "retrograde" step of going back to 3 cylinder supercharged two strokes (in the big real world) isn't really so silly after all!

[WilDun]

This thread hasn't moved for a while I see - i decided not to contribute because of some other problems - but then came the lockdowm ...... so ...... just checking - the other 2 threads have been re-lit I see - frightening to see the ESE one just about die!!

[ceci]

This thread hasn't moved for a while I see - i decided not to contribute because of some other problems - but then came the lockdowm ...... so ...... just checking - the other 2 threads have been re-lit I see - frightening to see the ESE one just about die!!


I agree with you, I also break my self-blocking of not writing.
I want to thank the people in this forum for being kind enough to share the details of the NEW DIRECT INJECTION 2-STROKE ENGINES INTERNATIONAL WORKSHOP & CONFERENCE.
This event was publicized on a facebook page before its celebration and since then only here has it had any expectations, which shows the lack of interest on the part of the 2S community to solve the 2S contamination problems.
For me the one that most attracts me is ORBITAl. due to the question of whether a 4S would not be better for these machines (the ones that appear in this movie, for so many hours they are in flight)345069

[WilDun]

KEN SEEBER would be able to tell you all about the Orbital/ Suzuki engine I'm sure - I think he may actually have worked on it! - (he has contributed a lot to this thread) ....... Keep safe in Espana - I have a cousin who also lives there!

[ceci]

KEN SEEBER would be able to tell you all about the Orbital/ Suzuki engine I'm sure - I think he may actually have worked on it! - (he has contributed a lot to this thread) ....... Keep safe in Espana - I have a cousin who also lives there!



Thank you very much, I hope you are well too.
Due to having more time now, movies of all kinds are seen and in this (goodkill) you discover that UAVs spend 12 hours flying, which does not fit with the use of the 2S, the fuel consumption would be 1/3 plus 4S ( larger tank, more weight), to use a normal engine.
And here you discover that what is the degree of efficiency of D-tech since armies always use the best technology

[WilDun]

Thank you very much, I hope you are well too.
Due to having more time now, movies of all kinds are seen and in this (goodkill) you discover that UAVs spend 12 hours flying, which does not fit with the use of the 2S, the fuel consumption would be 1/3 plus 4S ( larger tank, more weight), to use a normal engine.
And here you discover that what is the degree of efficiency of D-tech since armies always use the best technology

Flettner has successfully designed a nice little 700cc twin cylinder liquid cooled lighweight 2S with a balance shaft and last I heard was planning to fit his own (extremely successful fuel injection system developed over the years in his Kawasaki Bighorn) and is currently flying with this engine in his gyrocopter!

[ken seeber]

Ceci,

The Orbital system is pretty neat, one perceived shortcoming being the need for an air compressor, typically around 1/25th of the engine capacity. However, one of the benefits is the very fine atomization of the fuel. This very good atomization allows the use of heavier, thick fuels that can’t be satisfactorily atomized with a single fluid injector, particularly with spark ignition.

Obviously the Ficht single fluid system originally used by the defunct OMC, which I think has evolved into the Etec has got some good qualities as well.
As a result of the fine atomization, Orbital supplies small engines (certainly around 50 cc and maybe more) for use in US drones. The success of these is driven by the US military requirement to use a single fuel type (I think it is Jet Fuel A) for all forms of transport for logistical reasons. See Orbital's website and various associated articles:

https://orbitaluav.com/

https://en.wikipedia.org/wiki/Orbital_Corporation

https://www.australiandefence.com.au/news/sme-spotlight-orbital-little-engines-with-big-plans

Happy reading. I would presume the driveline smoothness and light weight give it an advantage over 4 strokes. I believe some of their flights might be in the order of 16 hours, something that is not yet achievable with electric motors. The engines are far from cheap, the drones returning to base for successive use.

[WilDun]

Ceci,


https://orbitaluav.com/

https://en.wikipedia.org/wiki/Orbital_Corporation

https://www.australiandefence.com.au/news/sme-spotlight-orbital-little-engines-with-big-plans

Happy reading. I would presume the driveline smoothness and light weight give it an advantage over 4 strokes. I believe some of their flights might be in the order of 16 hours, something that is not yet achievable with electric motors. The engines are far from cheap, the drones returning to base for successive use.

I guess time has caught up with me and I'm still in the nineteen eighties! so far as Orbital are concerned! - and I guess Ken that you never were involved with this stuff either!?- but there you go, time always catches you out -

[tjbw]

I guess there's nothing oddball about a triple rotor Wankel, but this one sure sounds good:

https://youtu.be/nOyOYLZWcBI

[ceci]

Ceci,

The Orbital system is pretty neat, one perceived shortcoming being the need for an air compressor, typically around 1/25th of the engine capacity. However, one of the benefits is the very fine atomization of the fuel. This very good atomization allows the use of heavier, thick fuels that can’t be satisfactorily atomized with a single fluid injector, particularly with spark ignition.

.

Thank you all, you are very kind and that is appreciated
Most researchers refuse to use a compressor (for example: IAPAC by Pierre Duret, etc.).
The evidence forces its use (example: Yoichi Ishibashi, who in the end incorporated it).
I am in favor of it and I am convinced of its obligatory use, since it will provide benefits such as an increase in the volumetric performance of the engine.
These photos are from the University of Pisa (Italy) another attempt without a compressor, which like the rest has not worked

[lohring]

Isn't the main issue with the Orbital system rpm limitations? For aircraft and car engines that shouldn't be a problem, but for racing engines it is.

Lohring Miller

[WilDun]

Isn't the main issue with the Orbital system rpm limitations? For aircraft and car engines that shouldn't be a problem, but for racing engines it is.

Lohring Miller

For aircraft engines I believe that high torque is most important in order for the engine to be able to swing a larger and more efficient prop and also run at it's RPM sweet spot for efficiency (ie if you are wanting to run it at crankshaft RPM). - Although gear reduction is mostly used today for smaller engines to run these more efficient props (engine efficiency might be lost through the transmission) and add weight and cost - A competition engine is another subject of course! Anyway .... horses for courses I guess! - There are some contributors here who are much much more clued up than I am about this - (I'm just here to try and pry them out of the woodwork! :msn-wink:).

[ceci]

Isn't the main issue with the Orbital system rpm limitations? For aircraft and car engines that shouldn't be a problem, but for racing engines it is.

Lohring Miller
KTM investigated to solve this possible deficiency, but this investigation focused on only one of the two focuses of work. In the creation of the primary spray tried to expand the RPM range
345111

[Flettner]

isn't it best to just banish the exhaust ports to the opposite end of the cylinder, out of harms way?
48 x 48 x 2

[WilDun]

isn't it best to just banish the exhaust ports to the opposite end of the cylinder, out of harms way?
48 x 48 x 2

Guess if you're talking 'opposed pistonI' , then I think so too - I do like the compact Commer TS3 layout though! - (even with the James Watt style beams/rockers! :rolleyes:) - and if it's too hot for an A/A exhaust piston, (as you suggested earlier - in ESE?) why not use a lightweight cast steel crown?

[Flettner]

[QUOTE=WilDun;1131157973]Guess if you're talking 'opposed pistonI' , then I think so too - I do like the compact Commer TS3 layout though! - (even with the James Watt style beams/rockers! :rolleyes:) - and if it's too hot for an A/A exhaust piston, (as you suggested earlier - in ESE?) why not use a lightweight cast

Or made of something else.
No cylinder heads, no balance shaft needed, no carburetors, assimetrical timing. Lots of benefits I think.
175cc via two 48 x 48, ends up not that much taller than a standard engine if you include the spark plug and plug cap.

[WilDun]

[QUOTE=WilDun;1131157973]Guess if you're talking 'opposed pistonI' , then I think so too - I do like the compact Commer TS3 layout though! - (even with the James Watt style beams/rockers! :rolleyes:) - and if it's too hot for an A/A exhaust piston, (as you suggested earlier - in ESE?) why not use a lightweight cast

Or made of something else.
No cylinder heads, no balance shaft needed, no carburetors, assimetrical timing. Lots of benefits I think.
175cc via two 48 x 48, ends up not that much taller than a standard engine if you include the spark plug and plug cap.

Yep, agree! -but with that basic layout in mind, we might be able to do away with the deeply embedded belief in our heads that the Two Stroke Bore/stroke ratio needs to be roughly "square" - this could give us some more freedom to keep down piston speeds! (not talking racing here of course, just my hobby horse (deluded maybe) ie a two stroke generator powerplant for all sorts of purposes!

Made of something else? I'm not really up there in the world of metallurgy (or anything) - just suggestions, with nothing tested in the real world in a scientific manner, but I'm sure there is a simple answer staring us in the face. (that's going to be easier to overcome than this virus trying to wipe us out!)

[Flettner]

Locked in my shed for four weeks, yay. But not all beer and skittles, I was lucky enough to get a large pre paid gearbox order just before the lock down. So I'm in the process of getting that sorted before I get onto home jobs. So, good I guess, keep the bank off my back.
Five of these H6 Subaru units and four EA Subaru boxes.

[Flettner]

In saying that, here is something I prepared earlier.

[WilDun]

Hard times! - It sure brings it back to all of us all just how helpless we are - not as clever as we think we are and this emergency makes the process of reviving the two stroke look very insignificant indeed!

BTW - I recognize that crankcase/gearbox as being "one size fits all" for your projects! - also remember the EA 81 from way back

[WilDun]

This thread has been here for well over 5 years now and that's not bad! - It was initially set up in order to get all this sort of stuff extricated from the main subject going on in ESE - there was so much experimental tuning conversations going on there at the time (and that after all was its original purpose) - however, most of the historic and futuristic stuff was just being ignored and so, tended to just disappear! - it was also getting tangled up with and confusing all the good tuning questions and answers as well.

However, it seems that even though it has served its purpose, there isn't a lot of interest anymore - but it was good while it lasted! - and it was all light hearted and good fun - but maybe this part of the forum isn't really the place for people who are interested in what happened before, things which actually led up to and allowed us to have the machinery we have today! :facepalm:

People who are really interested in 'motorcycles' (ie as opposed to 'boneheaded' showmen) really need to know the history and have at least some vision of the future in order to prevent bikes being legislated out of existence! :mellow:

[190mech]

Hi Wil,
Ive followed motorcycles since I was a young man as they always had the highest performance that a common man could afford and still do..Very many engines of all types have lots of design flaws and those turds are polished by the engineering and advertising departments till they shine with a high luster!The public buys them up and more polish gets added yearly..The ones who really know are the poor bastards that have to service and keep them running!I hope the future will bring the 'simple' 2stroke engine back so we dont have to worry with those thousands of 4stroke parts thrashing away against each other!
As to aircraft engines,the Pratt and Whitney PT6A is a much loved engine(by pilots),but to many of us mechanics its a POS,,but what do we know?Its a multimillion dollar industry that requires constant maintenance which puts money in lots of peoples bank accounts,sooo I guess its all good..
I dont think this thread will die as long as there are free thinking folk(have seen lots here!),so lets post when we find a head scratcher engine and hopefully some bright minds will grasp a concept and carry on!!

[WilDun]

Hi Wil,
Ive followed motorcycles since I was a young man as they always had the highest performance that a common man could afford and still do..Very many engines of all types have lots of design flaws and those turds are polished by the engineering and advertising departments till they shine with a high luster!The public buys them up and more polish gets added yearly..The ones who really know are the poor bastards that have to service and keep them running!I hope the future will bring the 'simple' 2stroke engine back ........
.....I dont think this thread will die as long as there are free thinking folk(have seen lots here!), so lets post when we find a head scratcher engine and hopefully some bright minds will grasp a concept and carry on!!

At least someone must be looking in here (you being one of them!) and you do make some very good points! (and I have been interested in motorcycles for over 60 years.).

Discussing the "simple" two stroke - the more simple the better of course! (or as Frits always says KISS) and yes, simple would be nice, but that simplicity (crankcase scavenged, oil mixed with the fuel, the oil eventually collecting in the exhaust, fresh charge escaping into the atmosphere, NOX emissions (apparently caused by 'squish') etc etc - all no problem in racing machinery ..... but in the everyday world??

I think we need to consider the bigger picture! - Racing only follows on from the machinery we are familiar with every day, - unfortunately, at the moment that doesn't include the two stroke.

We need to acknowledge that the two stroke isn't mainstream anymore and other engines have been very successful (most often four strokes) but if we can clean up the two stroke, it'll easily get to that mainstream position!

There are lots of others around here who are well educated in engine design, some free thinking and some actual doers! - some are all of these! and they are the ones who will lead the way and make progress! (ie if some big company doesn't appear and just take everything!).

I acknowledge that I don't figure much in the above categories!

[pete376403]

At least someone must be looking in here (you being one of them!) and you do make some very good points! (and I have been interested in motorcycles for over 60 years.).

