the clean two-stroke thread

[breezy]

nice one husaberg...read most of it .... now i have a head ache:facepalm: it seems as though jumping through hoops for the 2 stroke to comply has been established by those who decide the rules.. and then some... the options of F1 cars taking up this 2 stroke opposed engine set up seem almost impossible with 2t exhaust set ups as we know them... turbo charging and putting all the exhaust fumes through a number of filters would seem the only option to comply.

[breezy]

I assume this thread is more about disscusion on concepts, evaluating running prototypes and theory.
I can show the occasional pictures of my uniflow here but the build pictures I'll take back to the Bucket Foundry, yes?

Flettner,

will your opposed engine have a turbo? how will you lubricate big and small ends?

[Flettner]

Flettner,

will your opposed engine have a turbo? how will you lubricate big and small ends?

Sorry Breezy, I haven't got round to doing a picture yet, Ill get onto it.
No turbo, crank case pump for compactness and simple (er).
Bigend oiling is like my 360 Mk2 TPI engine. Direct to the bigend through a hollow crankshaft, air assist, autolube.

[WilDun]

Sorry Breezy, I haven't got round to doing a picture yet, Ill get onto it.
No turbo, crank case pump for compactness and simple (er).
Bigend oiling is like my 360 Mk2 TPI engine. Direct to the bigend through a hollow crankshaft, air assist, autolube.
Will your Autolube system be similar to the system used by Suzuki in the T20, T250/350 etc - ie 50 years ago? (except for the air assist) - and will it be 'total loss', - ie. will it end up in the air/fuel mix?

[Flettner]

Will your Autolube system be similar to the system used by Suzuki in the T20, T250/350 etc - ie 50 years ago? (except for the air assist) - and will it be 'total loss', - ie. will it end up in the air/fuel mix?

Yes, this version.
Next version, no.

[WilDun]

Yes, this version.
Next version, no.

That sounds good! :niceone:

[Flettner]

Might have to go all LPG fueling on its ass, bugger it.
I won't run petrol, E85 seems like its out now. Green NZ, yeah right.
Might be a bit awkward fitting an LPG bottle into an enduro bike. What pressure is LPG, 80 PSI ?
LPG might have excellent cooling properties for the hot end of my OP uniflow engine though.

[WilDun]

Might have to go all LPG fueling on its ass, bugger it.
I won't run petrol, E85 seems like its out now. Green NZ, yeah right.
Might be a bit awquid fitting an LPG bottle into an enduro bike. What pressure is LPG, 80 PSI ?
LPG might have excellent cooling properties for the hot end of my OP uniflow engine though.

Think it was 145psi last time I looked (for LPG). - that's the trouble with bikes - no space!

[Flettner]

LPG, bad idea.
Pressure too vairable, according to outside temp, although the Link could be programmed to change the master fuel depending on fuel pressure / temp but too much hassle.

[husaberg]

LPG, bad idea.
Pressure too vairable, according to outside temp, although the Link could be programmed to change the master fuel depending on fuel pressure / temp but too much hassle.

LPG might provide the HCCI though from memory it will not compression ignite until well after diesel does.
people used to use it much like a mild form of nitros in turbo diesels as it has an intercooler effect as well.

25% power increase.
https://drivetribe.com/p/lpg-injection-to-diesel-engines-I8aDHIwyQpuAOdkkp3vQmQ?iid=HFVyg0QnT2ClxmdwTz3Z5w

You could direct inject a tiny amount of Diesel into the combustion chamber

[Flettner]

LPG might provide the HCCI though from memory it will not compression ignite until well after diesel does.
people used to use it much like a mild form of nitros in turbo diesels as it has an intercooler effect as well.

25% power increase.
https://drivetribe.com/p/lpg-injection-to-diesel-engines-I8aDHIwyQpuAOdkkp3vQmQ?iid=HFVyg0QnT2ClxmdwTz3Z5w

You could direct inject a tiny amount of Diesel into the combustion chamber

Don't worry, thats one of the many plans I have set out for this engine. Although I was wanting to use ethanol as the base fuel.

[husaberg]

Don't worry, thats one of the many plans I have set out for this engine. Although I was wanting to use ethanol as the base fuel.

The LPG injection its called LPG Fumigation as it was basically just misted into the air intake.
https://web.archive.org/web/20120729024731/http://www.mrsharkey.com/lpg.htm

The wankel i think was investigated as it works kind of reasonable with Hydrogen likely because combustion area is seperated from the other areas.
i want to see the sleeve engine.

[Frits Overmars]

Will your Autolube system be similar to the system used by Suzuki in the T20, T250/350 etc - ie 50 years ago? Neil is pressure-feeding oil directly to the big end bearings. I don't think Suzuki ever did that on their road-going two-strokes. The best I can remember was them feeding oil directly to the T500 and T750 crankshaft main bearings.

[ken seeber]

Neil is pressure-feeding oil directly to the big end bearings. I don't think Suzuki ever did that on their road-going two-strokes. The best I can remember was them feeding oil directly to the T500 and T750 crankshaft main bearings.

Frits, seeing you’re so young, you mightn’t remember the Suzuki T6/X6/Hustler of the mid 60s onwards. This had the Posiforce system which fed the mains through catchment plates surrounding the main bearing outer races, then thru to the hollow crankpins to the big end. The T500 & GT750 had this, and I think, more feeds into each intake.

[Frits Overmars]

Frits, seeing you’re so young, you mightn’t remember the Suzuki T6/X6/Hustler of the mid 60s onwards. This had the Posiforce system which fed the mains through catchment plates surrounding the main bearing outer races, then thru to the hollow crankpins to the big end. The T500 & GT750 had this, and I think, more feeds into each intake.I remember those, Ken. But the centrifugal effect in these catchment plates can only build up a small amount of pressure, depending upon the diameter of the cachtment plate trenches and on crankshaft rpm. There is no relation between the oil pump pressure and the tiny pressure with which the oil enters the hollow crankpins. I do not consider this pressure-feeding the big end bearings.

[ken seeber]

I remember those, Ken. But the centrifugal effect in these catchment plates can only build up a small amount of pressure, depending upon the difference between the inner and outer diameters of the cachtment plate trenches and on crankshaft rpm. There is no relation between the oil pump pressure and the tiny pressure with which the oil enters the hollow crankpins. I do not consider this pressure-feeding the big end bearings.

Yeah, fair enough Frits. I guess it comes down to some form of definition as to what pressure fed means. I would think that it means, a high oil pressure feed to suit plain bearings, eg like every auto 4 stroke. Given this, a pressure fed big end would be unsuitable for a crankcase scavenged 2 stroke due to the relatively high flow rate of oil thru the bearing, so agree with you re road going 2 strokes.
It would be interesting to know if, ultimately, did this directed flow to the big ends, offer an improved life to the bearing.

[WilDun]

Neil is pressure-feeding oil directly to the big end bearings. I don't think Suzuki ever did that on their road-going two-strokes. The best I can remember was them feeding oil directly to the T500 and T750 crankshaft main bearings.

I remember very well indeed (just more or less as you described it Ken ...... except I didn't see your post - but I'll confirm that!) - the T20 (Hustler) had the oil pumped to the mains (low pressure, of course - more of an adjustable trickle than high pressure fed of course, being through ball bearings). There was a sheetmetal collector at the inside of the bearing (like a big washer with curled over outer edge and had a rolled tube extension going up into the hollow crankpin, the (oil being fed in by centrifugal force - and quite considerable force too I would think!). The big end was then fed through a hole from the crankpin (like any common or garden four stroke) - it was much more sophisticated than the Yamaha Autolube system! and quite an innovation - I thought so anyway!

[Frits Overmars]

It would be interesting to know if, ultimately, did this directed flow to the big ends, offer an improved life to the bearing.In the case of the Suzuki catchment plates I have no solid knowledge, but in any case, if I had one of those Suzukis, I would keep the system operational.
In the case of real pressurized feed of the kind that Flettner is using, the knowledge is there: Helmut Fath built it on the Yamaha racers of Phil Read and claimed 'about a tenfold increased lifespan'.


IThere was a sheetmetal collector at the inside of the bearing (like a big washer with curled over outer edge and had a rolled tube extension going up into the hollow crankpin, the (oil being fed in by centrifugal force - and quite considerable force too I would think!). The big end was then fed through a hole from the crankpin (like any common or garden four stroke) - it was much more sophisticated than the Yamaha Autolube system! and quite an innovation - I thought so anyway!It was a more sophisticated system than the Yamaha Autolube system, allright. But not quite an innovation; BMW used these metal oil collectors on all their twins long before Suzuki did. I am sure I wrote about the BMW system not too long ago - just can't remember where it was.

Before we dismiss the Yamaha Autolube system, let's realise that it was developed for affordable street bikes. Yahama had already demonstrated in the 1960's that they knew how to provide proper pressurised lubrication for their race bikes.
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[lohring]

I'm sure someone has posted this somewhere, but this is the latest attempt at a clean diesel two stroke. At 1000 hp it's a little big for your car, though.

https://www.caranddriver.com/features/columns/a25224238/achates-opposed-piston-engine/

Lohring Miller

[WilDun]

In the case of the Suzuki catchment plates I have no solid knowledge, but in any case, if I had one of those Suzukis, I would keep the system operational.
In the case of real pressurized feed of the kind that Flettner is using, the knowledge is there: Helmut Fath built it on the Yamaha racers of Phil Read and claimed 'about a tenfold increased lifespan'.................................

Reminds me of the "Tecalemit" multi point machine tool lube system! (On the Yamaha GP bike).
I would never dismiss any of these ideas (especially the Suzuki T20 etc.) which we should have really paid more attention to! - it was very simple and effective.
Recently, someone mentioned this "new, revolutionary oiling system" somewhere on ESE - it was being well recieved and I couldn't believe that no one seemed to know about it previously! ...... it was then I noticed just how old I was becoming!