Discussing the "simple" two stroke - the more simple the better of course! (or as Frits always says KISS) and yes, simple would be nice, but that simplicity (crankcase scavenged, oil mixed with the fuel, the oil eventually collecting in the exhaust, fresh charge escaping into the atmosphere, NOX emissions (apparently caused by 'squish') etc etc - all no problem in racing machinery ..... but in the everyday world??

Also another long term bike follower and previous owner of two strokes - however, doesn't uniflow answer the problems of crankcase scavenging? Definitely a little more complicated than your average Villiers but no more than current four strokes.

[WilDun]

Also another long term bike follower and previous owner of two strokes - however, doesn't uniflow answer the problems of crankcase scavenging? Definitely a little more complicated than your average Villiers but no more than current four strokes.

Yes I agree wholeheartedly and have been a fan of this layout for as long as I have been interested in bikes! - I was inspired by the commer two stroke diesel truck engine, the Sultzer engine and of course the Junkers - but to be honest it isn't all that complicated in either the Commer or the Junkers engines! - they were lubricated by seperate oil as well - and they were all successful too! - so why not a modern day petrol one?
When you look at a modern day four stroke the head is just as tall as the bottom end and has a helluva lot of moving parts ..... and a head gasket as well!

[lohring]

Fifty years ago I thought a 3 cylinder sleeve valve two stroke like Ricardo's design would be a good replacement for the 6 cylinder four strokes used in light airplanes. I did a market survey and it looked like there would be a demand for a smaller, lighter engine with the same power. However, I had no idea of what the development and licensing costs would be. Those costs have doomed many simple upgrades to legacy engines that use 1930s technology. The collapse of the new light plane market means no one will do more than maintain the existing engines. Today the trend is away from IC engines everywhere. We're stuck with looking at the inventive engines designed in the past.

Lohring Miller

[WilDun]

I guess that that those old aircraft flat fours and sixes have served us well and a helluva lot of them have been built!

Along with Harley Davidson and Briggs & Stratton etc they have been quietly powering things most of our lives without even being noticed and as you say, modified only by embellishments but still using nineteen thirties technology!
To be honest, they were really the (levelled) pinnacle of development for many of us and anything since including the growth of the two stroke and the four stroke technology (with all sorts of additions to try and keep it on top) are only spikes in development. - a bit unfair assessment of course, but with a ring of truth! ........ but this "outdated technology still managed to keep a lot of investors with steady incomes.

Now electric is having a go! - I wonder if it will break the love affair with the pre and early post war technology? - or will the virus destroy development and change everything?

[pete376403]

I guess that that those old aircraft flat fours and sixes have served us well and a helluva lot of them have been built!

Aircraft will rarely be the place where new or even different technology will be tried - the exception of course being during wartime - as 20,000ft is not the place to find it wasn't such a good idea after all.

[WilDun]

Aircraft will rarely be the place where new or even different technology will be tried - the exception of course being during wartime - as 20,000ft is not the place to find it wasn't such a good idea after all.

Yes and something reliable, even if not perfect would be preferred in that case! ........ but what excuse did Harley Davidson and Briggs & Stratton have? - just let 'well enough' be I guess! - a far cry from the Napier Nomad (a great example of a complicated two stroke!).

https://ww2aircraft.net/forum/threads/napier-nomad-engine-data.31895/

https://oldmachinepress.com/2019/08/05/napier-nomad-compound-aircraft-engine/

[Flettner]

electric? not so fast. I want / need to be able to fly my gyro four hours without landing and refueling. IC will do that for me at the moment, electric would be closer to maybe half an hour, at the moment. Not enough.

[WilDun]

electric? not so fast. I want / need to be able to fly my gyro four hours without landing and refueling. IC will do that for me at the moment, electric would be closer to maybe half an hour, at the moment. Not enough.

See what I mean? - all you need is an old EA81 (pushrod) Subaru for starters, get 'that guy' from Waikato to give it a going over and hey presto! - everything's there , like a four stroke which revs low enough (to manage without a reduction gearbox) and is economical and uses the 'thirties' technology we were discussing - everything you need! but if you want something lighter then you can try a two stropke (they are available from 'that guy' too!) :D

[lohring]

Napier (https://en.wikipedia.org/wiki/D._Napier_%26_Son) was at the forefront of IC engine development for a long time. They developed fighter aircraft engines with very high power for their frontal area starting the W layout Lion (https://en.wikipedia.org/wiki/Napier_Lion) and ending with H design Sabre (https://en.wikipedia.org/wiki/Napier_Sabre). The Deltic (https://en.wikipedia.org/wiki/Napier_Deltic) was probably the last successful refinement of the opposed piston engine. In the end, these engines complexity was their downfall. In aircraft we have turbines, and in two strokes we have crankcase scavenged tuned pipe engines. My lawn mower and weedeater have an electric motors. Less is more.

Lohring Miller

[190mech]

In aviation there is still a need for reliable mid horsepower work engines and the old school radial engine takes care of that at a fraction of the cost of a turboprop engine..I work with some ag aircraft(crop duster) guys and they still prefer the radial for low overhaul cost,cheap to maintain,low fuel burn..The bigger players prefer turbines,but must work year around flying across the nation for work to keep up with their million dollar ag plane payments.insurance.and maintenance costs in check..Its their choice!
Back to the loved 2stroke,their beauty is every stroke is a power stroke!No wasted pumping stroke..I am all for different 2stroke configurations,oiled bottom ends is even better!I'm not an engineer,but feel a 2stroke engine can deliver more even torque at a lower RPM with a smaller simpler size than the normal stuff...

[WilDun]

Napier (https://en.wikipedia.org/wiki/D._Napier_%26_Son) was at the forefront of IC engine development for a long time. They developed fighter aircraft engines with very high power for their frontal area starting the W layout Lion (https://en.wikipedia.org/wiki/Napier_Lion) and ending with H design Sabre (https://en.wikipedia.org/wiki/Napier_Sabre). The Deltic (https://en.wikipedia.org/wiki/Napier_Deltic) was probably the last successful refinement of the opposed piston engine. In the end, these engines complexity was their downfall. In aircraft we have turbines, and in two strokes we have crankcase scavenged tuned pipe engines. My lawn mower and weedeater have an electric motors. Less is more.

Lohring Miller

Lohring,
Much as I hate to admit it, in the mechanical world, most of the innovations were in the twentieth century and I hope we are now sifting through the tailings to find any discarded gems and refine them. The electronics world continues upward but it's very fragile and is vulnerable to outside interference (in all sorts of ways) and I don't think it's sane to rely on it as much as we do!).
I think that the only upside of this virus is that it has made many us forget the world of fantasy we have been living in, take stock of just where we actually do stand in terms of human existence- and settle for less! ....... (which is more! :niceone:).

[WilDun]

In aviation there is still a need for reliable mid horsepower work engines and the old school radial engine takes care of that at a fraction of the cost of a turboprop engine..I work with some ag aircraft(crop duster) guys and they still prefer the radial for low overhaul cost,cheap to maintain,low fuel burn..The bigger players prefer turbines,but must work year around flying across the nation for work to keep up with their million dollar ag plane payments.insurance.and maintenance costs in check..Its their choice!
Back to the loved 2stroke,their beauty is every stroke is a power stroke!No wasted pumping stroke..I am all for different 2stroke configurations,oiled bottom ends is even better!I'm not an engineer,but feel a 2stroke engine can deliver more even torque at a lower RPM with a smaller simpler size than the normal stuff...

I guess those AG planes were originally built to take advantage of the thousands of cheap, well developed radial engines which were left over from WW2!

Two stroke power? - Yes but it will still face opposition by many quoting from the same old book of prejudices against it, we will have to rewrite the book and give it a new presentation! - today's upgraded (but still traditional) design will convince no one to change - present two stroke design (as I see it) will work well for competition perhaps - but not universally be accepted, powering other vehicles and in this important area it has already been well and truly stymied! - but there's no profit in being a pioneer either!

[Flettner]

Don't worry guys, I got this😆
Uniflow for aviation, two cranks , no need for counter balance shaft and there is an exciting option of twin counter rotating props. Any engine IC of any worth still needs a gear reduction anyway, if you are looking for efficency.
Will D, my Subaru EA81 powered gyro even has an Autoflight gear reduction ( torque multiplier ) or it would be a slug to fly.
Splitting the exhaust away from the inlet has big advantages.
Compare my Uniflow 440 engine to say my EA81.
Uniflow has two cranks but the same amount of connecting rods and crank journals as the EA ( so could be argued the same), Uniflow has no heads or valves or push rods or rockers or camshaft. Same number of pistons. Uniflow could live with two carburetors or FI same as the EA. Uniflow has four gears, EA has two gears ( cam drive ) plus two redution hears, so the same, EA has and oil pump, Uniflow not. EA has a sump, Uniflow not, same amount of spark plugs on both.

So only thing extra on the Uniflow is some reed valves.

EA, extra is, cam, lifters, push rods, rockers, valves, sump, oil pump, heads, you have to take into account the gear reduction so same number of gears and it only fires half as often.

Seems the Uniflow is the clear winner. Make it HCCI and I'm sure it would be so efficient, it would be making fuel. 😆

[Flettner]

A clean sheet required, and clear workshop bench.

[WilDun]

A clean sheet required, and clear workshop bench.

Oh well, sorry for my ignorance in the engine/prop department ( I tend to be looking from the perspective of light fixed wing aircraft) but I know I probably get people so wound up sometimes that they might feel the need to correct me ! )..... and that's great, ..... I hope they do - that way I can learn more! :D- )
Also, it looks like I possibly could have been wrong in the foundry thread in thinking that you were reviving the Cre'cy again ! - I could be forgiven for thinking that though! ........ and now, two cranks on a new aviation engine idea - never ending!
Good comparisons given between it and the EA81! (don't scrap the EA81 just yet though!) .... anyway we'll wait and see everything unfold.
.
Now that the Oddball thread and the Foundry thread are both going again, - the ESE thread has decided to stall! - that's unbelievable! it used to be packed with so much stuff it could hardly breathe! - someone needs to kick start it as well guess, - not me, it's not my domain!.

I guess the Virus is having an impact because it has closed down all Bucket Racing activity!!

[lohring]

Places where high continuous power is needed (ships, airplanes) will use IC engines for a long time. However, I worked at an electric boat company (http://www.gdeb.com/) that has been building electric powered "boats" for a very long time. Today these "boats (https://www.popularmechanics.com/military/navy-ships/a29798485/japan-lithium-ion-submarine/)" are using lithium ion batteries. The batteries are replacing sterling engine systems. Noisy diesel generators are still used for recharging. Aircraft need lighter power plants than ships. Even so, short haul planes are currently being designed for battery electric power. See https://www.businessinsider.com/electric-planes-future-of-aviation-problems-regulations-2020-3

My favorite spray plane pilot (https://www.amazon.com/skin-teeth-cropdusters-story/dp/0965747301) survived flying biplanes in the early days of post war aviation. I had a ride in his N3N (https://en.wikipedia.org/wiki/Naval_Aircraft_Factory_N3N) when he was still flying. Those big radials are impressive. These days he's 88 and flies as a passenger in his wife's Bonanza. He still does aircraft inspections as an ATA certified mechanic.

Lohring Miller

[Flettner]

lohring, boats easy, a bit of weight in the right place is a good thing and if it all stops no big deal.
Autogyro is a power hungry aircraft, power density is top priority. And if it all stops you aren't just floating around, you are ' floating' down. In fact the modern gyro didn't really shine until a suitable twostroke turned up. Early examples used McCullough military drone engines, 72 HP, the weight of a loaf of bread (almost) suddenly the personal gyro was a real thing. Thank you Dr Benson.
In my opinion a uniflow twostoke would be the ultimate IC power plant for a gyro, power and efficiency.

[WilDun]

Places where high continuous power is needed (ships, airplanes) will use IC engines for a long time. However, I worked at an electric boat company (http://www.gdeb.com/) that has been building electric powered "boats" for a very long time. Today these "boats (https://www.popularmechanics.com/military/navy-ships/a29798485/japan-lithium-ion-submarine/)" are using lithium ion batteries. The batteries are replacing sterling engine systems. Noisy diesel generators are still used for recharging. Aircraft need lighter power plants than ships. Even so, short haul planes are currently being designed for battery electric power. See https://www.businessinsider.com/electric-planes-future-of-aviation-problems-regulations-2020-3

My favorite spray plane pilot (https://www.amazon.com/skin-teeth-cropdusters-story/dp/0965747301) survived flying biplanes in the early days of post war aviation. I had a ride in his N3N (https://en.wikipedia.org/wiki/Naval_Aircraft_Factory_N3N) when he was still flying. Those big radials are impressive. These days he's 88 and flies as a passenger in his wife's Bonanza. He still does aircraft inspections as an ATA certified mechanic.

Lohring Miller


We still (as far as I know) use DH Beavers for fertiliser drops in the hill areas of this country (NZ) - they were first brought in for that purpose from Canada a long time ago - I think the in late fifties and were assembled here by the father of a friend of mine, and of course used the big radial engines - so that shows their reliability!
We also have a home grown topdresser here called a Fletcher, which has been operating from those days as well and it used a Lycoming or Continental flat 6 and has been around for a very long time as well - there was a modified version fitted with a turboprop (now called Cresco) - and unfortunately just last week, one crashed on takeoff, killing the pilot.

https://en.wikipedia.org/wiki/PAC_Cresco

Neil, ( I know that we're deviating a little from the bike stuff but it's still relevant so long as we get back again I hope) ....... I was familiar with the contra rotating twin prop scenario - In N. Ireland, where I grew up, our farm was close to an RAF base operating the 4 engined Shackleton bombers which used the RR Griffon engines (with contra rotating twin prop).

https://www.pinterest.nz/pin/382383824590278960/

Also close was a RN Base which operated the Fairey Gannet (carrier anti submarine aircraft) which used Twin Mamba Turboprop engines coupled to a twin prop setup - these engines could be used as seperate engines as well! but... noisiest things on the planet!

https://www.faaaa.asn.au/heritage-fairy-gannet/

[Flettner]

Noisy, they were not doing it right.

[WilDun]

Noisy, they were not doing it right.

Not sure if it was the engines (unlikely) or the props - probably shock waves from the prop tips - but bloody noisy .... they easily rivalled the Harvards at takeoff!

[husaberg]

Not sure if it was the engines (unlikely) or the props - probably shock waves from the prop tips - but bloody noisy .... they easily rivalled the Harvards at takeoff!

https://youtu.be/elENLa01XHA?t=993


contra-rotating propellers have been found to be between 6% and 16% more efficient than normal propellers.
However they can be very noisy, with increases in noise in the axial (forward and aft) direction of up to 30 dB, and tangentially 10 dB. Most of this extra noise can be found in the higher frequencies. These substantial noise problems limit commercial applications
https://www.rcgroups.com/forums/showatt.php?attachmentid=2815700

[Flettner]

like I said, they are not doing it right, are they. Thats 'olden days' technology.

[Flettner]

Will D, dont worry Im not going off in an aviation direction just yet. I'll get this 175 uniflow running first, in an off road bike frame, then we will see whether to take it further.
Although the next step would be a twin cylinder gyro engine, I've got a spare gyro frame too, perhaps even the counter rotating 'stealth' props.
Finally got down to some serious pattern making this evening, the pattern making port must have opened in the cosmos.

[lohring]

You can't believe the lengths they go to in submarines to run quiet. The passive sonars can pick up the noise from geared turbines half way around the world under the right conditions. They can identify an individual sub from its noise signature. All the machinery is attached on very carefully designed noise reducing mounts. The crew wears sneakers. Sure, the early nuclear boats could make over 30 knots submerged, but they often ran at more like 5 knots with turbo electric generator driven electric motors. The Tulibee was the first all electric drive nuclear submarine. It was rumored to have surfaced next to a US carrier completely undetected. The next try was the Glenard P. Lipscomb, a modified Sturgeon class boat, but it was not as successful and wasn't the basis for the Los Angeles class.

At the time electric motors couldn't reliably provide the power for high speeds. I don't know as much about the modern boats, but they use ducted propellers to reduce propeller noise. They are covered in special noise reducing coatings. All nuclear submarines have an electric motor directly connected to the propeller shaft for quiet running. The latest ballistic missile submarine class will use a modern all electric drive system. The modern diesel electric boats most navies have are serious threats in coastal waters because they are quiet. Nuclear submarines main advantage is range submerged. Recharging batteries is dangerous because it is noisy and occurs near the surface.

I'm surprised I haven't heard about any fuel cell research for submarines. It would seem to be ideal where more power is needed than batteries can provide. Costs are an issue for smaller power plants (cars) but aren't as much a consideration for the military. The fact that the Japanese chose batteries over fuel cells for their submarine is an indicator of the relative state of development. Also, hydrogen is very dangerous, especially in an enclosed space like a submarine.

Lohring Miller

[Frits Overmars]

hydrogen is very dangerous, especially in an enclosed space like a submarine.I'd say that only in enclosed spaces is hydrogen dangerous. Leaked hydrogen will disappear immediately, contrary to petrol fumes or LPG that will form invisible but highly flammable puddles.

[Michael Moore]

I'm surprised I haven't heard about any fuel cell research for submarines.

FWIW, there are Stirling engine generators designed for subs, which make use of the temperature differential between the inside and all the cold water on the outside. But these seem to be only for use to recharge batteries, they don't put out enough for e-drives.

https://saabgroup.com/media/stories/stories-listing/2015-02/the-secret-to-the-worlds-most-silent-submarine/

cheers,
Michael

[husaberg]

You can't believe the lengths they go to in submarines to run quiet. The passive sonars can pick up the noise from geared turbines half way around the world under the right conditions. They can identify an individual sub from its noise signature. All the machinery is attached on very carefully designed noise reducing mounts. The crew wears sneakers. Sure, the early nuclear boats could make over 30 knots submerged, but they often ran at more like 5 knots with turbo electric generator driven electric motors. The Tulibee was the first all electric drive nuclear submarine. It was rumored to have surfaced next to a US carrier completely undetected. The next try was the Glenard P. Lipscomb, a modified Sturgeon class boat, but it was not as successful and wasn't the basis for the Los Angeles class.

At the time electric motors couldn't reliably provide the power for high speeds. I don't know as much about the modern boats, but they use ducted propellers to reduce propeller noise. They are covered in special noise reducing coatings. All nuclear submarines have an electric motor directly connected to the propeller shaft for quiet running. The latest ballistic missile submarine class will use a modern all electric drive system. The modern diesel electric boats most navies have are serious threats in coastal waters because they are quiet. Nuclear submarines main advantage is range submerged. Recharging batteries is dangerous because it is noisy and occurs near the surface.

I'm surprised I haven't heard about any fuel cell research for submarines. It would seem to be ideal where more power is needed than batteries can provide. Costs are an issue for smaller power plants (cars) but aren't as much a consideration for the military. The fact that the Japanese chose batteries over fuel cells for their submarine is an indicator of the relative state of development. Also, hydrogen is very dangerous, especially in an enclosed space like a submarine.

Lohring Miller


FWIW, there are Stirling engine generators designed for subs, which make use of the temperature differential between the inside and all the cold water on the outside. But these seem to be only for use to recharge batteries, they don't put out enough for e-drives.

https://saabgroup.com/media/stories/stories-listing/2015-02/the-secret-to-the-worlds-most-silent-submarine/

cheers,
Michael
I remembered reading about this
https://nationalinterest.org/blog/buzz/sunk-during-wargames-2005-special-swedish-submarine-destroyed-aircraft-carrier-77116

However, the two-hundred-foot-long Swedish Gotland-class submarines, introduced in 1996, were the first to employ an Air Independent Propulsion (AIP) system—in this case, the Stirling engine. A Stirling engine charges the submarine’s seventy-five-kilowatt battery using liquid oxygen.

With the Stirling, a Gotland-class submarine can remain undersea for up to two weeks sustaining an average speed of six miles per hour—or it can expend its battery power to surge up to twenty-three miles per hour. A conventional diesel engine is used for operation on the surface or while employing the snorkel. The Stirling-powered Gotland runs more quietly than even a nuclear-powered sub, which must employ noise-producing coolant pumps in their reactors.

[lohring]

The coolant pumps were a big noise source. I worked on the Narwhale, powered by a direct drive turbine and a natural circulation reactor. It was supposed to be a modified Sturgeon class boat, but had to be a larger diameter to fit the power plant. It's huge cost is the main reason I say cost doesn't matter much to the military. The boat was very silent and probably was mostly used for espionage. Everything about its career is probably still classified. The attack subs often had over 6 month deployments, often close to Soviet bases. A neighbor of ours was depth charged during one mission. We had great picnics on the leftover steaks left from these missions. The sub crews were treated very well during the cold war.

Back to two strokes, my favorite IC engines.

Lohring Miller

[WilDun]

We might have appeared to be getting off track, but I guess this thread is really here to allow us to get off track! - because, in looking at the big picture, we can find a lot of ideas and information (except for nuclear power and total silence :laugh:!) from there which can be useful and transferable to our little picture which is (often, but not exclusively) concerned with the two stroke engine!

But ..... we still need to change to save the two stroke.

The expansion chamber (which does increase the power a lot), only does it well within a certain rev range - so really only in competition!
When the current types of chambers are used, they are there to augment the power delivery of the engine and when it gets out of its happy range it has to be augmented further with power valves and various other "improvements"!
So, I believe that in a road going two stroke, the expansion chamber as we know it is a useless piece of equipment - it collects oil, and only works when it gets "on the pipe" - this is the last thing we need for that purpose! (I started riding in the days of the T20 Suzuki and the Kawasaki H1 etc so I've been there!) - all fast but low in the revs they became gutless, smoky heaps of crap! - the exhausts ended up twice the weight they were after a year or so ...... and I loved them! - dopey bugger that I was!
The other problem is oil in the petrol (despite arguments for, - also the other unseen pollutants!) - that is what has more or less relegated it to the scrap heap instead of being used for transport
Whether we accept it or not, this is a fact - it has happened - are we are just too blind to see?

We need to redesign the whole thing (ie the two stroke engine) to make any progress in restoring it to it's rightful place! - racing is a spinoff from transport, (that's where the money is made)!
The people most needing motorcycles to use for transport are in emerging countries - they are buying bikes by the million .... in the form of four strokes!

Sorry, rant! - but am I wrong?

[dangerous]

I'd say that only in enclosed spaces is hydrogen dangerous.

ive never been acused of that... but methane... welllllllll

[lohring]

I keep going back to turbos. They are used in the big marine two strokes as well as the Detroit Diesel uniflow two strokes. Neither use tuned exhausts. Variable vanes in the turbine and compressor can allow the turbo to run over a wide range. Electric drives can run the compressor when the turbine doesn't develop enough power. When the turbine has excess power, the motor becomes a generator, returning power to batteries. Formula one has been running systems like this. Regenerative braking can be added. Modern electronics make all this work. The problem is that it's way more complex and still less efficient than a battery/electric power plant. Fuel cells should be promising where batteries are too large or heavy. Today fuel cells are still (much?) more expensive.

Lohring Miller

[WilDun]

"Horses for Courses" applies here - these solutions in huge two strokes are good and work very well in the environments they are used in - in our case, we normally use them in motorcycles etc and so they need to be compact and simple as possible at the same time.
My contention is still that a supercharger or turbocharger can be made as an integral part of the engine and so more compact than a big expansion chamber. It could be argued that the chamber is a lot cheaper solution, but then it is only good within a certain rev range and is less than perfect outside this range! whereas these days a supercharger can be used over a wide range - a turbo can be too and with the added advantage of less power robbing. - both it seems can work well together, but that might be starting to get a bit complicated and bulky for our situation!
(these are my opinions of course and I stand to be corrected!).

[lohring]

DKW tried almost everything you could thing of in two strokes before the tuned pipe era. Many are shown here (https://www.odd-bike.com/2014/02/dkw-supercharged-two-strokes-force-fed.html). The tuned pipe engines were simpler and more powerful, not to mention less expensive. Big outboards use pipe length switching to get suitable tuned exhausts in a compact package. BRPs big outboards are at the leading edge in this and other two stroke technology. Their advantage is that they weigh less and are simpler than supercharged four strokes of the same power. Note that the Mercury outboards use screw compressors. Those are the most efficient in moderate sizes. I think small engines would do better with piston compressors. But wait, that's what crankcase compression engines use. LOL

Lohring Miller

[WilDun]

DKW tried almost everything you could thing of in two strokes before the tuned pipe era. Many are shown here (https://www.odd-bike.com/2014/02/dkw-supercharged-two-strokes-force-fed.html). The tuned pipe engines were simpler and more powerful, not to mention less expensive. Big outboards use pipe length switching to get suitable tuned exhausts in a compact package. BRPs big outboards are at the leading edge in this and other two stroke technology. Their advantage is that they weigh less and are simpler than supercharged four strokes of the same power. Note that the Mercury outboards use screw compressors. Those are the most efficient in moderate sizes. I think small engines would do better with piston compressors. But wait, that's what crankcase compression engines use. LOL

Lohring Miller

Lohring,
I agree with most of what you are saying and that new two stroke V4 aero engine (I think it was you sent in a link for) seems to be very compact and embodies most of the stuff that will be needed for the two stroke to get ahead in future (and it doesn't use an expansion chamber!) but I'm sure it'll be expensive!
For Outboards and Skidoos, development of the two stroke has continued over the years and hopefully those manufacturers will come up with a workable engine which is lightweight, economical, compact and affordable for everyone - in all sorts of vehiclesl

I still haven't looked at the link you put in as yet, - but I think the piston pump is a good idea (not the "under piston" pump though!).
The split single (with a bit of imagination) could be seen as close cousin of the opposed piston engine - (I'm not so keen on the combustion chamber area it produces!) but this arrangement did work well, Puch being a good example.
The Trojan light delivery van/truck in Britain used a split single for many years, it had sump lubrication and a piston type charge pump, instead of using the crankcase as a pump.