In my days of "T20-ing" those doing serious racing with them actually abandoned it and went back to petroil mixture - not sure why but it seemed to be because of adjustment of the low pressure pump which I guess if set incorrectly could be the cause of piston seizures (the adjustment of the pump did both cylinders together (no individual adjustment) - but I'm sure that someone here knows a lot more than I do!).

In it's heyday, the T20 was raced by a lot of guys (stock and all looked the same) and I remember seeing about eight of them all parked up in the paddock waiting for the call for the next race.
To fill in the time I decided to check my gearbox oil level and I was busily removing the oil plug when I heard this voice behind me "ahem, - excuse me - are you trying to sabotage my bike?" ....... :facepalm: :o




I'm sure someone has posted this somewhere, but this is the latest attempt at a clean diesel two stroke. At 1000 hp it's a little big for your car, though.

https://www.caranddriver.com/features/columns/a25224238/achates-opposed-piston-engine/

Lohring Miller

Yeah that engine was inspired by the Junkers Jumo (so says the guy in charge) - and he probably knows more and has more experimental data collected on that layout than than just about anyone else on the planet! - the fact that the big companies are seriously interested (and involved in its development) says a lot!
Now we've got to miniaturize it a little!

[Flettner]

No good, it's a diesel. Diesel is dead, too much particulates to deal with.
My new truck has lost approx 150 kl off its range over the old one. Particular filter is the fault.

[WilDun]

No good, it's a diesel. Diesel is dead, too much particulates to deal with.
My new truck has lost approx 150 kl off its range over the old one. Particular filter is the fault.

Yep, but I'm referring more to the engine layout than the type of fuel - think there must be a way round the cooling of that piston if using petrol!

New isn't always better! - I always used to wonder when in the past they didn't seem to worry about diesel emissions - in Auckland the cretins turned down Robbie's Rapid Rail idea and replaced the electric trolley buses with diesel buses - morons!

As for that (OP) system using petrol with HCCI (which apparently runs well staying at higher revs, but has to keep changing back to the "normal" system when revs get lower (depending on demand) - the idea of a "semi Hybrid - ie hybrid style transmission with the bare minimum of battery capacity - most of the time the engine will be operating at its most efficient revs (relieved of the chore of having to accelerate and decelerate constantly) no need to go up and down the rev range, surely that must have some merit?
But no doubt I will have overlooked something, somewhere! :rolleyes:

[Flettner]

Why compromise?
Why not HCCI at all revs?
It can be done, rendering spark plugs and ignitions to the rubbish bin.
Seemingly silly experiments can lead to intetesting results 😆.

https://youtu.be/TOHKls3Cxjs

[husaberg]

i will have to dig out the one with the project leader.
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[Flettner]

Honda still needed a sparkplug.

[husaberg]

Honda still needed a sparkplug.

Yes the did and according to them it gave less emissions than a equivalent 4 stroke at the time.
the ARC was to autoignite at low to mid revs.
ie 5%-60% load ie the time when it would be prone to 4 stroking.



Opening up the throttle on the Baja-winning EXP-2, I aimed the bike down a desert trail at the dust storm following test rider and former Baja winner Bruce Ogilvie. As the EXP-2 blasted off down the trail, its engine note changed from a two-stroke burble to the clattering of pre-ignition.
Ignoring the warning of impending doom I opened the throttle wider and hung on.
Every other two stroke in the world would have seized solid, right then. But the EXP-2 pulled away without protest.
What's different about the EXP-2 is the weird, muted note to the exhaust -- like a watercraft -- and the clattering noise of pre-ignition (commonly referred to as knocking or pinging) at low- to medium-throttle openings and engine RPM.
Honda has tamed pre-ignition; on the EXP-2 this auto-ignition is computer controlled to enhance performance and most importantly virtually eliminate pollution.
Usually thought of as a bastion of four-stroke technology, Honda's new two-stroke design promises less pollution, better fuel economy and most important, no loss in power.

Pre-ignition will destroy a normal two stroke. It is caused when the temperature and pressure in a cylinder builds to a critical point and the air/fuel mixture ignites prematurely in a violent explosion rather than in a controlled burn.
The premature explosions are ignited either by red-hot engine parts or highly ionized reactive molecules left from the last exhaust cycle.
Using premature combustion to more thoroughly burn the mixture is not a new idea -- diesels don't have spark plugs either.
But it's the first time that auto-ignition has been successfully applied to a gasoline two-stroke.

Above idle, and below 40 percent throttle, the spark plug is not used. The exhaust power valve automatically regulates combustion pressure, guaranteeing that pre-ignition will start and end at the correct time.
Once the critical pressure is reached, the reactive molecules act like millions of tiny spark plugs, firing the mixture much more evenly than any single plug could.
Honda claims that when the ARC is engaged, carbon monoxide and carbon dioxide emissions are 15 percent lower, hydrocarbons are down 80 percent, and Nitrous Oxide emissions are down 90 percent...'
Before the emergence of microprocessors, engine management systems were not precise enough to control combustion pressure at all engine speeds.
However, with a computer controlled exhaust valve (shown below), pressure in the combustion chamber can be precisely controlled, so pre-ignition can be timed as precisely as an ignition spark.
The engine control unit relies on throttle position and engine speed sensors, and uses a knock sensor to detect low-octane fuel.

The EXP-2 uses two electronic fuel injectors (shown at right) but engineers at Honda say carburetors would work just as well. Honda claims that when the ARC (Activated Radical Combustion) is engaged (from idle to about half-throttle) carbon monoxide and carbon dioxide emissions are 15 percent lower, hydrocarbons are down 80 percent and Nitrous Oxide emissions are down 90 percent compared to conventional engines. At idle and at high throttle openings, ignition is by spark plug and emissions are similar to other two strokes. Why did Honda bother? In case you haven't heard, there are restrictive exhaust emissions laws coming down on motorcycles in many countries. Due to their greater emissions two-stroke have been especially hard-hit. Two-strokes are no longer legal for road use in the US and some countries in Europe may ban them.

In California two-strokes will soon be illegal for off-road use except on 'closed courses'. A sad story-until Honda came along offering new hope with a radical new design.
Not content to merely run the new EXP-2 (for experimental two-stroke) engines on the dyno, Honda built a couple of trick off-road rally bikes and entered them in three grueling rallies to race against the best riders in the world, most riding bigger, faster machines. After fourteen days of African desert racing in the Paris-Granada rally (previously the Paris Dakar)
J. Brucy's EXP-2 finished 5th overall and first in the under-500cc class. In the punishing week-long Nevada rally, Bruce Ogilvie finished 8th overall, and in the Baja 1000 Honda's riding team of Chuck Miller, Paul Ostbo and Greg Bringle finished 7th overall and first in class. "
We packed up our riding gear and met Honda at a secret location in the Mojave desert to test the EXP-2." After the EXP-2 proved it could stand up to this kind of destructive treatment, Honda let Motorcycle Online ride it.
. Some differences are obvious, like the the main frame, hand-built from aluminum tube and sheet. Other parts are more familiar.
The rear sub-frame is sourced from a CR500, as are the seat and fender. The swing-arm is the same size as a CR500 item and is suspended by a Showa shock.
The forks are conventional (right-side up) Showa items. A small fairing bolts to a bracket attached to the frame headstock, and can be replaced with a set of headlights for night riding.
Flip the ignition switch hidden in the radiator shroud and the powervalve motor whines as it cycles the valve to the starting position and the fuel pump charges the fuel injection system.
The bike kicks over easily for a 400cc single and fires right up. The motor has a mildly-tuned low-end, and top-end similar to an open-class MX bike. In between there's no sudden hit to the powerband, just more power when the rider twists the throttle. The desert gearing is tall, but the friendly powerband makes the bike controllable and fun to ride. That makes life easier for rally riders doing 8 or 10-hour stints in the saddle. We followed Bruce Ogilvie around the desert for a while. Bruce, a former Baja 1000 winner and really fast guy was polite enough to wait at each intersection for us to catch up. 'For an experimental bike, it's very well behaved.

The EXP engine has an effective counterbalancer, so the rider doesn't feel any more vibration than a 125 would produce.' The EXP's suspension has a fairly stiff initial travel, necessary for a desert bike to keep the bike riding high on its suspension so there's room to absorb hard hits. At the speed we were riding we couldn't bottom the suspension. The bike is pretty stable but turns well for a 280-pound desert bike.
The broad powerband helps by making it easy to get the rear end to slide just the right amount to carve the turn. For an experimental bike, it's very well behaved. The EXP engine has an effective counterbalancer, so the rider doesn't feel any more vibration than a 125 would produce. This is important for rally riding- reducing the rider's fatigue lets him ride faster for longer. The 6-gallon fuel tank is narrow at the back compared to the Paris-Granada version's huge tank so the rider can move forward to weight the front end. We tried to get the bike to detonate unintentionally by lugging it in a sand wash, but it didn't misbehave in any way. Other than the odd engine noise it's easy to forget that the bike is fuel injected and makes less pollution than a weed-wacker. After a morning of riding there wasn't any more residue in the tailpipe than a four-stroke would produce.

Even the inside of the silencer stayed clean, an impressive vindication of the low emission design. Honda plan to campaign the EXP-2 again next year.
The company says it has no plans to make a production engine right away, but from the success so far, we'd predict that the world's cleanest two stroke motorcycle will be in production before the year 2000. In addition to direct fuel injection, there are other technologies that can help. Two decades ago, Honda introduced a 250cc, two-stroke motorcycle engine for a Japanese-market-only dual-purpose bike that utilized “Activated Radical Combustion.”
This is a technology that has since been well-studied by the automotive industry and is more commonly known as HCCI (Homogenous Charge Compression Ignition), a combustion process that requires no spark but uses gasoline rather than diesel fuel. In Honda’s 250, HCCI combustion was maintained from about eight to 50 percent load, with conventional spark ignition used at both the high and low end of the engine load range.