I suspect that this system largely disappeared because it wasn't following the trend in the competition environment, (just not cool anymore!). It did however make perfect sense and was totally adequate for everyday vehicles.
Really, it was racing rules and the banning of superchargers which robbed the engine world of the benefits of these and so this ushered in expansion chambers (a way round the problem) - they were not actually recognized as superchargers ... effectively though, they were superchargers - (as most people now realize!) - but are normally most useful within a limited rev range, as dictated by competition!
They did do a good job in racing of course, but for the average motorcyclist, I feel that they were of no benefit whatsoever!

As you probably know, I still have high hopes for the opposed piston layout!

(and as usual, everything only my opinion!).

[WilDun]

Lohring,
Had a look through the link on DKW - true innovators - very interesting!
Piston pumps good, but maybe not so good in the compactness department as the screw compressor!

[ceci]

I think small engines would do better with piston compressors.

Lohring Miller

The use of a piston pump is not only limited to one function.
In addition to supercharging, it can be used at the same time to make a layered load, with the best direct injection method that works "pneumatic" on mopeds and UAVs.

[lohring]

There are several advantages to piston compressors. First, they can be used to balance the engine. Second their delivery is pulsed and can be timed to arrive at the cylinder at the right time. One of the very first two strokes took advantage of all this in 1878.

Lohring Miller

[Frits Overmars]

There are several advantages to piston compressors. First, they can be used to balance the engine. Second their delivery is pulsed and can be timed to arrive at the cylinder at the right time. One of the very first two strokes took advantage of all this in 1878.Don't you love the simple but highly efficient carburetor de-icing system? The exhaust ports blow straight into the carb bellmouth :D.

[WilDun]

The use of a piston pump is not only limited to one function.
In addition to supercharging, it can be used at the same time to make a layered load, with the best direct injection method that works "pneumatic" on mopeds and UAVs.

Ceci
Pretty sure Ken Seeber would know something about that, he worked for the company which invented and developed that system. (Orbital Australia).



Don't you love the simple but highly efficient carburetor de-icing system? The exhaust ports blow straight into the carb bellmouth :D.

Frits,
Yes - I know - joke!
But ..... Not so long ago (on some of these threads), we were discussing the benefits of having hot exhaust gases coming back into the cylinder from an expansion chamber to enhance and heat the charge for HCCI! ...... what? !
This guy thought way over 100 years ahead! - He decided to push hot air in ! ..... as opposed to what we had drummed into our heads (ie that cold air at the inlet was the way to go!) - how could we be so wrong? :facepalm: ....... so there! :msn-wink:

[ceci]

Ceci
Pretty sure Ken Seeber would know something about that, he worked for the company which invented and developed that system. (Orbital Australia).

:

Thank you very much WilDun, you already mentioned it to me previously that Ken worked in Orbital and he already clarified some things for me.
Orbital uses the piston compressor only to create the layered charge, discard the supercharger option.
In the compressor model for mopeds it is logical that it be used only for that function, but the compressor model used for UAVs can be oversized and used for supercharging as well.

[WilDun]

Thank you very much WilDun, you already mentioned it to me previously that Ken worked in Orbital and he already clarified some things for me.
Orbital uses the piston compressor only to create the layered charge, discard the supercharger option.
In the compressor model for mopeds it is logical that it be used only for that function, but the compressor model used for UAVs can be oversized and used for supercharging as well.

Yes it's good to hear Ken was discussing it with you! ...... and then one thing leads to another ...... that's development !

[WilDun]

There are several advantages to piston compressors. First, they can be used to balance the engine. Second their delivery is pulsed and can be timed to arrive at the cylinder at the right time. One of the very first two strokes took advantage of all this in 1878.

Lohring Miller

The path of the crankpin (compressor piston) is interesting - but I don't understand the 'stepped' part of the piston! - (crosshead?).




Which came first? - Did somebody copy someone else? ......... probably Harry Ricardo improved it!

Clerks 345809 Ricardo Dolphin345810

[ceci]

Yes it's good to hear Ken was discussing it with you! ...... and then one thing leads to another ...... that's development !

Listening to Ken is always enriching.
Piston pump supercharging through the crankcase is an option that can improve results on your UHV project.
As there is no cylinder fill time diagram (the pressure on the sheets determines the time), it is a function of pumping the load

[WilDun]

Listening to Ken is always enriching.
Piston pump supercharging through the crankcase is an option that can improve results on your UHV project.
As there is no cylinder fill time diagram (the pressure on the sheets determines the time), it is a function of pumping the load

Sorry, I assume that when you say "sheets" you mean reeds (as in reed valves)?

I don't have a project at the moment! - I just talk!! :laugh:

[ceci]

Sorry, I assume that when you say "sheets" you mean reeds (as in reed valves)?

I don't have a project at the moment! - I just talk!! :laugh:



That is what "reeds" meant.
Ken's UHV project is a rough diamond that is about to be polished, but it is a great diamond of immense value

[WilDun]

That is what "reeds" meant.
Ken's UHV project is a rough diamond that is about to be polished, but it is a great diamond of immense value

Yes, he's just starting out on his project and I'm keen to see how it pans out later on!

[lohring]

"Which came first? - Did somebody copy someone else? ......... probably Harry Ricardo improved it!"

All the way up to the Rolls Royce Crecy, the king of supercharged two strokes. Doesn't the combustion chamber look familiar?

Lohring Miller

345812

[WilDun]

"Which came first? - Did somebody copy someone else? ......... probably Harry Ricardo improved it!"

All the way up to the Rolls Royce Crecy, the king of supercharged two strokes. Doesn't the combustion chamber look familiar?

Lohring Miller



I believe that combustion chamber was a Ricardo design - I can remember that in the late fifties, Deutz (I think) were using it in their diesel engines.
Not so sure the Crecy was ever the king - it was being groomed to become king but never got there, the end of the war being the end of its chances! (along with the Napier two stroke engines and others) - ie when jet engines invaded.

[WilDun]

Has anyone ever heard any worthwhile reports on the (HCCI) Mazda 3 engine? - probably been on the market 6 months by now!
I was very interested in that, but it doesn't really seem to have hit the news with any great impact (is that good or bad? - no news is good news maybe?).

Found something -

https://www.youtube.com/watch?v=PT2Mt-tkJ_4

https://www.youtube.com/watch?v=yNSxow3W7ek

https://www.youtube.com/watch?v=vEMuOi0N2fQ

[husaberg]

I have posted some stuff on this engne befire but i thing this one has some extra that might interest Neil
345860

[ken seeber]

I have posted some stuff on this engne befire but i thing this one has some extra that might interest Neil
345860

He's using a Tee Square, just how old is this ?

Anyways, it must be bullshit, he doesn't have glasses....:clap:

[WilDun]

He's using a Tee Square, just how old is this ?

Anyways, it must be bullshit, he doesn't have glasses....:clap:

Did you mean "pigshit" Ken? - don't think he needed glasses for the photo anyway, And the square? - that's to go with the drawing board! All very interesting though and I'm sure Neil will be very interested too!
Done mostly in the nineties and that article may have been written around 2010 (I think).

[Flettner]

yes very intetesting but I see they dont use an open ended sleeve like Riccardo, Ha Ha and me.

[husaberg]

yes very intetesting but I see they dont use an open ended sleeve like Riccardo, Ha Ha and me.

Did you see what he mussed about the motion of the sleeve, that the bit i was curious about.

link to the other one i posted
https://www.kiwibiker.co.nz/forums/showthread.php/171300-Oddball-engines-and-prototypes?p=1131056224#post1131056224


It came from Rob Collet who made comparativley more HP/litre and came much later, if you take away the effect of the blower as well.
331871331868331870331869
this is the sleeve drive he has although his is adjustable

https://www.youtube.com/watch?v=D-IhNsalWbI


https://www.youtube.com/watch?v=pNrWaKofEdA
https://www.youtube.com/watch?v=bQSwD9zvkaE
when he says the issues with the piston shrouding the port this is what he means
buggar can't find the pic

[WilDun]

Did you see what he mussed about the motion of the sleeve, that the bit i was curious about.

link to the other one i posted
https://www.kiwibiker.co.nz/forums/showthread.php/171300-Oddball-engines-and-prototypes?p=1131056224#post1131056224
Yes the article in your post, says he just made the sleeve reciprocating instead of oscillating (as in the Bristol engine). He says that with modern oils there was no need for oscillating motion anymore (originally needed to spread the oil over the surface of the sleeve).
Main problem is, if that arrangement is used in a two stroke, the sleeve is a mighty heavy piece of metal to be bobbing up and down (thinwall or not) at crankshaft revs!
---------------------------------------------------------------------------------------------

Here is an interesting piece of (two stroke) engineering from Poland (with a "Neil " type? sleeve/piston arrangement)

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The crank arrangement seems to have been inspired by this Esso experimental design (no conrods) :-

345867

Sorta mesmerising! :blink:

[lohring]

The top of an open ended sleeve is exposed to the full combustion pressure. It acts just like an extra piston with a small area and shorter stroke than the main piston. This probably at least makes up for any extra drag.

Lohring Miller

[WilDun]

The top of an open ended sleeve is exposed to the full combustion pressure. It acts just like an extra piston with a small area and shorter stroke than the main piston. This probably at least makes up for any extra drag.

Lohring Miller

Are you referring to the Polish engine?
The sleeve in this design would probably be considered the piston (if only because it reciprocates and acts on the crank), but also the inner part with piston rings and what looks like an "Orbital" type injector, should probably be considered a static piston.
So because of this static piston, the sleeve/piston isn't actually open ended any more and therefore is separated from combustion pressure - the top end area you mention (with an extended diameter) can then become a piston for a compressor/blower or a supercharger (depending on the diameter used.)

I'm quite keen on that piston/crank arrangement too - but the design and layout of this engine does look slightly awkward in a motorcycle!

I could of course be wrong but that's how I see it! :rolleyes:

[lohring]

It doesn't look like that would be true for any sleeve valve that uses rings for the top seal. However, the piston's rings will tend to drag the sleeve along with the piston. I think the friction loss of sleeve valves is actually smaller than poppet valve trains, but I'm not aware of actual tests.

Lohring Miller

[WilDun]

It doesn't look like that would be true for any sleeve valve that uses rings for the top seal. However, the piston's rings will tend to drag the sleeve along with the piston. I think the friction loss of sleeve valves is actually smaller than poppet valve trains, but I'm not aware of actual tests.

Lohring Miller

When it comes to using the sleeve with extended top diameter as a (relatively speaking) low pressure compressor - I feel that it may not need to have totally positive displacement in this case and so it might not have to run snugly (or even touch) the inside walls of the cylinder! (ie the upper extended diameter part of the cylinder) or am I missing the point? - but what do you think?

This is just a schematic for the cycle in one cylinder of the engine from Poland we are discussing. :-
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[lohring]

Once again, I think simpler is better. The sleeve is hard enough to make good enough to seal only the cylinder well. The Bristol spent a lot of time getting their four stroke sleeves good enough. No one else has done it recently in a production engine as far as I know. An even simpler uniflow engine is the double piston design. It has had several successful production versions. The only complication is the double crankshaft. Otherwise, it doesn't suffer from many of the other uniflow engine faults. I just don't see anyone putting the required serious development money into any new IC engine.

Lohring Miller

[WilDun]

Once again, I think simpler is better. The sleeve is hard enough to make good enough to seal only the cylinder well. The Bristol spent a lot of time getting their four stroke sleeves good enough. No one else has done it recently in a production engine as far as I know. An even simpler uniflow engine is the double piston design. It has had several successful production versions. The only complication is the double crankshaft. Otherwise, it doesn't suffer from many of the other uniflow engine faults. I just don't see anyone putting the required serious development money into any new IC engine.

Lohring Miller
No you're right, the days of any real breakthrough inventions in this field are over I guess and if I were a manufacturer I wouldn't try to change!

Yes the opposed piston, uniflow scavenged engine offers a lot and is my favourite.
I do also believe that this design offers a lot too, especially with its crank operation - the cylinder also resembles the RR Crecy (in some ways) and as such, would lend itself to uniflow operation, instead of the traditional Schneurle scavenging!

Schneurle was fine for the last 80 years or so, but was also the root of all evil! - why did we do it? :facepalm:

[lohring]

You get a lot better piston and combustion chamber shape with the Schnuerle system than outboard style cross flow designs. The only alternative cross flow design with promise was the QUB cross flow design. The uniflow designs also have reasonable combustion chamber shapes. Below are some sketches that give you an idea of the issues. I think the development work by Gordon Blair sponsored by Yahama did a lot to refine the current 5 transfer engines.

Lohring Miller
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[WilDun]

Gordon Blair did a lot of research for Yamaha etc. and as well as his two stroke work he also did a lot of research on four stroke cylinder head design - eg the Toyota 4 valve heads (which were I believe made by Yamaha).

Dr Blair was a big fan of the two stroke and dedicated to improving the existing Schneurle system but significantly, he didn't forget the four stroke (his main bread and butter!).
(BTW he lived and worked only a few miles from where I grew up).

When I said that the Schneurle system has done its dash, I meant that, although commercially viable and reasonably successful for quite a while, the whole design needs to be replaced by something which almost eliminates a fresh, oil laden charge from coming into contact with the outgoing charge either in the cylinder or in the exhaust pipe - that really was the cause of its demise on the road going machinery.
The two main things which can save it are its power to weight ratio, a clean exhaust and the possibility of simplicity, that is the only chance it will ever have in making it back on the roads. - The opposed piston is a distinct possibility here - as for combustion chamber shape, could HCCI take care of that concern? and at the same time get rid of all our 'squish' woes (doesn't really matter about the shape anymore)?

Here I go again! Gordon Blair would turn in his grave if he heard me! - so I'll shut up and if someone steps up and proves me wrong, then, so be it! :rolleyes:

[lohring]

I think the big Etec engines are as close as modern two strokes come to your ideal. The combination of a simple basic design with fuel and oil injection and a variable length pipe all controlled by modern electronics works well. Carefully controlled oil injection seems to be able to reduce oil consumption to 4 stroke levels. I don't know if similar engines could be developed for road use. The operating conditions are very different. Orbital tried, but their success has been limited as far as I know.

Lohring Miller

[WilDun]

I think the big Etec engines are as close as modern two strokes come to your ideal. The combination of a simple basic design with fuel and oil injection and a variable length pipe all controlled by modern electronics works well. Carefully controlled oil injection seems to be able to reduce oil consumption to 4 stroke levels. I don't know if similar engines could be developed for road use. The operating conditions are very different. Orbital tried, but their success has been limited as far as I know.

Lohring Miller

Too risky for any manufacturer to make big changes in these uncertain times when the fickle customers are more concerned with fashion and fantasy than engineering excellence and innovation!.......... But let's keep plugging on - this stuff to me is much more exciting than any thriller on TV! ........ How the hell could crime be more fascinating than this!

[Frits Overmars]

... this stuff to me is much more exciting than any thriller on TV! ........ How the hell could crime be more fascinating than this!What's next Will? Trying to steal a bike? I hereby deny that I ever said: "You must ride a two-stroke as if you just stole it".:msn-wink:

[WilDun]

Yes, well, that could not possibly happen because there wouldn't be a two stroke to steal in the first place and if there was, the thieving dickheads wouldn't bother stealing it anyway!

[WilDun]

Such is the state of affairs in regard to two strokes today!............. (BTW I'm away from home at the moment so, reduced to using my phone - we have just been released from house arrest!).

[husaberg]

Gordon Blair did a lot of research for Yamaha etc. and as well as his two stroke work he also did a lot of research on four stroke cylinder head design - eg the Toyota 4 valve heads (which were I believe made by Yamaha).

Dr Blair was a big fan of the two stroke and dedicated to improving the existing Schneurle system but significantly, he didn't forget the four stroke (his main bread and butter!).
(BTW he lived and worked only a few miles from where I grew up).

When I said that the Schneurle system has done its dash, I meant that, although commercially viable and reasonably successful for quite a while, the whole design needs to be replaced by something which almost eliminates a fresh, oil laden charge from coming into contact with the outgoing charge either in the cylinder or in the exhaust pipe - that really was the cause of its demise on the road going machinery.
The two main things which can save it are its power to weight ratio, a clean exhaust and the possibility of simplicity, that is the only chance it will ever have in making it back on the roads. - The opposed piston is a distinct possibility here - as for combustion chamber shape, could HCCI take care of that concern? and at the same time get rid of all our 'squish' woes (doesn't really matter about the shape anymore)?

Here I go again! Gordon Blair would turn in his grave if he heard me! - so I'll shut up and if someone steps up and proves me wrong, then, so be it! :rolleyes:

I did a reply to you the other day but it was lost
my understanding was Yamaha designed the TOyota GT2000 head even theough they had not made a bike bigger then a 350 2 stroke
it want that well they copied it back to do the XS650 a few years later
they went on to collaborate more with Yamaha and likely still do
the lead guy on the GT2000 and XS650 was the lead on the 5 valve and deltabox.
Yamaha it turns out never had a computer so they used to use the computer the Yamaha piano/Organ section had at night.
http://www.xs650.fi/pohja_files/en/truestory.htm
https://global.yamaha-motor.com/about/history/stories/0012.html
https://global.yamaha-motor.com/about/design/motordesign-history/history/from1965/

[WilDun]

I believe that G Blair did work for Yamaha when they were producing the four valve TX 500 twin and Toyota were developing the four cylinder1600 four valve head imodels in the mid eighties - this was well after the 6 cylinder models.

[ken seeber]

A 2 stroke...….no smoke and no expansion chamber


https://www.facebook.com/StrangeDevelopmentAndDesign/videos/277816313608614/

[WilDun]

A 2 stroke...….no smoke and no expansion chamber
https://www.facebook.com/StrangeDevelopmentAndDesign/videos/277816313608614/

Ken,
The video doesn't tell you much of course, but I guess they are on the right track, especially if the expansion chambers are not there mixing fresh charge and exhaust gas!
So as I see it, I may have been on the right track after all!
However before jumping with joy, we haven't as yet seen the result of the tests or know if we are getting adequate power or economy for the everyday two stroke!
It'll be interesting to see what transpires (hopefully soon), because it is getting towards the last chance for the two stroke to regain it's place on the roads!

[Frits Overmars]

A 2 stroke...….no smoke and no expansion chamber
https://www.facebook.com/StrangeDevelopmentAndDesign/videos/277816313608614/
Ken, The video doesn't tell you much of course, but I guess they are on the right track, especially if the expansion chambers are not there mixing fresh charge and exhaust gas! So as I see it, I may have been on the right track after all! However before jumping with joy, we haven't as yet seen the result of the tests or know if we are getting adequate power or economy for the everyday two stroke! It'll be interesting to see what transpires (hopefully soon), because it is getting towards the last chance for the two stroke to regain it's place on the roads!It took some digging because the 'info' mainly consists of boasting, but I found out that they use four-stroke-like cases and crankshaft, a mechanical blower, piston-controlled exhaust and transfer ports and a rotary exhaust valve that turns the symmetrical exhaust timing into asymmetrical, giving the supercharger a chance to supercharge the cylinder. Claim for their 600 cc parallel-twin is 200 hp, which I think is feasible with asymmetrical exhaust timing and supercharging.
It reminds me of a similar project, started by my mate Roland Holzner, a couple of years ago.
Don't let the 'Turbo'-text on the engine fool you. It's a crankshaft-driven centrifugal supercharger, but as Roland said: "If it doesn't say Turbo, it won't sell".
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[Grumph]

I believe that G Blair did work for Yamaha when they were producing the four valve TX 500 twin and Toyota were developing the four cylinder1600 four valve head imodels in the mid eighties - this was well after the 6 cylinder models.

I don't think he was involved in the early 4V heads - but he was certainly involved with the 5 valve ones.

He gave a talk here in ChCh for the NZ Engine Reconditioners assn - they liked to have a feature speaker for the annual conference.
He was on his way home to the UK from Japan where he'd been showing Toyota/Yamaha and Nissan current thoughts on 4v design.
I'm pretty sure that it was while he was there Yamaha decided to let the 5v engines run their time and concentrate on the next gen of 4V ones.

I got to ask one question - related to the advance curve for the 5v engines - which is just plain weird.
He confirmed it was a turbulence problem - and dropped a pretty plain hint the 5V days were numbered
Incidentally, as I've said before elsewhere, the only bike guys there were the Britten team - and me.

Frits - good to see you posting - hope all's well.
That blown engine could well be a minefield when it comes to cooling. Everything would need to be water jacketed at that power level. Blower, manifolding, driver's gonads....

[WilDun]

I don't think he was involved in the early 4V heads - but he was certainly involved with the 5 valve ones.

He gave a talk here in ChCh for the NZ Engine Reconditioners assn ..........
I'm pretty sure that it was while he was there Yamaha decided to let the 5v engines run their time and concentrate on the next gen of 4V ones.............
He confirmed it was a turbulence problem - and dropped a pretty plain hint the 5V days were numbered ..........

That blown engine could well be a minefield when it comes to cooling. Everything would need to be water jacketed at that power level. Blower, manifolding, driver's gonads....

Yeah, the 5 valve engines didn't quite get there and I guess by what you are saying, he didn't have his heart in it anymore - but, was it his invention or was he was charged with the task of trying to develop it for Yamaha? (I dunno) - certainly it agrees with Frits's 'KISS' principle!
As for the "gonads" thing - mightn't be a bad idea for some of the clowns riding around the roads - by turning them into "Eunuchs" and save the world from the proliferation of such people in society! ..... me? - I somehow escaped! :rolleyes:

FRITS
Thanks for all the digging you have been doing - you obviously are still interested in the future of the two stroke as a viable powerplant for everyone in tomorrow's (post pandemic) world, as opposed to competition only.

As I have been saying, competition is often a spinoff from whatever we are used to driving on the roads and if the interest swings to competing with EV's (and it could if fashion dictates) then where will the two stroke with it's versatility end up ? - in the history books!
I still maintain that a "clean" two stroke has a future in the 'hybrid" scene and there could be a huge market in the underdeveloped - I mean emerging countries - (got to be PC! :facepalm:) or anyone in the world looking for independent personal transport.

Your old Mate is right, the name needs to titivate the simple minds of the 'dedicated followers of fashion' (these people with their disposable income are everywhere).
The name tag is all important and keeps changing - eg our original (and correct) idea of a "moped" no longer bears any resemblance to what people are calling mopeds today! ..... so maybe we could invent a new name for the supercharger (to keep it separate from a turbocharger) ......... maybe "Grunter" - or something equally ridiculous!

[190mech]

I looked at the Strange vid,,appears to have the spark plug lead attached to the supercharger housing,and a UNI filter bobbing around on the "cylinder head"..How do we know if the electric starter isnt motoring that 'engine' over to make it appear to be running??Seems to 'run' rough also..Perhaps I'm a skeptic,but after the Ryger affair more proof will be needed!:msn-wink:

[WilDun]

I looked at the Strange vid,,appears to have the spark plug lead attached to the supercharger housing,and a UNI filter bobbing around on the "cylinder head"..How do we know if the electric starter isnt motoring that 'engine' over to make it appear to be running??Seems to 'run' rough also..Perhaps I'm a skeptic,but after the Ryger affair more proof will be needed!:msn-wink:

There is the old English saying, "the proof of the pudding is in the eating"! :yes:

[husaberg]

Yeah, the 5 valve engines didn't quite get there and I guess by what you are saying, he didn't have his heart in it anymore - but, was it his invention or was he was charged with the task of trying to develop it for Yamaha? (I dunno) - certainly it agrees with Frits's 'KISS' principle!
As for the "gonads" thing - mightn't be a bad idea for some of the clowns riding around the roads - by turning them into "Eunuchs" and save the world from the proliferation of such people in society! ..... me? - I somehow escaped! :rolleyes:



https://www.kiwibiker.co.nz/forums/album.php?albumid=4977

[ceci]

A 2 stroke...….no smoke and no expansion chamber


https://www.facebook.com/StrangeDevelopmentAndDesign/videos/277816313608614/


This video is a screenshot of the one shown on the creator page.


https://www.youtube.com/watch?v=ZhqFbFGP5hs

The other:University Of Idaho Clean Snowmobile Team's Rotary Synchronous Charge Trapping. Valve system blocks exhaust port to prevent fresh intake charge from going into exhaust.


https://www.youtube.com/watch?v=fiJKeyHk-II

[lohring]

Someone needs to explain to me why these complex new designs are better than the simple, tuned pipe, crankcase scavenged engines. Are they more powerful, easier to maintain, less expensive, or lighter weight? They may be more compact and have a better power band, but I can't think of any compelling reason to chose this new design or any others for small engines.

Lohring Miller

[WilDun]

Someone needs to explain to me why these complex new designs are better than the simple, tuned pipe, crankcase scavenged engines. Are they more powerful, easier to maintain, less expensive, or lighter weight? They may be more compact and have a better power band, but I can't think of any compelling reason to chose this new design or any others for small engines.

Lohring Miller

Lohring,
I agree that the two stroke with it's (inherent) simplicity and great power/weight ratio is being undermined by the need to add on all sorts of attachments in order to make it perform properly all over the rev range (this being very necessary on road machines), the tuned pipe has it's (often huge) advantage in the BHP department but only in within a certain rev band - all the other addons/accessories are there to make up for it's downsides on the roads where the full rev range is important - so we still haven't got any simple answer to making the two stroke useful for commuting or cruising on highways! - but the bloody oily smoky exhaust which has more or less sunk it as far as using it for something other than 'sport' or garden tools etc. is still with us - that alone could cause its demise!