The benefit was far more stable combustion (no six- or eight-cycling) when HCCI was operating, lower emissions and—according to those who rode it—a two-stroke that felt as if it had the smooth power of a four-stroke.
Honda’s patents have since expired. For those who dont know, the CRM250AR was the production version of the EXP-2 Enduro prototype that used Active Radical Combustions to decrease emissions. The bike at low revs and low throttle openings closes and exhaust flap (hondas fancy word por PV) and introduces hot exhaust gases back into the cylinder to become thousands of tiny spark plugs (known as Active Radicals). Therefore, the Spark ignition is no longer required, the engine 'diesels' as it undergoes controlled detonation combustion. When Undergoing AR combustion the engine purrs steadily without the expecting 'ring-ding-ding' unsteady combustion cycles common in two strokes. its almost akin to a four stroke. Crank the throttle open and the engine comes to live with potency close to a CR250 Honda.

[Flettner]

Yes, but, wouldn't you want better control than that?
Honda clearly didn't pursue this, why?

[husaberg]

Yes, but, wouldn't you want better control than that?
Honda clearly didn't pursue this, why?

i posted the text out of the attachment. have a read through
there is a better write up over about 6 pages in a US mag of the time that has a lot of details from the peple that did it when i dig it out i will post it.
they basically said it didnt need fuel injection either it was just easier to set up.
the dude said they could control it with the exhaust vale more accurately than the Plug, but they only needed to do this under 60%
plus as the exhaust valve controlled the port it needed to be open up top revs........


They did pursue the tecnology and they did patent it, they made a road bike version the CRM250ARC, just like with the 8 valve NR750.
but they are in the business to sell what people want and that was the CRF's plus it suited the corporate image to only sell 4 strokes.

[WilDun]

All very interesting! - but I was going to say why did Honda let the patent lapse? but that was answered by someone - Husa? - it didn't suit their sales strategy at the time, also it was at a time when they were trying to promote change to the four stroke instead!

Still seems strange that they let it lapse - It would indicate that they were not worried about it being used by others as the four stroke had gained enough ground to keep it ahead and no one was willing to take a chance on it and lose their reputation, when they were already doing OK!!

Last century was when breakthroughs were in full swing, this century - refinements and electronic enhancement instead!

But as Frits would say - K.I.S.S!

[Frits Overmars]

Last century was when breakthroughs were in full swing, this century - refinements and electronic enhancement instead!
But as Frits would say - K.I.S.S!That's a safe bet Will; I will always say KISS. But that was not my first reaction when reading your post. It was this:
347026
I wonder how that man got his job. Must have been something political.
Not only is the 21st century bringing us more breakthroughs - they are coming at an ever-increasing pace.
Makes me wonder what the world is coming to. It also makes me wish to keep on living for another full century, so I can see for myself :D.

[Norman]

All very interesting! - but I was going to say why did Honda let the patent lapse? but that was answered by someone - Husa? - it didn't suit their sales strategy at the time, also it was at a time when they were trying to promote change to the four stroke instead!

Still seems strange that they let it lapse - It would indicate that they were not worried about it being used by others as the four stroke had gained enough ground to keep it ahead and no one was willing to take a chance on it and lose their reputation, when they were already doing OK!!

Last century was when breakthroughs were in full swing, this century - refinements and electronic enhancement instead!

But as Frits would say - K.I.S.S!


When you have some time over this long article, even though it goes ten years back, is quite interesting and it also gives some insight info and thoughts about Honda and two strokes and the CRM250.
https://www.dirtbikeplanet.com/future-of-two-strokes/

[WilDun]

Frits,
I need to stress that I am not a 'bible banger' but ..... we need to check out all ancient wisdom wherever it come from!
Here is a quote (this time from the bible and unfortunately for you, in 16th century English!) - this one has always intrigued me! :-

9 The thing that hath been, it is that which shall be; and that which is done is that which shall be done: and there is no new thing under the sun.

10 Is there any thing whereof it may be said, See, this is new? it hath been already of old time, which was before us.

11 There is no remembrance of former things; neither shall there be any remembrance of things that are to come with those that shall come after.

So, a 'breakthrough' it would seem is Dis - Covering , as opposed to inventing!

Definitely words of wisdom from someone way way in the past - way before the sixteenth century, - even way before the days of the bible! - but it also applies to us on our little 'put put' machines as well! ...... the Suzuki lubrication system comes to mind here of course, - but there is a huge pool of great ideas buried under glitzy dumbass (but popular) ideas! - So these can be rummaged through, picked out one by one, modified, reassembled in various ways and called 'inventions' :innocent:


When you have some time over this long article, even though it goes ten years back, is quite interesting and it also gives some insight info and thoughts about Honda and two strokes and the CRM250.
https://www.dirtbikeplanet.com/future-of-two-strokes/

Thanks Norman, will do that - I had hoped for renewed interest in the two stroke and hopefully we are all beginning to wake up and go back over what has already been tried but just shelved till there is an opportunity to use it!
I don't necessarily know or understand much really, but I do know that some things have to be brought up and reviewed - and all possibilities discussed - as Flettner said, seemingly silly experiments can bring up surprising results!

[ceci]

When you have some time over this long article, even though it goes ten years back, is quite interesting and it also gives some insight info and thoughts about Honda and two strokes and the CRM250.
https://www.dirtbikeplanet.com/future-of-two-strokes/


Sorry but I'm going to spoil it.
This long article is the work of a Master of 2S who believed that there can be a 2S solution without the need for electronics
After analyzing all the existing solutions, which solution the author article himself: dispense with electronics

[WilDun]

Sorry but I'm going to spoil it.
This long article is the work of a Master of 2S who believed that there can be a 2S solution without the need for electronics
After analyzing all the existing solutions, which solution the author article himself: dispense with electronics

I'm sure that is possible - but here is an analogy :-
If you have a wife, go and tell her that she doesn't need a cellphone, a vacuum cleaner, a washing machine or drier and she can't have a car to go and indulge in a shopping spree! - Sure, it will work and she will still be able to survive without these things, but if she is pretty and talented, then she may want to do some more shopping elswhere! :msn-wink:

Moral of the story don't cut off the frills entirely - although sensible, you'll lose your 'not so clever' buying public!

[Flettner]

Electronics are not the enemy, although mechanicly we can do better than the loop scavenge twostroke, in my opinion.
Combined, we may have something worthwhile.

[WilDun]

Electronics are not the enemy, although mechanicly we can do better than the loop scavenge twostroke, in my opinion.
Combined, we may have something worthwhile.

Yep - it will need a lot of experiment which I really couldn't do in my present situation (perhaps never could!) - there may be a few failures on the way but each failure will be another lesson! - and if there's good electronic equipment and other parts lying around that we could scrounge, we'd be fools not to use it in those experiments! - nobody who invented (or discovered) anything, ever did things entirely ''textbook style" ! :niceone:

[ceci]

I'm sure that is possible - but here is an analogy :-
If you have a wife, go and tell her that she doesn't need a cellphone, a vacuum cleaner, a washing machine or drier and she can't have a car to go and indulge in a shopping spree! - Sure, it will work and she will still be able to survive without these things, but if she is pretty and talented, then she may want to do some more shopping elswhere! :msn-wink:

Moral of the story don't cut off the frills entirely - although sensible, you'll lose your 'not so clever' buying public!



You have a PRETTY wife, but she doesn't know how to love, iron, cook, sew, keep the house clean.
What do you do, do you stay with her or change her for the ugly one
The useful is what really counts, the beautiful attracts more but is useless.
Tim trans analyzed all the systems he decided to create his and this one without electronics, why ?: Very simple, cheaper and that works for the whole planet

https://www.facebook.com/media/set/?set=oa.110145955824143&type=3

[Flettner]

You have a PRETTY wife, but she doesn't know how to love, iron, cook, sew, keep the house clean.
What do you do, do you stay with her or change her for the ugly one
The useful is what really counts, the beautiful attracts more but is useless.
Tim trans analyzed all the systems he decided to create his and this one without electronics, why ?: Very simple, cheaper and that works for the whole planet

https://www.facebook.com/media/set/?set=oa.110145955824143&type=3

But does it work? Has he built one? Some results?

[ceci]

But does it work? Has he built one? Some results?



I have no answers to these questions.
What is undeniable is Tim's will to solve the 2S contamination problem.

http://www.pit-lane.biz/t5235-2-stroke-fast-by-tim-hickox

[husaberg]

All very interesting! - but I was going to say why did Honda let the patent lapse? but that was answered by someone - Husa? - it didn't suit their sales strategy at the time, also it was at a time when they were trying to promote change to the four stroke instead!

Still seems strange that they let it lapse - It would indicate that they were not worried about it being used by others as the four stroke had gained enough ground to keep it ahead and no one was willing to take a chance on it and lose their reputation, when they were already doing OK!!

Last century was when breakthroughs were in full swing, this century - refinements and electronic enhancement instead!

But as Frits would say - K.I.S.S!

Patents last 20 years only then its generic technology

[Frits Overmars]

https://www.facebook.com/media/set/?set=oa.110145955824143&type=3This Facebook presentation was not exactly confidence inspiring:
347030

[WilDun]

You have a PRETTY wife, but she doesn't know how to love, iron, cook, sew, keep the house clean.
What do you do, do you stay with her or change her for the ugly one ................................


No, I would just find her a job and send her off to work instead ....... and I would stay at home, tidying up the house etc. (takes the best part of an hour) then spend the rest of my day designing and building the perfect two stroke! - might even employ a housekeeper! .......... then maybe not - my age might not allow me to do that! - oh well! :msn-wink:

[WilDun]

You have a PRETTY wife, but she doesn't know how to love, iron, cook, sew, keep the house clean.
What do you do, do you stay with her or change her for the ugly one ................................


Ceci
No, I would just find her a job and send her off to work instead ....... and I would stay at home, tidying up the house etc. (takes the best part of an hour) then spend the rest of my day designing and building the perfect two stroke! - might even employ a housekeeper! .......... then maybe not - my age might not allow me to do that! - oh well! :msn-wink:

Norman
Thanks for that article - that was written just when I was starting to take an interest in motorcycles again after over 25 years off, so I hadn't read much about developments around then.
I found it very interesting indeed and agreed entirely with most of what he was saying , but I had always looked on a two stroke as a competition machine with Schneurle scavenging (as this guy obviously did.) ...... I think Uniflow now!