That's my take anyway - we are proposing all these 'new' ideas only because it gives us pleasure to keep trying something new - as you say, no compelling reason!
Then, (to put the boot in), it appears that governments are looking at banning all combustion engines eventually, possibly by as early as 2030!
I'll probably be gone by then - (think I was doomed to live only in the internal combustion era !). :scooter: :mad: - look at the pollution coming out of that thing! - and to think that I lived through that! ......... but, it was a “fun ride” while it lasted!

[ken seeber]

While on the ongoing & possibly never ending adventure of understanding 2 strokes, I remember the Borgward. Here's a nice read:

https://wartburg353knight.blogspot.com/2011/11/goliath-story-must-for-two-stroke-fans.html

[WilDun]

While on the ongoing & possibly never ending adventure of understanding 2 strokes, I remember the Borgward. Here's a nice read:

https://wartburg353knight.blogspot.com/2011/11/goliath-story-must-for-two-stroke-fans.html
A very interesting story Ken!
That Goliath sports car was a beautiful piece of work! Also, why didn't the world take notice of that fuel injected two stroke?
Fuel injection (as in the Daimler Benz V12 engine ) was obviously successful since before WW2, however hasn't really been seen at all in two strokes till the Skidoo and Outboard guys got it working!
I know that Orbital (in another form) did get it sussed, BTW what happened to that? - and of course, our own Flettner did it successfully (in yet another form) on his Kawasaki Bighorn - which is still going strong I believe! - If only they (manufacturers) would take more notice of his efforts and experience in developing this and listen to him, it might just have a chance of saving the two stroke for a while!

[ken seeber]

I always thought there was something fishy about 4 strokes....here's proof..:nya::nya:

https://www.facebook.com/skillvdo/videos/685716632262283/

[pete376403]

Long read but note the bit about the Kawasaki powered race car: https://www.linkedin.com/pulse/business-development-build-race-car-consultant-vp-jeff-krause/?fbclid=IwAR02Gup3SRQWMnRMSf3624Bze5YHQzCTxBcBsDH5 La41Zz38RavIp2DikaY

[WilDun]

I always thought there was something fishy about 4 strokes....here's proof..:nya::nya:

https://www.facebook.com/skillvdo/videos/685716632262283/

That's a bloody good idea Ken - instant smoked fish - might be better to use some oil from a tree or somewhere though! -at least there will always be some use for a crapped out four stroke, but I thought that it was only supposed to be two strokes that smoked!

Pete, - Why didn't Kawasaki ever get into car production I wonder?

[ceci]

Hello everyone.
I wonder if this already exists?
I'm not interested in opposite piston engines, just curious

[WilDun]

Hello everyone.
I wonder if this already exists?
I'm not interested in opposite piston engines, just curious

It does seem a little unnecessary, ie when you can have uniflow without the need for "twin piston" type of arrangement. as well. - I've never seen the "twin piston" format used in this way.

[Frits Overmars]

It does seem a little unnecessary when you can have uniflow without the need for "twin piston" type of arrangement. as well.My thoughts exactly. But I seem to remember that Flettners first uniflow engine had more or less the same layout, apart from the master-and-slave con rods.
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[WilDun]

My thoughts exactly. But I seem to remember that Flettners first uniflow engine had more or less the same layout, apart from the master-and-slave con rods.
346197

I never knew that fact! (ie about the Flettner machine). Well I guess that he has moved on a little by now and has eliminated that side street as the best route to progress!

[ceci]

Thank you all
I was curious as there are so many new prototypes on the Uniflow topic

https://hackaday.io/project/10670-open-source-two-stroke-diesel-engine

https://motore-a-pistoni-solidali-due-tempi3.webnode.it/#

[WilDun]

Thank you all
I was curious as there are so many new prototypes on the Uniflow topic

https://hackaday.io/project/10670-open-source-two-stroke-diesel-engine

https://motore-a-pistoni-solidali-due-tempi3.webnode.it/#

I think that the (most developed) OP engine on the horizon is the American "Achates" who openly admit that the inspiration for their engine came from the pre WW2 design from Junkers - it's a two stroke (admittedly a diesel) but a lot of research has gone into it and no doubt a lot of dollars!
I believe that the Cummins Truck empire is now involved with Achates and I don't think that they would be there if it didn't stand some chance of success, some OP engines have already been successful in the past - some prefer only one crank and others two cranks....... there are others (individuals and companies) checking all this out as well!

[pete376403]

I think that the (most developed) OP engine on the horizon is the American "Achates" who openly admit that the inspiration for their engine came from the pre WW2 design from Junkers - it's a two stroke (admittedly a diesel) but a lot of research has gone into it and no doubt a lot of dollars!
I believe that the Cummins Truck empire is now involved with Achates and I don't think that they would be there if it didn't stand some chance of success, some OP engines have already been successful in the past - some prefer only one crank and others two cranks....... there are others (individuals and companies) checking all this out as well!

Cummins should "re-invent" the TS3 and TS4 Rootes engine that they killed off so long ago in favour of their own designs.

[Flettner]

Thank you all
I was curious as there are so many new prototypes on the Uniflow topic

https://hackaday.io/project/10670-open-source-two-stroke-diesel-engine

https://motore-a-pistoni-solidali-due-tempi3.webnode.it/#

The little buggers are everywhere. This one will run on E85. 175cc, single cylinder.
And yes Frits, my Uniflow engines to date are essentially two split singles head to head, well, heads removed.

[WilDun]

Cummins should "re-invent" the TS3 and TS4 Rootes engine that they killed off so long ago in favour of their own designs.

Yes Pete, they should, but will they?

This world is ruled by the rich and powerful, (which could probably also describe some of Cummins top brass!) - most of them probably have no idea or care whether or not it's a two stroke that is powering their superyacht!

[lohring]

Here's your dream supercharged two stroke.

http://strangedevelopment.com/

Lohring Miller

[husaberg]

Here's your dream supercharged two stroke.

http://strangedevelopment.com/

Lohring Miller

Coates has been trying to get a rotary Exhaust valve reliable since the 1980's.
http://www.coatesengine.com/csrv-system.html

https://www.youtube.com/watch?v=u4icAiZp7l8

https://www.youtube.com/watch?v=vjHkAgi9TbY

https://www.cycleworld.com/2014/01/17/ask-kevin-do-rotating-spherical-valves-have-a-future-in-motorcycling/

[lohring]

And unlike poppet valves, rotary valves in all their configurations leak. However, that may not matter as much as an auxiliary exhaust valve in a two stroke. It only needs to withstand the boost pressure before the piston closes the main exhaust port. Still, I can't imagine that that's a better configuration than the turbo systems modern snow mobile engines use.

Lohring Miller

[Frits Overmars]

... rotary valves in all their configurations leak. However, that may not matter as much as an auxiliary exhaust valve in a two stroke. It only needs to withstand the boost pressure before the piston closes the main exhaust port. Still, I can't imagine that that's a better configuration than the turbo systems modern snow mobile engines use.Those snowmobile turbos only blow into the crankcase and from there on everthing is conventional, with exhaust ports that close after the transfers, so the cylinders cannot be supercharged through the transfers.
The rotary drum in the Strange Development engine closes the exhaust ducts before the pistons close the transfer ports, so this engine can be supercharged.

[WilDun]

Those snowmobile turbos only blow into the crankcase and from there on everthing is conventional, with exhaust ports that close after the transfers, so the cylinders cannot be supercharged through the transfers.

So I guess that's why they still use chambers?


The rotary drum in the Strange Development engine closes the exhaust ducts before the pistons close the transfer ports, so this engine can be supercharged.

As usual, I have probably missed something - is there a good drawing around somewhere which illustrates this?

[Pursang]

https://www.mahle-powertrain.com/en/experience/mahle-jet-ignition/

Frits, or Wobbly, to your knowledge, has this (or competitors similar systems) ever been trialed in a two-stroke engine? Seems it would bring similar benefits as in a four stroke.

Solutions to the IC engine problems are Not all mechanical ones. If we are interested in "efficient combustion" this idea has Merit.

A clever Mahle Engineer may have read the following notes?? You Decide! I guess a Modernised 'update' of a 90year old invention could be granted a patent.

Here are some notes from Robert Harris, aka 'Bob the Computer Guy' from an ancient DIY FI notice board.
I like his Stream of Consciousness communication style, but it often takes several reads (even some meditation)to see the Gold.

Date: Thu, 06 Apr 2000 21:12:03 -0700
From: Robert Harris
Subject: Antiquity

Goals
Always drive the mixture towards lean best torque/power
Remain at light knock as long as possible
Run as close to unthrottled ( diesel like ) as possible
Use the highest intake temperature possible to accomplish this within the oxygen budget

Now we hard dive and snatch a gem from the ancient unenlightened ones.

Packard - 1930ish - depression days when Packard was big time luxury player

Reference: Dykes Pg 108, Instruction 13 Pg 140, Instruction 14 DrD - you really have to get one - its the pure motherload!!!

Fuelizer

Now those poor old bastards had to make an engine idle with a coin balanced on the head and pull from idle to whatever and be glass smooth at the same time.
Hard starting and rough cold idle offended the patrons mightily.

Packard's approach was straight out of the darkside. No choke - no passive anything. By god, they got right down to it and ACTIVELY heated the intake charge from cranking on.
Got it hot and dry ( fully vaporized ) and actively kept it that way. No pucking around for dem.

"Purpose: The fuelizer heats the gasoline and the air from the carburetor, so that the mixture enters the cylinder as a dry gas rather than a combination of
air and liquid particles."

What they did was shunt some intake charge after the carb into a small combustion chamber, light it with a spark and vent the hot exhaust straight back into the intake charge. And since the chamber was in direct contact and part of the intake manifold, virtually all of this heat went into the charge.
Get right to it and get it done.

Yikes. But wait - worst case was about 3% of the fuel used. (5% for Mahle) So how much do you waste cold "choked" start, idle, warmup, high vacuum light cruise ??
Because this was thru a tiny passage, as the flow increased, less was diverted thru the shunt as the rpm, load, temperature increased and was cut off at about 30 mph.
Self adjusting. Plug was more like a jet engine ignitor than a sparking plug. And since it was venting back into the charge via "long" tiny ports, the flame was quenched - leaving nothing but energy in the form of heat.

So what does this buy us? Start with pre-burning a small amount of fuel and using that to heat the air and vaporize the fuel downstream. No liquid gasoline combustion.
Straight homogeneous pre-mixed gas. Very smooth, very efficient, almost perfect combustion that left no deposits from crap gas.

The exhaust was jetted thru tiny passages that killed the flame so that only hot gas below the ignition temperature of the main charge entered the charge.

Had a sight glass to optimize the color - thus efficiency of the combustion -does ccd optics or colortune for the fuelizor click on anything?

Now we know that we want the highest temperature charge possible under less than wot because that means we minimize the pumping and throttling loss's.
Anyone care to guess how much this "superheating" of the air did for reducing those losses at the time they are the greatest. Plus no low temperature oil dilution, no pinging carbon buildup. Since it worked on a very high end luxury car, might give us a clue that everything else might have been a lessor compromise.

What does this give us? How about a fuel efficient way of ACTIVELY changing the charge temperature to great benefit without screwing up high demand operations?

Fuel injection provides dry air - right? So, unlike Packard, we run dry air into the fuelizor and "inject" a desired amount of fuel to get the charge air heating we want. Now within reason we can computer control the amount of charge heating needed to optimize main combustion. And we can do what they couldn't and stratified charge is attempting.

Run the fuelizor rich. Controlled Pig rich. The excess fuel is exhausted into the intake manifold not as gasoline, but CH4, CO and H2. Nice high energy gaseous fuels that really help meet our goal of a premixed gas thru most of the power band. And any remaining liquid is boiled, vaporized and greatly refining into much smaller chain components.
The heat is not wasted either - remember pumping losses. And for the knock o phobic - twice the amount of fuel consumed is released as CO2 ( definitely changes knock ) and H2O - water injection - to the tune of about twice the amount of water formed as gasoline consumed - with the kicker that its as steam - expanded ~ 1800 times liquid water - hot dry superheated steam. And what effect might that have on density downstream?

A touch of Glassman again. Peak Flame temperature is a product of three things only. The total atomic mass of all the components, the atomic distribution ratio of the components C H O N, and the total energy present and released ( fuel chemical ) during combustion. It's massively insensitive to pressure - that only changes the burn rate - not the temperature.
Virtually all of the heat consumed by the fuelizor is transferred to the intake charge which is then recovered at combustion. This implies that we recover in combustion virtually all of the heat "wasted" to condition the intake charge.
Plus, we waste much less energy on pumping losses. And we get much better faster efficient combustion when its most needed as a bonus.

GM tried unsuccessfully during the manufactured gas crisis of the seventies to twice burn the charge by intaking the exhaust of one cylinder, mix with same air and fuel and reburn. Efficiency went way up, but power bit the big one. History repeats 40 years after the Packard, but not done right. So we have major precedent for what I'm thinking.