Since my life had changed dramatically through severe health problems, I could no longer ride bikes (to do so and risk falling off would have been the end for me!) - then I found computers and forums! and have never stopped talking since! :laugh:

I am still learning and just as keen as I was over 50 years ago, but my ideas have changed and I am more concerned with the fate of the more mundane two stroke and how to make it as clean as these exotic competition machines, but still keep it inexpensive! ..... ie in the future when it might actually need to be the breadwinner (through huge sales in the commuter market etc).

Maybe Ceci is right about ditching electronics I dunno - but why? when it works fine and is actually well developed and relatively cheap!

Anyway thanks for sharing :niceone:

[Frits Overmars]

Maybe Ceci is right about ditching electronics I dunno - but why? when it works fine and is actually well developed and relatively cheap!Can we achieve our goal without electronics? If No: use electronics.
Do we need to resort to complicated workarounds in order to achieve our goal without electronics? If Yes: use electronics.
Can you agree with this, Ceci?

[ceci]

This Facebook presentation was not exactly confidence inspiring:
347030

You know that the same method is used in Pierre Duret's IAPAC system, the use of a plenum.
I forgot that IAPAC uses electronic injectors and that will surely work.
https://images-na.ssl-images-amazon.com/images/I/41cvLOI5Z7L.jpghttps://encrypted-tbn0.gstatic.com/images?q=tbn%3AANd9GcQCqHUzUMwOmOFQxrj-kIA_AzAzcevzjdrcgw&usqp=CAU





Can we achieve our goal without electronics? If No: use electronics.
Do we need to resort to complicated workarounds in order to achieve our goal without electronics? If Yes: use electronics.
Can you agree with this, Ceci?


Perhaps I am the only one in this thread that defends that idea, but over time if we look at the literature we will see great researchers who defended this idea

[WilDun]

You know that the same method is used in Pierre Duret's IAPAC system, the use of a plenum.
I forgot that IAPAC uses electronic injectors and that will surely work.............................................. .
Perhaps I am the only one in this thread that defends that idea, but over time if we look at the literature we will see great researchers who defended this idea

That link you gave us will take (me at least) a while to digest properly and I've only just gone through it once quickly, (probably will need a little while and a couple of "read throughs" ..... same thing for the link Norman posted and then I need to understand the RYGER as well.

I didn't really pay much attention to the RYGER when it was such a controversy on the ESE Thread a few years ago! so finding some more info on that and how it (nearly) worked is on my list! (I'm sure katinas will help there!)

I knew that there was a concerted effort to keep the 4 stroke alive and the 2 stroke at bay (by "skullduggery and misinformation") but didn't actually realize the extent of it all!

However, all this is still only trying to address the "failings" of the Schnuerle type system and patch all those up - I do feel that a complete new design is necessary for the two stroke in general - the OP engine (and uniflow in general) being (to me anyway) a good candidate, despite having maybe a couple of (percieved) disadvantages!

I think there is room for electronics to be used to be an improvement over stark simplicity! especially if it's only being kept simple for the sake of being able to say "this engine is electronics free" we will end up with a smooth operating efficient machine, without a lot of extra cost!

Anyway it's good to see all that pent up passion is still there and beginning to resurface!

[Vannik]

You know that the same method is used in Pierre Duret's IAPAC system, the use of a plenum.
Perhaps I am the only one in this thread that defends that idea, but over time if we look at the literature we will see great researchers who defended this idea

Ceci, I bought that book when it was published, keep in mind it summarizes the research of the late 80's, more than 30 years ago!

Modern electronics, of the last 5 years or so has become a lot cheaper.

[Flettner]

Percived dissadvanges of the OP.
Height or width if you lay it sideways in a bike frame.
Joining the crankshafts.

It can be said two smaller crankshafts is no worse than a single bigger crank with a balance shaft. The two cranks also have the advantage of being simple in design as compared to if the engine was a parallel or vee twin.

Joining..... yes an issue. But if the engine is layed down across the frame with crankshafts pointng forward and aft, a gear set joining them ( four gears ) one being the clutch gear, two connected to the crankshafts and one extra as an idler (I'm sure I could find it a job also), gearbox behind that, CV joint, shaft down to a bevel gear at the rear wheel. Sort of a BMW ish. I've measured against my YZ 250, OP slighly narrower.
This gives lots of room above the engine for fuel and exhaust plumbing. Make an excellent 'adventure' bike.

Edit, I am in no way condoning BMW.

[Frits Overmars]

Percived dissadvanges of the OP.
Height or width if you lay it sideways in a bike frame.
Joining the crankshafts.
It can be said two smaller crankshafts is no worse than a single bigger crank with a balance shaft.
Joining..... yes an issue. But if the engine is layed down across the frame with crankshafts pointng forward and aft, a gear set joining them ( four gears ) one being the clutch gear, two connected to the crankshafts and one extra as an idler (I'm sure I could find it a job also), gearbox behind that, CV joint, shaft down to a bevel gear at the rear wheel. Sort of a BMW ish. I've measured against my YZ 250, OP slighly narrower..How about this Neil?
Only one crankshaft, so no need for a gear train to join two of 'm.
It's a boxer, so no need for a balance shaft.
It will be easy to separate the crankcase from the volumes 'under' the pistons.
You can have your shaft drive without the need for a bevel drive at the gearbox.
It will be a lot narrower than a BMW. In fact you could drop it right into a BMW frame for testing. And with the cultivated behavior of a TPI two-stroke it would make a great touring bike.
347039347040

[Flettner]

Frits, sshhh, 😎 you are spoiling the surprise.

[husaberg]

How about this Neil?
Only one crankshaft, so no need for a gear train to join two of 'm.
It's a boxer, so no need for a balance shaft.
It will be easy to separate the crankcase from the volumes 'under' the pistons.
You can have your shaft drive without the need for a bevel drive at the gearbox.
It will be a lot narrower than a BMW. In fact you could drop it right into a BMW frame for testing. And with the cultivated behavior of a TPI two-stroke it would make a great touring bike.
347039347040
TS3 Horizontally Opposed Piston Engine
Rootes Motor Group built an engine for their trucks which was a design loosely based around an original Sulzer Brothers concept,

http://www.oldengine.org/members/diesel/Rootes-ListerTS3/TS35.jpghttps://www.pattakon.com/patop/CommerTS.gif

but why stop there.

https://www.speednik.com/files/2020/03/video-opposing-views-looking-at-six-opposed-piston-engine-designs-2020-03-20_15-43-26_650673.gif

[Flettner]

I've seen them.
In fact my last 100cc supercharger was a TS3 supercharger cut down to the right width for the required volume.

[Pursang]

https://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=347040&d=1453029352&thumb=1

Nice Idea, Perhaps it was appropriated by Rootes as Spoils of War.
ala DKW-BSA Bantam

[WilDun]

No, Sulzer is a Swiss company, not German - and I believe they are still in business......... Switzerland didn't take part in the war - well, they held the coats while the others fought.

I also remember the TS3 Commer trucks at the local quarry - the drivers used to remove the engine governor - they went like hell!
They were also very smooth running engines (had a trip in one) - very successful engines, but noisy! (although not really noisy inside the cab).
- Still used in some fishing boats till this day!!

The Napier "Deltic" - (second picture) was also very successful as a locomotive engine with British Rail for many years. (think it was 12 cylinder) - it was inspired by the Junkers Jumo (boat engine) which was built under licence by Napier before WW2.

[Pursang]

Hi Bill,
The sectioned engine in Frits' picture is an Auto Union - DKW from 1938.

That's about 10 years & one World War before the Commer.

If the Blueprints for the DKW RT125 made their way back to GB, I bet lots of other stuff did too.

A well know US Automobile manufacturer also had a patent on a Lightweight OP 2stroke diesel back in 1934.
(Shortly after buying a firm with a licensing agreement with the Sulzers).

Totalitarian regimes, with an eye on world domination, are rarely concerned about Intellectual Property laws.

I really like the big tie rod through the rocker pivots holding it all together.
Only needs very light, non-structural outer covers or castings.

https://simanaitissays.files.wordpress.com/2019/06/oldsknocker_01_900-700x615.jpg

Cheers, Daryl

[WilDun]

Hi Bill,
The sectioned engine in Frits' picture is an Auto Union - DKW from 1938.

That's about 10 years & one World War before the Commer.

If the Blueprints for the DKW RT125 made their way back to GB, I bet lots of other stuff did too.

A well know US Automobile manufacturer also had a patent on a Lightweight OP 2stroke diesel back in 1934.
(Shortly after buying a firm with a licensing agreement with the Sulzers).


I was looking to post that one but couldn't find it - From memory, I believe that picture was from the guy (Olds) who started Oldsmobile! - good picture (notice the out of phase cranks?).

[Flettner]

How about this Neil?
Only one crankshaft, so no need for a gear train to join two of 'm.
It's a boxer, so no need for a balance shaft.
It will be easy to separate the crankcase from the volumes 'under' the pistons.
You can have your shaft drive without the need for a bevel drive at the gearbox.
It will be a lot narrower than a BMW. In fact you could drop it right into a BMW frame for testing. And with the cultivated behavior of a TPI two-stroke it would make a great touring bike.
347039347040

I'm combining these https://youtu.be/BPr694nlUKE

https://youtu.be/TOHKls3Cxjs

https://youtu.be/cuSnfRgyEZk

[WilDun]

In the present project, or later?

[Flettner]

No not this one, next perhaps.
This one already had some new stuff to test, one step at a time

[Norman]

Ceci
No, I would just find her a job and send her off to work instead ....... and I would stay at home, tidying up the house etc. (takes the best part of an hour) then spend the rest of my day designing and building the perfect two stroke! - might even employ a housekeeper! .......... then maybe not - my age might not allow me to do that! - oh well! :msn-wink:

Norman
Thanks for that article - that was written just when I was starting to take an interest in motorcycles again after over 25 years off, so I hadn't read much about developments around then.
I found it very interesting indeed and agreed entirely with most of what he was saying , but I had always looked on a two stroke as a competition machine with Schneurle scavenging (as this guy obviously did.) ...... I think Uniflow now!

Since my life had changed dramatically through severe health problems, I could no longer ride bikes (to do so and risk falling off would have been the end for me!) - then I found computers and forums! and have never stopped talking since! :laugh:

I am still learning and just as keen as I was over 50 years ago, but my ideas have changed and I am more concerned with the fate of the more mundane two stroke and how to make it as clean as these exotic competition machines, but still keep it inexpensive! ..... ie in the future when it might actually need to be the breadwinner (through huge sales in the commuter market etc).

Maybe Ceci is right about ditching electronics I dunno - but why? when it works fine and is actually well developed and relatively cheap!

Anyway thanks for sharing :niceone:

Inspiring to hear that you highly enjoy the two stroke world in spite of your health issues Wildun.
One of my school friends father was a two stroke engine designer at Volvo Penta, a very clever man. In their home workshop, with a lot of proto two stroke engines laying around, I more than once got help to fix my expansion chamber needing welding reapair.. But more important, I also got tips to improve the performance of my Suzuki GP125 to be able to keep up with my friends RD125LC:s. Very fun times, the days everything worked as it should that is..! Somewhere there it all went "wrong" and the addiction is there, and I have accepted that it will never go away :laugh:.

[Flettner]

The twostroke virus, yes,

[husaberg]

The twostroke virus, yes,

I have always been intrigued why you were so keen on the Uniflow Neil that one simple animation of the Commer answered it.

[husaberg]

Hi Bill,
The sectioned engine in Frits' picture is an Auto Union - DKW from 1938.

That's about 10 years & one World War before the Commer.

If the Blueprints for the DKW RT125 made their way back to GB, I bet lots of other stuff did too.

A well know US Automobile manufacturer also had a patent on a Lightweight OP 2stroke diesel back in 1934.
(Shortly after buying a firm with a licensing agreement with the Sulzers).

Totalitarian regimes, with an eye on world domination, are rarely concerned about Intellectual Property laws.

I really like the big tie rod through the rocker pivots holding it all together.
Only needs very light, non-structural outer covers or castings.

https://simanaitissays.files.wordpress.com/2019/06/oldsknocker_01_900-700x615.jpg

Cheers, Daryl

Hi Dazza the Simpson as posted by you was 1914
https://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=347039&d=1598602792

[WilDun]

We need to note that the big picture above is not a DKW - possibly Sulzer inspired of course.

There is (to my mind anyway) something wrong in the picture ..... Assuming that crankshaft rotation is clockwise of course, the cranks are clearly not at 180 deg to each other, so the crank controlling the right hand piston has not yet reached the TDC position - so why are both rockers positioned exactly the same - ie at the end of their travel??

This is of course is an OP engine, but it's also a Diesel and Diesels don't figure in the 'clean two stroke' picture these days!

(But I may have got it all wrong!)


Inspiring to hear that you highly enjoy the two stroke world in spite of your health issues Wildun.
One of my school friends father was a two stroke engine designer at Volvo Penta, a very clever man. In their home workshop, with a lot of proto two stroke engines laying around, I more than once got help to fix my expansion chamber needing welding reapair.. .................. Somewhere there it all went "wrong" and the addiction is there, and I have accepted that it will never go away :laugh:.

NORMAN
My health 'problems' aren't really a problem these days (actually have not been for around 10 years - except for one 'flare up') - and it was during the time I was recovering that I found this forum and enjoyed following Flettner's enthusiasm for building his own engines (including his own castings).
I managed to build a small foundry for myself, but having had to downsize my home, I found that it was not the place to have a foundry!


(My addiction to the two stroke has lasted for more than 60 years) - since the days when I first saw Ernst Degner, Horst Fugner and Werner Krumpholz riding MZ's at the Ulster GP! (I must admit my initial interest came via model aircraft engines from the age of fourteen).

However, I had to learn for myself - I didn't share your luck (ie having someone around who understood the two stroke). - the main topic where I lived was, how many cows they owned, the price pigs and cows were fetching at the market, who had the biggest tractor, or moaning about how much tax they paid last year etc. etc.
Not a lot of scope for a budding two stroke engineer! - so I emigrated to New Zealand 54 years ago! ..... but found that they were exactly the same! - however, I decided to stay anyway! - and happy to have done that! - now a New Zealander!

[Pursang]

Hi Dazza the Simpson as posted by you was 1914

Thank-you for pointing that out (so, that's 2 World Wars before Commer), I've swapped the pic!.



There is (to my mind anyway) something wrong in the picture ..... Assuming that crankshaft rotation is clockwise of course, the cranks are clearly not at 180 deg to each other, so the crank controlling the right hand piston has not yet reached the TDC position - so why are both rockers positioned exactly the same - ie at the end of their travel??

This is of course is an OP engine, but it's also a Diesel and Diesels don't figure in the 'clean two stroke' picture these days! (But I may have got it all wrong!)

I think the Patent drawings were more conceptual, rather than actual blue prints. Plus, it's a great way to keep 'Reverse Engineers' on their toes, even 90 years later!:scratch:

Reference to the patent description explains, thusly: https://patents.google.com/patent/US2099371A/en

The throws are so arranged that the opposed pistons in both cylinders move in the same direction, but the throws 28 and 29 controlling the movement of the pistons 19 in the cylinders are disposed approximately 15 degrees back of the throws 27 and 30 so as to effect a phase difference of approximately 15 degrees between the motions of the pistons 19 and 20. In other words, the throws of the crank for operating the pistons controlling the exhaust ports are disposed in advance of the throws for operating the pistons controlling the intake ports, so that the exhaust ports will not only be opened before the intake ports for scavenging purposes, but will also be closed before the latter ports for supercharging purposes. (Thus satisfying Physics & Frits!)

The numbers in the description might be screwy, probably from optical character recognition, when the patent was digitised)

I'm sure one could argue that Diesel & HCCI are just different types of compression ignition engines.:hug:

Here is a pic from end on.

[WilDun]

.................................................. ...........
I'm sure one could argue that Diesel & HCCI are just different types of compression ignition engines.:hug:

Yes but (as I see it) with a couple of subtle differences, ..... Direct injection and particulate matter production! ..... in the diesel!

[Pursang]

Yes but (as I see it) with a couple of subtle differences, ..... Direct injection and particulate matter production! ..... in the diesel!

DME
Dimethyl ether, DME, is a synthetic, gaseous, diesel fuel that results in clean combustion with very little soot and reduced NOx emissions.

Recognized as a second generation Bio Fuel, it can be synthesized from any sort of crap (especially from Crap!)

Can be substituted for propane, in LPG. And, with slight modifications, diesel engines run well & cleanly on DME. It is also a refrigerant (the 1st, back in 1876) and is used in wart 'freeze spray)

At the 2009 European Shell Eco Marathon, an unofficial World Championship for mileage, a vehicle running on 100% dimethyl ether drove 589 km/liter (169.8 cm3 /100 km), fuel equivalent to gasoline with a 50 cm3 displacement 2-stroke engine.

Thanks to Wikipedia for the info: https://en.wikipedia.org/wiki/Dimethyl_ether#cite_note-23

And it has a cool looking molecule:

[WilDun]

DME
Dimethyl ether, DME, is a synthetic, gaseous, diesel fuel that results in clean combustion with very little soot and reduced NOx emissions.

Not sure of course, but I think the other difference between diesel operation and HCCI might be a determining factor as well, ie direct injection which I feel, isn't compatible with HCCI.

[Pursang]

Not sure of course, but I think the other difference between diesel operation and HCCI might be a determining factor as well, ie direct injection which I feel, isn't compatible with HCCI.

Also, the Diesel process runs un-throttled (Power follows Fuel, not air flow) & psuedo stratified, at the injection zone.
HCCI, by its very definition, requires a homogeneous charge.

DME might be the appropriate fuel for Neil's new OP engine, particularly if E85 is no longer an option.
Double up on the Green Credit points (a marketing bonus).

Cheers, Daryl.

[katinas]

TS3 Horizontally Opposed Piston Engine
Rootes Motor Group built an engine for their trucks which was a design loosely based around an original Sulzer Brothers concept,

http://www.oldengine.org/members/diesel/Rootes-ListerTS3/TS35.jpghttps://www.pattakon.com/patop/CommerTS.gif

but why stop there.



Read that one bus driver prefer later type with four stroke, because of much quieter engine.

[WilDun]

Read that one bus driver prefer later type with four stroke, because of much quieter engine.

I remember Neil (Flettner) saying that most of the noise came from the roots type blower - perhaps a turbo instead? which might fit in well with a lack of expansion chamber? - the 3 cylinder layout might be good (interconnected exhaust).
Looks like there will be a lot of jet fuel available in the future too - could that be vapourised (injected?) somewhere else? rather than at the top of the stroke by high pressure injection? (a homogenous mixture is required for petrol/HCCI of course)

So, what I'm asking - is it possible to have diesel operation with Jet Fuel using a fully homogenised (probably heated) charge but without the need for late high pressure direct injection to initiate combustion?