Since flame speed is irrelevant - only quantity of gas, heat and desirable end products is, this opens Dave W's cherished back door. Suppose we introduced some gasocrap to the fuelizor. It would get converted to a much more useful fuel and not waste anything. Knock quality is irrelevant - we are not compressing it - just burning it, converting it to a higher quality fuel and recovering virtually all its energy. Remember virtually all of the waste heat is going into the air charge.

To further weird the wicked, you might want to check out the efficiency of conversion of chemical energy to work of an external combustion engine such as the Stirling.
Just might want to increase the percentage of fuel a tad over what Packard was using - specially since we can control it. (WOW! Mahle at 5%)
And a look at catalytic convertor material might allow us to increase the efficiency and heat even more.

The thought of greatly reduced pumping losses, refining crap liquid fuel into high quality gaseous fuel, nicely improved thermal and combustion efficiency in a region where it is not necessary to sacrifice efficiency to maximize and doing it with ancient technology ought to have your head spinning and the thought of continuously variable effective VE and compression ratio without moving some huge mass of metal around. And since the high temperature chargewill be much faster burning, throw in better pressure to mechanical energy conversion than normal - about the same as increasing the expansion ratio - without the complications.
And I only ran across this evening on browsing for something else. Welcome to my nightmare.


Date: Thu, 06 Apr 2000 21:43:20 -0700
From: Robert Harris
Subject: Antiquity - after thought.

Do not confuse the fuelizer with EGR.
EGR displaces some of the intake charge with residual exhaust, thus reducing the amount of oxygen and increasing the amount of combustion products in the
total charge prior to combustion

Fuelizer - precombusts part of the charge - but has no change on the total oxygen present in the charge nor the total combustion product from the charge.
All it is doing is pre-burning part of the charge and the remaining part of the charge will have approximately the same ratio of fuel to air as the total initial charge.

This is not to down EGR - I love the stuff - but to make sure you understand the difference.

The Fuelizer's unburned fuel is not discarded, but is available in a higher quality form for the remaining main charge - thus keeping close to the original mixture balance.

Got to do some more reading and writing - but major problem of rich combustion is that there is insufficient time for some of the products to release their energy in a timely fashion for conversion to pressure, but since we have much longer, that loss in efficiency of rich PARTIAL burn is not a problem.

This implies that the main charge will burn in the cylinder with little degradation over a normal charge, and will in many regions burn faster and better.


Phew! Cheers, Daryl.

[190mech]

I remember reading of Smokey Yunick's hot vapor engine;
https://www.legendarycollectorcars.com/featured-vehicles/other-feature-cars/smokey-yunicks-hot-vapor-fiero-51-mpg-and-0-60-in-less-than-6-seconds-see-and-hear-it-run-in-our-exclusive-video/
Again is heating the intake to allow better combustion..

[Pursang]

I remember reading of Smokey Yunick's hot vapor engine;
https://www.legendarycollectorcars.com/featured-vehicles/other-feature-cars/smokey-yunicks-hot-vapor-fiero-51-mpg-and-0-60-in-less-than-6-seconds-see-and-hear-it-run-in-our-exclusive-video/
Again is heating the intake to allow better combustion..

Yes Smokey is a Hero of mine! Practical & effective solutions to all sorts of problems..especially poorly written "Rules". ;)

Cheers, Daryl.

[lohring]

Those snowmobile turbos only blow into the crankcase and from there on everthing is conventional, with exhaust ports that close after the transfers, so the cylinders cannot be supercharged through the transfers.
The rotary drum in the Strange Development engine closes the exhaust ducts before the pistons close the transfer ports, so this engine can be supercharged.

I disagree. The turbo provides back pressure and the compressor raises the intake pressure. This runs the cycle as a whole at a higher pressure making more power. Some engines have gotten really serious with this and can make 800 hp with nitrous.

Lohring Miller

346363

[WilDun]

I disagree. The turbo provides back pressure and the compressor raises the intake pressure. This runs the cycle as a whole at a higher pressure making more power. Some engines have gotten really serious with this and can make 800 hp with nitrous.

Lohring Miller

Lohring, that photo is impressive but it also clearly illustrates the ridiculous amount of space being taken up by the chambers on a large capacity (ie cylinder capacity) two stroke! (maybe for better power of course, but can you imagine if they were not siamesed!). - ok certainly good for competition snowmobiles - not for bikes being used daily on the roads! - got to find a more compact and pollution free solution for them in order to realize the two stroke's potential and prolong it's time on this earth! ........ and it's a race between mankind and the two stroke (as to which will disappear first!).
:scratch:

[ken seeber]

Wow, just so much to comment on. Remember Dazza, that the 418, FJ thru to EJ grey engines (Holdens for those who aren’t aware of an Oz mfg GM owned car we had in Oz until GM killed it a couple of years ago) had that bimetallic flap in the exhaust that directed the hot exhaust to the underside of the closely bolted inlet manifold directly under the wonderful Stromberg carb.

Then, we had a period of wonderful gizmos that created a vortex in the fuel/air mix downstream of the carb that gave the usual 20% fuel savings.

I guess every country has had their share of wonderful devices. A few years ago were the HHO devices that turned water into energy. Gone.

I must be getting old.

One that I do hold a sort of hope for (other than some sort of smart 2 stroke) is the bottoming cycle, where essentially the waste heat is utilized. Remember, maybe a bit old now, is that 30% goes to power, 30% goes to coolant, 30% goes to exh and the remaining 10% to wherever. The bottoming cycle, as I remember it, utilized the higher grade of energy in the exhaust, a simple example could be to use an exhaust turbine to input to the output shaft.

Hydrogen. Dunno, just haven’t come to grips with the efficiency of production, the storage and the leakage (at molecular level).

As they say, “watch this space”…

[pete376403]

Wow, just so much to comment on. Remember Dazza, that the 418, FJ thru to EJ grey engines (Holdens for those who aren’t aware of an Oz mfg GM owned car we had in Oz until GM killed it a couple of years ago) had that bimetallic flap in the exhaust that directed the hot exhaust to the underside of the closely bolted inlet manifold directly under the wonderful Stromberg carb.

Then, we had a period of wonderful gizmos that created a vortex in the fuel/air mix downstream of the carb that gave the usual 20% fuel savings.

I guess every country has had their share of wonderful devices. A few years ago were the HHO devices that turned water into energy. Gone.

I must be getting old.

One that I do hold a sort of hope for (other than some sort of smart 2 stroke) is the bottoming cycle, where essentially the waste heat is utilized. Remember, maybe a bit old now, is that 30% goes to power, 30% goes to coolant, 30% goes to exh and the remaining 10% to wherever. The bottoming cycle, as I remember it, utilized the higher grade of energy in the exhaust, a simple example could be to use an exhaust turbine to input to the output shaft.

Hydrogen. Dunno, just haven’t come to grips with the efficiency of production, the storage and the leakage (at molecular level).

As they say, “watch this space”…

How could you not mention the energy polarizer? the magnetic device that "aligned the fuel molecules" or something ( and which also pretty much destroyed Brocks relationship with Holden)

[WilDun]

Solutions to the IC engine problems are Not all mechanical ones. If we are interested in "efficient combustion" this idea has Merit.

A clever Mahle Engineer may have read the following notes?? You Decide! I guess a Modernised 'update' of a 90year old invention could be granted a patent.

Here are some notes from Robert Harris, aka 'Bob the Computer Guy' from an ancient DIY FI notice board.
I like his Stream of Consciousness communication style, but it often takes several reads (even some meditation)to see the Gold ..............

Daryl, got time to sit down to read quickly through that - (I'm sure that both Mazda and Mahle have studied lots of stuff from the past ..... carefully!).
Very interesting stuff - I do remember reading about it before somewhere, but only glanced through it - and I've done that again ! - So next time I am going to sit and read it all again.
Just goes to show that we need to start going through all the "tailings" again and try to make use of the knowledge from the past by refining it!
- a lot can be learnt from the past!

[ken seeber]

How could you not mention the energy polarizer? the magnetic device that "aligned the fuel molecules" or something ( and which also pretty much destroyed Brocks relationship with Holden)

Would be too embarrassed...….:facepalm::facepalm:

On another note: https://motorbikewriter.com/aussie-2-stroke-engine-attracts-investor/ Watch this space.....

[WilDun]

.......... Then, we had a period of wonderful gizmos that created a vortex in the fuel/air mix downstream of the carb that gave the usual 20% fuel savings.

I guess every country has had their share of wonderful devices. A few years ago were the HHO devices that turned water into energy. Gone.

I must be getting old.

One that I do hold a sort of hope for (other than some sort of smart 2 stroke) is the bottoming cycle, where essentially the waste heat is utilized .................... As they say, “watch this space”…

Yes Ken,
All this stuff is still there somewhere, but if the results of those who worked hard to find improvements don't also improve the cashflow to the coffers of the rich and powerful, then it will be buried and forgotten, (rightly or wrongly).

[Pursang]

Wow, just so much to comment on. Remember Dazza, that the 418, FJ thru to EJ grey engines (Holdens for those who aren’t aware of an Oz mfg GM owned car we had in Oz until GM killed it a couple of years ago) had that bimetallic flap in the exhaust that directed the hot exhaust to the underside of the closely bolted inlet manifold directly under the wonderful Stromberg carb. Even the Model A had direct manifold heating, 'Hot box'. What What Packard did (and Mahle is redoing) was changing & improving the nature of the fuel, for operational & combustion efficiency from pre-start cranking and all part throttle use. As Bob said "everything else might have been a lessor compromise"

Then, we had a period of wonderful gizmos that created a vortex in the fuel/air mix downstream of the carb that gave the usual 20% fuel savings.
This was the purpose of the turbocharger in Smokey's 'Hot Vapour engine' Heat and agitate the mixture and maintain a +ve intake pressure, to minimise 'pumping losses'

I guess every country has had their share of wonderful devices. A few years ago were the HHO devices that turned water into energy. Gone.
Despite authenticated, observed demonstrations that frequency modulation can facilitate the cracking of H2O to 4xH & O2 the conventionally accepted process of electrolysis is considered the only 'scientific' way to achieve this and is therefore inefficient (re: Energy in vs Energy out).

I must be getting old. You're not Robinson Crusoe there!

One that I do hold a sort of hope for (other than some sort of smart 2 stroke) is the bottoming cycle, where essentially the waste heat is utilized. Remember, maybe a bit old now, is that 30% goes to power, 30% goes to coolant, 30% goes to exh and the remaining 10% to wherever. The bottoming cycle, as I remember it, utilized the higher grade of energy in the exhaust, a simple example could be to use an exhaust turbine to input to the output shaft.
The Adiabatic process does work see the 376-mpg-opel https://www.hemmings.com/stories/2007/05/01/big-oil-conspiracy-376-mpg-opel-uncovered

Hydrogen. Dunno, just haven’t come to grips with the efficiency of production, the storage and the leakage (at molecular level). Liquid storage reduces that, but raises it's own practical issues. Need to research it more in ICE applications.

As they say, “watch this space"… Looking forward to the Clean 2-Stroke Thread.

Cheers, Daryl

[Pursang]

Those snowmobile turbos only blow into the crankcase and from there on everthing is conventional, with exhaust ports that close after the transfers, so the cylinders cannot be supercharged through the transfers.
The rotary drum in the Strange Development engine closes the exhaust ducts before the pistons close the transfer ports, so this engine can be supercharged.


I disagree. The turbo provides back pressure and the compressor raises the intake pressure. This runs the cycle as a whole at a higher pressure making more power. Some engines have gotten really serious with this and can make 800 hp with nitrous.

For Max Power, don't worry about charge loss to the exhaust, run full power rich and burn it off in the turbo, a bit like they did in the old 'Fuel Dump' FI & Rally cars.:woohoo:

Not applicable to the "Clean 2-Stoke".

Cheers, Daryl

[WilDun]

Looking forward to the Clean 2-Stroke Thread.

Cheers, Daryl

Daryl, I find light blue and yellow print difficult to read, - try using dark blue and red if you can!

[Pursang]

Will, You need to go to the Dark Side!, things are clearer here :devil2:

Bottom Left of page!

Cheers, Daryl

[WilDun]

I've always been virtuous and caring person and have steered away from any "dark side" as much as possible! :innocent: ..... :rolleyes:
I must say that I have never found the dark zone here to be particularly enlightening! :no:

[Frits Overmars]

Daryl, I find light blue and yellow print difficult to read, - try using dark blue and red if you can!