[katinas]

Cummins and Kharkov two stroke Opposite piston engines for tanks
http://www.malyshevplant.com/en/content/6td/
https://www.nationaldefensemagazine.org/articles/2020/2/12/army-charging-ahead-with-advanced-powertrains
https://revivaler.com/vincent-two-stroke-lifeboat-engine/

[katinas]

Same, 5 cylinder 5ТДФ type Opposite Piston engine in both videos. Direct evolution of Junkers Jumbo 205.
Torque at exhaust side crank approx 70 %, intake side 30 %. Engine can work on diesel, kerosene and gasoline Ron 72, just needed to move the knob to another position.
Compression 20.9 (effective 16.5 )
Two piece piston, top made made from heat resistant material and bolt on to the main alloy piston. Idex in scheme 22,
https://www.youtube.com/watch?v=_CGLanOPwnw
https://www.youtube.com/watch?v=gJwnV6MmNbQ

[ceci]

How about some simplicity

https://patents.google.com/patent/US10487777B2/en?oq=10%2c487%2c777

https://patentimages.storage.googleapis.com/ac/5b/3d/0e081f0c46bf8c/US10487777-20191126-D00000.png

[ceci]

How about some simplicity

https://patents.google.com/patent/US10487777B2/en?oq=10%2c487%2c777

https://patentimages.storage.googleapis.com/ac/5b/3d/0e081f0c46bf8c/US10487777-20191126-D00000.png


The two patents are current and effective 2035.
In both I see similarities with Katinas work:
The first patent the crankcase is also fed through the transfer windows (30a-32a).
The second patent has a reed valve controlling the transfer (24b)


https://patents.google.com/patent/US9726070B2/en

https://patentimages.storage.googleapis.com/fc/b7/b4/8db3a2b9071749/US09726070-20170808-D00004.png

[WilDun]

Same, 5 cylinder 5ТДФ type Opposite Piston engine in both videos. Direct evolution of Junkers Jumbo 205.............................................



Well, - like I said about OP, pollution problems over!! :shit: - but let's be positive, if everyone has one, then it won't be noticed! :facepalm:

[Pursang]

.
Makes a Hell of a mess if you blow one up, too!....;)
.
https://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=347129&d=1599242821

[ceci]

I am in doubt as to whether these statements in this patent are true or fake.
If true, why has it not been worked on evolving it?


https://patents.google.com/patent/US4627390A/en?oq=4%2c627%2c390

[ceci]

https://3.bp.blogspot.com/-PmTpX3YiKmo/WxX4UW0ow9I/AAAAAAAAhiU/wrcjbvgrVrcSpBmNf8I_gvS92PQmXuSOwCLcBGAs/s400/1951%2B2%2Bstroke%2BVespa%2B1.JPG

[Flettner]

What are we looking at CECI?
A little more information please.

[ceci]

What are we looking at CECI?
A little more information please.

You've convinced me to go over to the dark side, now I'm intrigued by the opposite piston engines



https://oldmotodude.blogspot.com/2018/06/1951-vespa-opposed-piston-2-stroke.html


http://www.lambretta.it/velo2.php?lingua=ita

http://www.lambretta.it/_img/lotta9.jpg

As we can see, it is 125 with two pistons and if we compare the power figures with that of the garelli 125 with two pistons, it does come out very poor.

[Flettner]

CECI, It certainly apears to be OP but its not Uniflow scavenge. An exhaust port at each end?
I've reviewed this drawing again, now Im not sure what Im looking at.

[WilDun]

Vespa? - Lambretta? but quite a tidy looking motor- for an OP - ie the first photo (if indeed it is an OP and not two engines tacked together for an experiment !)

[OopsClunkThud]

Vespa? - Lambretta? but quite a tidy looking motor- for an OP - ie the first photo (if indeed it is an OP and not two engines tacked together for an experiment !)

Vespa 1951. one off (well two actually) for a streamliner. 125cc set a record of 172km/h. looks like at least one version of the engine was uniflow. I'll dig up a picture from a book

347252

[Flettner]

Thankyou, much easier to see now.

[WilDun]

Does that drawing make sense to you guys? (perhaps I'm a little slow of course!) - but as I see it, - if those are exhaust ports then they sure won't work very well in that position!

[OopsClunkThud]

the pistons are are BDC in the drawing, those two conical ports are piston port intakes. the top view shows the exhaust and transfers better.

[ceci]

I am in doubt as to whether these statements in this patent are true or fake.
If true, why has it not been worked on evolving it?


https://patents.google.com/patent/US4627390A/en?oq=4%2c627%2c390



This is what I think are the answers to the questions I posed:
The patent does not show what make and model of motorcycle they tested (it could possibly be an MZ).
The data is given based on speed, which indicates that this data was possibly in a band of 2450 rpm (in this rpm range, the crankcase is still pumping).
The operation of a standard engine from 1981 is very similar to that of a trial motorcycle (the power in trial bikes has not increased the power from that time to the present), as you can see in the graph of the GasGas TXT gives the 90% of torque before 2000rpm.
The data on the reduction of consumption are true (the mechanism works since the crankcase pumps precompression)
The reason why it did not succeed is that it works at a low rpm, but to reach maximum power more rpm is needed (here the crankcase no longer pumps enough precompression).
I arrived at these beliefs based on data from SAE papers 960365
Diaphragm Fuel Injection System (DFI)
for Stratified-Charging of Small
Two-Stroke Gasoline Engine
https://i.pinimg.com/originals/86/17/18/861718596250454c807600c79dade898.jpg
https://www.dirtrider.com/resizer/OsWPnmlOFR35MdttRbVVGghvtAk=/853x640/cloudfront-us-east-1.images.arcpublishing.com/bonnier/BRF7HNMVGZFQVJBA23C4E773N4.jpg

[WilDun]

the pistons are are BDC in the drawing, those two conical ports are piston port intakes. the top view shows the exhaust and transfers better.

Ok, after enlarging things some more I can now see that, - and BTW it was due to failing eyesight rather than a failing brain! (I hope).:rolleyes:

[ief]

Mind fart, must be a dozen things wrong with it, already thought about/ discussed many times perhaps, will post anyway :)

Ps: Don't mind the details plz.

[Flettner]

Puting some water cooling galleries in, air only case so some cooling will be beneficial. OP uniflow.

[Flettner]

one done, second side in the machine.

[Flettner]

one x water cooled cases.

[trevor amos]

Many decades ago I took a keen interest in Egyptology, and in particular the exploits of the early European explorers tackling the mysteries of the Pyramids.
I`m minded of an opinion which might be attributed to Belzoni or perhaps Champollion, I can`t recall which, or perhaps neither. This quote is from a letter to one of their sponsors lamenting that he has been unable to discover an unviolated royal tomb, ”My dear friend I fear that to be Pyramidially extant is a fallacy in duration”. A goal hoped for but seemingly unattainable.
Whilst being a noble cause I fear the climate change lobby will prevail and our two-stroke engines will be further marginalised and eventually outlawed. Just how “clean” can a clean two stroke engine ever be?
Will there otherwise be a truly viable and commercial engine that will not violate some international emission standard or is the whole matter still, a fallacy in duration?
After saying that, this is an absolutely terrific thread, a whole bunch of skilled, clever people brain storming to a common purpose but with lots of peripheral interest to draw in the inquisitive. One more reason why the whole KB site is the premier exemplar to go to be informed and educated.

Trevor

[Niels Abildgaard]

Many decades ago I took a keen interest in Egyptology, and in particular the exploits of the early European explorers tackling the mysteries of the Pyramids.
I`m minded of an opinion which might be attributed to Belzoni or perhaps Champollion, I can`t recall which, or perhaps neither. This quote is from a letter to one of their sponsors lamenting that he has been unable to discover an unviolated royal tomb, ”My dear friend I fear that to be Pyramidially extant is a fallacy in duration”. A goal hoped for but seemingly unattainable.
Whilst being a noble cause I fear the climate change lobby will prevail and our two-stroke engines will be further marginalised and eventually outlawed. Just how “clean” can a clean two stroke engine ever be?
Will there otherwise be a truly viable and commercial engine that will not violate some international emission standard or is the whole matter still, a fallacy in duration?
After saying that, this is an absolutely terrific thread, a whole bunch of skilled, clever people brain storming to a common purpose but with lots of peripheral interest to draw in the inquisitive. One more reason why the whole KB site is the premier exemplar to go to be informed and educated.

Trevor

The only chance is ligth aircraft propulsion.
One liter of avgas contains one gram of lead that is an absolute no no everywhere else.
Why is this sector not regulated?
Because it is playground for the rich and few.
The electric motors(and generators) to day are so light that combustion engine-generator(s)-propmotor is a possibility.
In that case opposed piston two stroke gas engines make sense.

[Flettner]

Arh, nicely side stepped, ethanol.
Produced in NZ via geothermal and hydro electric, made from a waste product of the dairy industry, a carbon go round. We conveniently ignor deisel trucks picking up the milk or the farm fuel usage, ok��.

Neils, build one.

Im building my convictions, if for no other reason but to have something a little different out on the track and to show it can be done.

Next is to produce an Autogyro powered by an Opposed Piston Uniflow engine, with counter rotating props but deep intetmeshing like a Kmax helicopter rotor system. Compact and easy using the two joining idler gears.
Out of phase crank forces taken up between the crank throws themselves with each crank assembly controlling an exhaust and and inlet piston. Gears just join the cranks, pistons fire together so forces loading and unloading on the crank and gear assembly are equal. 25 years ago Neils.

[WilDun]

Arh, nicely side stepped, ethanol.
Produced in NZ via geothermal and hydro electric, made from a waste product of the dairy industry, a carbon go round. We conveniently ignor deisel trucks picking up the milk or the farm fuel usage, ok��.

Neils, build one.

Im building my convictions, if for no other reason but to have something a little different out on the track and to show it can be done.

Next is to produce an Autogyro powered by an Opposed Piston Uniflow engine, with counter rotating props but deep intermeshing like a Kmax helicopter rotor system. Compact and easy using the two joining idler gears.
Out of phase crank forces taken up between the crank throws themselves with each crank assembly controlling an exhaust and and inlet piston. Gears just join the cranks, pistons fire together so forces loading and unloading on the crank and gear assembly are equal. 25 years ago Neils.

Guess that mostly makes sense, especially the use of Ethanol (in NZ anyway!) - but layout maybe not ideal for compactness in a motorcycle, ( but then the old Boxer BMW survived didn't it?) - but I guess you may have a few tricks up your sleeve in that area!
No doubt your fuel injection system will make quite an improvement to earlier designs in this area! - especially good in the balance area! - cheapness of manufacture! (no head manufacture or sealing problems), waiting to see combustion chamber design, - also waiting to understand the scavenging part/exhaust design! ..... anyway keep going and it'll all unfold.
:niceone:

[Pursang]

- but layout maybe not ideal for compactness in a motorcycle, ( but then the old Boxer BMW survived didn't it?) - but I guess you may have a few tricks up your sleeve in that area!

Neil's prototype is being fitted in a YZ250 frame. A structure, by it's purpose, about as compact as possible for the task.

The prototype engine isn't really being optimised for the frame (or the frame for the engine).

This quick 'paint job' shows the gearbox housing reoriented slightly and the engine lowered to the frame rails.
Plenty of room up top, he could easily extend the stroke(s) for 300-450cc if needed.

If the frame brace did interfere, the top crankcase could be cast with lugs to form a bolt-in brace.

For the ultimate in compactness, cast the steering head as part of the top case.

Cheers, Daryl.

[Niels Abildgaard]

Arh, nicely side stepped, ethanol.


Neils, build one.



Ethanol has 23 MJ energy per kg and petrol has 42.
Apart from modelaircrafts and 5 minute man carrying stunts ethanol is not a good aircraft fuel.
The rate of dead people from using amateur flying gear is high and I am amateur so no thank You.

[Flettner]

Neils prototype is being fitted in a YZ250 frame. A structure, by it's purpose, about as compact as possible for the task.

The prototype engine isn't really being optimised for the frame (or the frame for the engine).

This quick 'paint job' shows the gearbox housing reoriented slightly and the engine lowered to the frame rails.
Plenty of room up top, he could easily extend the stroke(s) for 300-450cc if needed.

If the frame brace did interfere, the top crankcase could be cast with lugs to form a bolt-in brace.

For the ultimate in compactness, cast the steering head as part of the top case.

Cheers, Daryl.

Daryl, yes this uniflow setup Im building is just got to be good enough to run and test. If I got to build another one the long engine would lay down with the gearbox wrapped around it.
One issue I do have is I dont want to cut this frame at all, its not mine and may ultimately need to go back to being a 250F again.
Yes the engine is long and more difficult to house but do remember for a given cc the two cranks are smaller and no need for an added balance shaft. Also no head, so some size advantages.

[Flettner]

Ethanol has 23 MJ energy per kg and petrol has 42.
Apart from modelaircrafts and 5 minute man carrying stunts ethanol is not a good aircraft fuel.
The rate of dead people from using amateur flying gear is high and I am amateur so no thank You.


https://youtu.be/96XnJh98LqQ
Neils, you better tell this guy he shouldn't be flying then.

Neils, you could just gound test your engine, you dont have to fly it, get stuck in and build it.

[ken seeber]

Have a look at this, a 4 stroke plane engine

https://www.bydanjohnson.com/welcome-hybird-new-four-stroke-engine-for-light-aircraft-replaces-hks/

The OP with 2 props would be a lot nicer.


interesting that there is no emission regulation for planes in terms of lead....

[Flettner]

Have a look at this, a 4 stroke plane engine

https://www.bydanjohnson.com/welcome-hybird-new-four-stroke-engine-for-light-aircraft-replaces-hks/

The OP with 2 props would be a lot nicer.


interesting that there is no emission regulation for planes in terms of lead....

I dont much like the crappy belt drive.

All old aviation engines still need lead, even if it is now what they call low lead. Best would be to just get rid of all those old crappy direct air cooled dinosaurs aviation engines. Imagine the law suites.

[ceci]

This can be considered a Ryger from the past?.
The crankcase is insulated
I think the pump performance is even more effective

https://patents.google.com/patent/US961315?oq=two+stroke+engine

https://patentimages.storage.googleapis.com/30/35/62/e3ed0c7a2af466/US961315-drawings-page-1.png

[WilDun]

Saw that one many years ago, and was quite impressed at the time, even though it was done in 1908!
The last name is a bit suspicious though! .... "De Lostalot"! ?

[Frits Overmars]

Saw that one many years ago, and was quite impressed at the time, even though it was done in 1908!
The last name is a bit suspicious though! .... "De Lostalot"! ?Impoverished French nobility, no doubt :msn-wink:.

[katinas]

Another similar solution, but with "plate valve" intake.

[ceci]

Another similar solution, but with "plate valve" intake.

What has more friction, plate valve or a rotary valve?

[WilDun]

Another similar solution, but with "plate valve" intake.

You know, I really don't think we have evolved much since those days (in the IC world) - there were so many very good ideas which were dismissed as being ridiculous!
BTW, I would like to see that mystery "X" engine, (part of which is just showing, next to the pic of the plate valve).

[katinas]

"X" engine is Davi concept from sixties for Pontiac. In second photo Reid 598 cc 31kw 5000rpm.

Ceci, downside of "plate on rod concept", apart of additional moving parts, is that this not eliminated the oil for main piston. With Ryger, just very small amount of oil is needed, as there is no forced contact between main piston and cylinder.

[katinas]

Little work on KTM SX 300 with Flettners TPI type. The owner only request to replace the piston, but we could not miss this opportunity.
Only minor corrections, squish from original 1.7 mm to 1 mm, slightly radiused piston, corrected and reshaped combustion chamber to restore compression. We didn't tell the owner anything about it, just wanted to use him as a “live dyno”. Later he called in doubt is it really his engine. At the bottom its like a 450 four stroke with two stroke top end.
It looks like with more changes on this engine, could be very interesting results. Very nice back flow restriction space, between crank and reed room floor.

[ceci]

Ceci, downside of "plate on rod concept", apart of additional moving parts, is that this not eliminated the oil for main piston. With Ryger, just very small amount of oil is needed, as there is no forced contact between main piston and cylinder.

thanks i did not take into account the lateral forces of the crank thrust

https://www.researchgate.net/publication/282476698/figure/fig7/AS:668371238526987@1536363529791/Connecting-rod-and-force-analysis-on-crank-pin-and-liner-a-Load-schematic-of-the.ppm

[WilDun]

There are several other ways of translating liner force to rotating force - With a piston engine this is always necessary, so the piston (with the normal crank arrangement), as well as having to translate the pressure in the cylinder into (linear) force, it is also being used as a crosshead to translate that linear force into rotating force! - I think that the piston can be relieved of that extra duty (and there are several ways of doing this) then it can be lightweight and with no side forces acting on it, will require much less lubrication.
Even the Ryger system has it's problems in this area.

The Ryger (I believe) will still have problems trying to maintain a good seal while trying to deal with sidethrust in the narrow part of the piston.

The rotary engine (not only the Wankel) will make these problems go away of course, but will bring some other major problems of its own!

The "free piston" engine did look promising but obviously, for some reason it hasn't actually got it's act together as yet! - if it did come to pass, then obviously it would be most useful with a "Hybrid" type transmission.

I don't believe that EV (like most other things) is the total answer, but they are going to be just that in the cities.
In 'wheeled' vehicles elsewhere, hybrid style transmission will probably be used a lot and if the two stroke can survive, it will have to be adapted to this mode of transmission.
(competition is a totally separate issue, but will generally follow the "real world" trends).

These are only my suggestions of course and I could be wrong - but, I just feel that it's the only real hope for a road going two stroke!

[ceci]

You know, I really don't think we have evolved much since those days (in the IC world) - there were so many very good ideas which were dismissed as being ridiculous!


This is one of those ridiculous ideas

https://patents.google.com/patent/US1314561?oq=diaphragm+pump+fuel+engine

https://patentimages.storage.googleapis.com/a7/8b/39/98b52b372703b7/US1314561-drawings-page-3.png

[WilDun]

........ ridiculous ideas .......


What amazes me is that even though they invented all those great engines, ........ they still hadn't even thought of Phillips Head screws or Allen screws/bolts!

[Norman]

I find it interesting that Lennarth Zander, with an ongoing history as one of the leading powertrain engineers at Volvo Cars and Scania CV, found it worthwhile to consider the two-stroke as a range extender for BEV/HEV. And yes, he does have a passion for two strokes. Attached article from a presentation for ongoing projects 2019 at Chalmers University of Technology, Sweden.

[Vannik]

Lennarth Zander also wrote a nice book " Internal Combustion Engine: Gasexchange and Boosting"

[Vannik]

What amazes me is that even though they invented all those great engines, ........ they still hadn't even thought of Phillips Head screws or Allen screws/bolts!

NASA's attempt:

https://www.techbriefs.com/component/content/article/tb/pub/techbriefs/mechanics-and-machinery/3135

[ceci]

NASA's attempt:

https://www.techbriefs.com/component/content/article/tb/pub/techbriefs/mechanics-and-machinery/3135



Covid and other health problems have given me time, too much, so much that I get bored.
And this has made me discover that there is nothing new or improved.
Example: https://journals.sagepub.com/doi/10.1243/PIME_PROC_1949_161_024_02

[Frits Overmars]

Covid and other health problems have given me time, too much, so much that I get bored. And this has made me discover that there is nothing new or improved.
Example: https://journals.sagepub.com/doi/10.1243/PIME_PROC_1949_161_024_02That would have been about fifteen years before Gordon Blair revealed a similar system at Queens University Belfast....

[lohring]

This is a paper on a system I could consider building. I'm sure it isn't as good as Blair's method, but I'm more interested in visualization to get a general idea of what's happening. Hopefully, 3D printing would make the transfers rough enough to avoid laminar flow.

Lohring Miller

347461

[Vannik]

That would have been about fifteen years before Gordon Blair revealed a similar system at Queens University Belfast....

Blair was quite taken aback when he discovered Sammons' idea predates his was not only identical to his but predates it by quite a bit. Once he discovered it he gave credit to Sammons. Sammons first published it in 1949 and Blair developed his in the early 80's, so more like it predates his by 30+years.

[ceci]

Blair was quite taken aback when he discovered Sammons' idea predates his was not only identical to his but predates it by quite a bit. Once he discovered it he gave credit to Sammons. Sammons first published it in 1949 and Blair developed his in the early 80's, so more like it predates his by 30+years.


Result of this research work, is this patent

http://patentimages.storage.googleapis.com/pdfs/US2573989.pdf

[Flettner]

gearbox is in and bottom crankshaft.

[Pursang]

gearbox is in and bottom crankshaft.

:2thumbsup

cheers, Daryl.