Will, You need to go to the Dark Side!, things are clearer here

I've always been virtuous and caring person and have steered away from any "dark side" as much as possible! .....
I must say that I have never found the dark zone here to be particularly enlightering! Daryl, I checked with various experts. The pastor, the vicar, the rebbe and the imam insist that I keep away from people who want to lure me to the dark side, and the ophthalmologist advised me to skip the hard to read texts. I had already thought of the latter myself, so goodbye Daryl :devil2:

[WilDun]

Daryl, I checked with various experts. The pastor, the vicar, the rebbe and the imam insist that I keep away from people who want to lure me to the dark side, and the ophthalmologist advised me to skip the hard to read texts. I had already thought of the latter myself, so goodbye Daryl :devil2:

Unfortunately, the two stroke has capitulated and gone over to the dark side, lured there by the bright lights of the chance of becoming the star in competition, but now it has died and gone to hell! - what are we going to do about it? ........ it will have to be reincarnated :yes:

Just to go back a little and a good example of where the two stroke engine might be used - A twin cylinder MZ which once powered the Trabant (East German car) was fitted in a small aircraft - I think I mentioned this somewhere before .......
In this role it would run at a pretty much constant efficient speed and with the prop being the transmission, it can cope with its role whilst remaining a simple engine, .................................................. ...................................

Here is the Trabant engine in action (along with a common or garden B&S V twin version of the same aircraft!).
The MZ does fit in a very neat package and sounds very nice I must say! - the Briggs neither sounds nor looks quite as good (but it can fly on only 22 BHP! would you believe)!
https://www.youtube.com/watch?v=ZKOrmETgMkM

[WilDun]

Who would have thought that Shrek would have been interested in a two stroke? ! - a great, light hearted look at the two stroke! - very good!

https://www.youtube.com/watch?v=vB0TK0Gdmh4

https://www.youtube.com/watch?v=nYCzbGaXShM

[lohring]

I grew up on model two stroke engines. I've written some articles on the history of model racing engines. See namba.com/content/library/propwash/2018/october/14/ for that history.

Lohring Miller

[Niels Abildgaard]

Cummins should "re-invent" the TS3 and TS4 Rootes engine that they killed off so long ago in favour of their own designs.

The Rootes concept was stillborn from start.
The piston pin bearing has always(and still is ) been problematic for normal speed two strokes.
This is due to always being loaded in one direction and not fully rotating.
In a fourstroke piston pin is reversed loaded when piston is in top between exhaust and inlet.
Some oil seeps in and saves the day during compression/combustion.
A normal two stroke cylinder has one of these problematic bearings,a Rootes type cylinder has eight.

[WilDun]

The Rootes concept was stillborn from start.
The piston pin bearing has always(and still is ) been problematic for normal speed two strokes.
This is due to always being loaded in one direction and not fully rotating.
In a fourstroke piston pin is reversed loaded when piston is in top between exhaust and inlet.
Some oil seeps in and saves the day during compression/combustion.
A normal two stroke cylinder has one of these problematic bearings,a Rootes type cylinder has eight.


Neils - I have identified the bearings you are discussing (after a few confusing moments) and you may be correct. However to say that Rootes/Sultzer engine concept was 'stillborn' is maybe a little harsh! - Stillborn means they didn't get off the starting block, but these engines did and were popular for many years!
They were far from stillborn, in fact they were actually very successful - Yes when they were called 'the knocker', what you are describing was no doubt the reason for the characteristic 'knock'.

I have to admit they were quite noisy, although strangely, not inside the cab!
I saw them being used (and abused) in heavy duty service by the local quarry for many years, also they have been around for probably sixty years in some fishing boats!).
These engines were very fuel efficient, compact and were practically vibration free,

I can testify to all the things I described, especially to their lack of vibration.

[pete376403]

Neils - I have identified the bearings you are discussing (after a few confusing moments) and you may be correct. However to say that Rootes/Sultzer engine concept was 'stillborn' is maybe a little harsh! - Stillborn means they didn't get off the starting block, but these engines did and were popular for many years!
They were far from stillborn, in fact they were actually very successful - Yes when they were called 'the knocker', what you are describing was no doubt the reason for the characteristic 'knock'.

I have to admit they were quite noisy, although strangely, not inside the cab!
I saw them being used (and abused) in heavy duty service by the local quarry for many years, also they have been around for probably sixty years in some fishing boats!).
These engines were very fuel efficient, compact and were practically vibration free,

I can testify to all the things I described, especially to their lack of vibration.
No real problem, getting oil to the small end bearing. All of the shafts (crankshaft, rocker shafts) would have been plain bearings, pressure fed, so a jet / drilling at the side of the rod could squirt up under the piston, to lube the small end and cool the underside of the piston crown.

they seem to be lasting ok here "Over 60 years later - in 2015, about 20 of these old commercial fishing boats still go fishing each day, powered by their original Rootes-Lister TS3 marine engines. "

http://www.commer.co.nz/history

An d with regard to noise - http://www.commer.co.nz/history/ts3-engine-history

[WilDun]

http://www.commer.co.nz/history

And with regard to noise - http://www.commer.co.nz/history/ts3-engine-history

Well that sure clears up a few misconceptions!!:niceone:

[husaberg]

No real problem, getting oil to the small end bearing. All of the shafts (crankshaft, rocker shafts) would have been plain bearings, pressure fed, so a jet / drilling at the side of the rod could squirt up under the piston, to lube the small end and cool the underside of the piston crown.

they seem to be lasting ok here "Over 60 years later - in 2015, about 20 of these old commercial fishing boats still go fishing each day, powered by their original Rootes-Lister TS3 marine engines. "

http://www.commer.co.nz/history

An d with regard to noise - http://www.commer.co.nz/history/ts3-engine-history

Noise was never really the two strokes problem, they are very easy to quieten without losing performance, but its the frequency rather than outright Db that people assosicate with being noisey.
Whty is this the case People simply associate the higher frequencies as being more objectionable.

[WilDun]

Noise was never really the two strokes problem, they are very easy to quieten without losing performance, but its the frequency rather than outright Db that people assosicate with being noisey.
Why is this the case People simply associate the higher frequencies as being more objectionable.

Yeah but that's down to how it affects people and not everyone is the same - I normally like peace and quiet (also sometimes a two stroke in full song!) - some people would go mad with anything resembling either of those! - yet we're still all perfectly good people!

Big problem is, people tend to listen to other people and want to join in the sheep chorus - making things seem much worse than they actually are - this has been the tactics used by those looking for power from time immemorial! and even in our case, in the engine world, it is affecting the balance of power also (as it is intended to do).

A crowd without any individual thought and following an overpowering bullshit leader is rabble, who to my mind have no place in this world. - unfortunately that's not reality, (problem is, rabble often buys bikes too! ).

[jbiplane]

Any idea what engine is it and specs ~1940 production, used by German military.
Scavenging through piston
346564
346565
346566

[Niels Abildgaard]

Any idea what engine is it and specs ~1940 production, used by German military.
Scavenging through piston
346564
346565
346566

It looks like a drone engine and the scavenge system was named something like Schlika and had been used in motorbikes before WW2.

[Frits Overmars]

Any idea what engine is it and specs ~1940 production, used by German military.
Scavenging through piston
346564
346565
346566Like Niels wrote, it seems to be a boxer with Schliha (spelling!) scavenging through the piston. And the shielded spark plug caps suggest aviation use.
I wonder about the drone application though. Drones were mainly used for target shooting practice, but back then the German Wehrmacht and Luftwaffe had no shortage of real targets.
346578 346577

[husaberg]

Like Niels wrote, it seems to be a boxer with Schliha (spelling!) scavenging through the piston. And the shielded spark plug caps suggest aviation use.
I wonder about the drone application though. Drones were mainly used for target shooting practice, but back then the German Wehrmacht and Luftwaffe had no shortage of real targets.
346578 346577

It reminds me of a RGP warhead.
or i guess in this case a Panzerfaust

[Niels Abildgaard]

Wiki says 20 horsepower 1200ccm and made for an aircraft called erla6

https://de.wikipedia.org/wiki/Erla_6

Erla6 was a intermidiate trainer between gliders and real aircrafts for Luftwaffe pilots to be.

[jbiplane]

Thanks ALL !!! You are always have answers on any 2-stroke questions :)
Guys who have this engine strongly believe it is 45hp and trying to find investor to reborn.
Me sceptical to this idea :)

[Niels Abildgaard]

Thanks ALL !!! You are always have answers on any 2-stroke questions :)
Guys who have this engine strongly believe it is 45hp and trying to find investor to reborn.
Me sceptical to this idea :)

How did a german prototype aircraft engine from the late thities suvive 80 years in Russia?
There is a very interesting story I think.
I will love to read it.

[WilDun]

How did a german prototype aircraft engine from the late thities suvive 80 years in Russia?
There is a very interesting story I think.
I will love to read it.

I'm told that the Ford (Model A) engines survived in a Soviet "Jeep" till after WW2. (however I can't confirm that - just something I remember reading).
The Russians were often able make good use of things the Americans didn't persevere with! (like the mid engined Bell Airacobra aircraft which they used with great success as a ground attack aircraft).

[katinas]

It is still difficult to imagine, how something could have been created during Stalin's terror. From the 1930s to the 1950s, the vast majority of the Russian and Ukrainian intelligent mind was either killed or imprisoned. Before and after the war, the most needed and “dangerous” minds were locked up in Sharashka ( https://en.wikipedia.org/wiki/Sharashka
https://en.wikipedia.org/wiki/Gorodomlya_Island) Sergei Pavlovich Korolev together with Helmut Gröttrup.
Stalin wanted copy everything, to the smallest detail, even, a random hole in the body of example bomber Boeing B-29 was copied to TU-4.
In Soviet times, say in Lithuania, every factory was working for military and all this was hidden under a wide variety of productions for civilians. Remember, the tape recorder factory in Vilnius, that main production actually was recording equipment (with recording wire) for submarines.

After the war, most of the DKW factory was transferred to the Soviet land and the DKW reborn in two-stroke racing motorcycles as ГК-1, С1Б, С2Б, С3В. They were developed until FIM banned supercharging.

Add pic with similar type to Schliha, just reversed.

[Niels Abildgaard]

It is still difficult to imagine, how something could have been created during Stalin's terror. From the 1930s to the 1950s, the vast majority of the Russian and Ukrainian intelligent mind was either killed or imprisoned. Before and after the war, the most needed and “dangerous” minds were locked up in Sharashka ( https://en.wikipedia.org/wiki/Sharashka
https://en.wikipedia.org/wiki/Gorodomlya_Island) Sergei Pavlovich Korolev together with Helmut Gröttrup.
Stalin wanted copy everything, to the smallest detail, even, a random hole in the body of example bomber Boeing B-29 was copied to TU-4.
In Soviet times, say in Lithuania, every factory was working for military and all this was hidden under a wide variety of productions for civilians. Remember, the tape recorder factory in Vilnius, that main production actually was recording equipment (with recording wire) for submarines.

After the war, most of the DKW factory was transferred to the Soviet land and the DKW reborn in two-stroke racing motorcycles as ГК-1, С1Б, С2Б, С3В. They were developed until FIM banned supercharging.

Add pic with similar type to Schliha, just reversed.

It starts to get very interesting.
The pictures from JBIPLANE were judged to be of Schliha type by me and at least another have seen it all .
We were wrong methinks..
They look more as the russian devellopment according to Katinas second but last picture.
Exhaust is not controlled by main piston but by the piston- extension to top of head and overboard.
The second picture from my colleaque in having seen everything and Katinas last pictures show Schliha where exhaust leaves mid cylinder.
The aeroplane picture with the true Schliha engine is from ca 1937 Germany.
Both the Schliha and the russian devellopment would have been simpler and better with normal valves in top.
I think
Spending time here , enjoy some numbers.

https://www.homebuiltairplanes.com/forums/threads/side-valved-two-strokes-for-angels.32119/

[katinas]

Niels, last picture in previous post, is Erla6 plane with true Schliha engine. As plane was more oriented for peace time, there is no interest in them from Germany militarists before war.

[jbiplane]

How did a german prototype aircraft engine from the late thities suvive 80 years in Russia?
There is a very interesting story I think.
I will love to read it.

The guy who own it says he take it in watersport section in Samara city ~20 years ago. They reworked such engines to water cooling.

[Niels Abildgaard]

The guy who own it says he take it in watersport section in Samara city ~20 years ago. They reworked such engines to water cooling.

A russian pendant to McCullogh drone engines?

https://www.wingsofhistory.org/mcculloch-40-hp/

Would be interesting to compare fuel efficiency numbers.

[jbiplane]

A russian pendant to McCullogh drone engines?

https://www.wingsofhistory.org/mcculloch-40-hp/

Would be interesting to compare fuel efficiency numbers.

In Soviet union for drones produced 38hp 12.6 kg (without reducer) engines
346621

Used on crafts like tuis
346622

Tomorrow leave on holydays. Probavly will out of internet couple of weeks or so.

[Niels Abildgaard]

In Soviet union for drones produced 38hp 12.6 kg (without reducer) engines
346621

Used on crafts like tuis
346622

Tomorrow leave on holydays. Probavly will out of internet couple of weeks or so.

Hollidays are not so important as history of this strange,old reverse Schliha aircraft engine that later was modified for water cooling.
OK enjoy your holliday but do not forget us for wine ,sunshine and women.

[breezy]

346652 would this be considered an opposed piston engine?