[Norman]

gearbox is in and bottom crankshaft.

:clap:

Looks good

[ceci]

The decade of the 90 is the one that more patents have been found for 2S, most are from Stihl and Bosch, so there are also many others dedicated to stratified scavenging

[ken seeber]

The decade of the 90 is the one that more patents have been found for 2S, most are from Stihl and Bosch, so there are also many others dedicated to stratified scavenging

What a pisser, the dirty bastards...……as always, some old mate somewhere has done it before...just to add insult to injury, I have been using a Walbro carby on my test rig… Wonder if they actually had engine running? Good on them though for thinking about clean 2 strokes.
Oh well, will keep trying, have had some interruptions of late. Have to get some more valves wire cut before my mate finishes work at the end of November,

347594

[ken seeber]

Happy reading if this pdf works..

347598

[WilDun]

What a pisser, the dirty bastards...…… Good on them though for thinking about clean 2 strokes.
Oh well, will keep trying,
347594

Ken,
That's the way. don't let the bastards wear you down! - see it all through + a bit more! :niceone:

[ken seeber]

They reckon that this made a difference, looks like some proprietary system, maybe something that TZee was playing with. Constant sped and load, so no transient complications.

https://www.youtube.com/watch?v=0YnlBI5U1XI&feature=emb_logo

[Flettner]

looks like a shit little motor but I guess you cant argue with their record.

[lohring]

Careful, that's one of the motors we race. Of course ours are water cooled with a tuned pipe and port mods. They're good for around 7 hp at 16,000 rpm. That one is probably lucky to have 4 1/2 hp. I wonder whether its fuel consumption per hp is better. Of course I wouldn't bet on one of our race engines lasting 10 hours at full throttle.

Lohring Miller

[Flettner]

Yes 10 hours is a lot under full load.
Perhaps they need an OP engine.

[lohring]

Absolutely

Lohring Miller

[ceci]

Curiosities of life ADOLF SCHNUERLE in 1932 changed the cross scavenging, abandoned the stratified uniflow scavenging 1928.
The current trends are to abandon scavenging SCHNUERLE and return to uniflow scavenging

https://worldwide.espacenet.com/patent/search/family/007440828/publication/DE463019C?q=pn%3DDE463019C

https://worldwide.espacenet.com/patent/search/family/005690310/publication/CH172816A?q=pn%3DCH172816A

[ceci]

Since its invention by Sir Dugald Clerk the two stroke engine (scavenging uniflow) brought the short circuit and the loss of hydrocarbons through the exhaust.
With the invention of patent DE463019C these defects in this type of two stroke engine design were solved.
With the invention crankcase as a charging pump by Joseph Day, the two stroke engine is simplified to the detriment of clean advances
And that detriment of the clean two stroke engine increases as new inventions appear which are developed only to obtain more HP
The opposed-piston is one more of the inventions that the only thing that has been sought is to obtain more HP without taking into consideration the clean two stroke engine (DKW / Kurt Kuhnke KS-1, 1951 Vespa opposed-piston 2-stroke.)
When recent CFD simulations show that the opposed-piston could perform stratified scavenging and advance the clean two stroke engine
there will one day be a clean two stroke engine or we are only interested in making it the most powerful

[ceci]

convoluted two stroke engine Opposed piston

https://worldwide.espacenet.com/patent/search/family/027317799/publication/DE2850041A1?q=pn%3DDE2850041A1

[Flettner]

convoluted two stroke engine Opposed piston

https://worldwide.espacenet.com/patent/search/family/027317799/publication/DE2850041A1?q=pn%3DDE2850041A1

Strikingly similar.

[Pursang]

Strikingly similar.

I can see the title of the the Text Book!

Advanced 2 Stroke Engine Design - The Theory and The Practice. (with colour plates)

Keep up the great work Neil!!

Cheers, Daryl.

[Haufen]

Free webinar on a DI two-stroke opposed piston research engine

https://events.imeche.org/ViewEvent?e=7213

although it might be in the middle of the night for some of you.



Start time:
12:00 London

[Stefan38]

That would have been about fifteen years before Gordon Blair revealed a similar system at Queens University Belfast....

What ever happened to Harry from Ryger? I have a personal interest and trying to find out what happened with him or where he is operating from.

[Haufen]

Free webinar on a DI two-stroke opposed piston research engine

https://events.imeche.org/ViewEvent?e=7213

although it might be in the middle of the night for some of you.


for all interested: the webinar is about to start (8min).


Edit: turns out the webinar can also be watched afterwards and downloaded as well


http://email.mail.workcastevents.com/c/eJw9jssOgjAQRb-mLMm8Oi2LLnzxH0OtYhQ1QOT3RU1M7urc5OQck8VYqksiIEBCQ AYUrbGGA7BH326brexaRScw2OVWL4_xmm2ay6vc56nOj6HqkwB 2wYqaaNc0OQuodZitnDDqKVh1S_08PyfHG0ftumVZ_qaP40O5z U-7Ot57IB9VRJCIgwRH-jsiUQiegYM2DBGrMZ3L2Bc7rnXnb97qegPwHjyq

[Norman]

Petrol by converting CO2 taken from the atmosphere.

I do not think that BMW this year invested $12,7 million in Prometheus just for fun.

https://prometheusfuels.com/

[Flettner]

Im hanging my hat on this.

Problem though is the amount of energy required to process, you dont get something for nothing. But then capturing suns energy then storing in a battery is is hardly very efficent either.

[Norman]

Im hanging my hat on this.

Problem though is the amount of energy required to process, you dont get something for nothing. But then capturing suns energy then storing in a battery is is hardly very efficent either.

Yes..I read in Motortrend that it is about ~60% electrochemical efficiency (maybe can be optimized as everything else) you need 61 KWh electrical energy to get 36,6 kWh fuel. And of course, using renewable energy sources is in the concept as well as it is for electrical cars.

If this works, without to much drawbacks, Greta will like it. And she will perhaps let us continue using our ICE:s. BTW, she appeared in a BMW "ad" a couple of days ago saying BMW is the most environmental friendly car company..

Cheap electrical power is necessary but should be possible under contract at, what, 0,02-0,04 EUR/kWh? Perfect to use surplus electrical power also.

[breezy]

Free webinar on a DI two-stroke opposed piston research engine

https://events.imeche.org/ViewEvent?e=7213

although it might be in the middle of the night for some of you.

well, got to see this and it enlightened me on the free piston opposed set up....always wondered how a free piston could move something... didn't know that its first combustion stroke is initiated by elastictrickery and it produces no torque and is basically an electrical generator.....but then i don't get out much these days:rolleyes:

[Pursang]

Just found this video, while looking for something else.

Lots of thoughts for adjustable two stoke exhaust resonant tuning, using temperature management and/or mechanical or electrical controlled diaphragms.


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

cheers, Daryl.

[Haufen]

Just read that the engine from the webinar above won 2.6m GBP in funding to go into the next stage (performance validation prototype). It will be combined with passive pre-chamber ignition (like current F1 engines) which should improve efficiency even more.

In times where you can read news about automotive OEMs announcing end dates for combustion engines weekly, that's really good news for petrolheads. And it's a two-stroke! Who would have imagined that :yes:

https://www.linkedin.com/pulse/libertine-wins-26m-uk-funding-decarbonise-heavy-duty-mahle-cockerill/


this one:

Free webinar on a DI two-stroke opposed piston research engine

https://events.imeche.org/ViewEvent?e=7213

although it might be in the middle of the night for some of you.

[Pursang]

Just read that the engine from the webinar above won 2.6m GBP in funding to go into the next stage (performance validation prototype). It will be combined with passive pre-chamber ignition (like current F1 engines) which should improve efficiency even more.

In times where you can read news about automotive OEMs announcing end dates for combustion engines weekly, that's really good news for petrolheads. And it's a two-stroke! Who would have imagined that :yes:

The fact that it is a "real world" test by a major transport company is promising.
New innovations only tend to survive when they are considered an improvement by Users who's own money and business success is on the line.

Cheers, Daryl.

[Flettner]

Time to have another hack at the HCCI engine.
No electronics or sparkplug.
No reed or rotary valve
No transfers as we know them, apart from a boost port.
Carburetor throttling/fueling. ceci might appreciate this��
Cast iron bore, because its cost effective.

[F5 Dave]

Went for a ride today with a mate with MC21. Maybe not that clean, but increasingly cool. Smells good.

Need to finish my 500.

Jesus that will give James Shaw coniptions

[ken seeber]

It's a 2 stroke....:first::first::first:

https://newatlas.com/automotive/aquarius-single-piston-hydrogen-engine/

[ceci]

Time to have another hack at the HCCI engine.
No electronics or sparkplug.
No reed or rotary valve
No transfers as we know them, apart from a boost port.
Carburetor throttling/fueling. ceci might appreciate this��
Cast iron bore, because its cost effective.

Hi Flettner.
If you are asking me.
I honestly cannot guess why it is profitable.
If I am wrong and it is not me who is asking, excuse me

[Flettner]

Ceci, the plan is to run the A ports direct from atmosphere, no fuel.
B ports have a carburetor (x2) attached, drawing direct from atmosphere. A ports never communicate with the crankcase, B ports, with the carburetors, do communicate with the crankcase when the piston is up (piston port ), as well as direct to the cylinder when the piston is down.
Crankcase feeds the boost ports (x2) so as to get some actual pumping.

In the head will be my short stroke piston running at x2 engine speed, so as to get compression ignition at the right time.

The idea behind this is to hopefully get some TPI like cylinder fill and be able to throttle the HCCI process all with no electronics. For a start anyway, I will soon add some electronic complication Im sure.

Ceci, the lack of electronics I thought you might appreciate.

[ceci]

Ceci, the plan is to run the A ports direct from atmosphere, no fuel.
B ports have a carburetor (x2) attached, drawing direct from atmosphere. A ports never communicate with the crankcase, B ports, with the carburetors, do communicate with the crankcase when the piston is up (piston port ), as well as direct to the cylinder when the piston is down.
Crankcase feeds the boost ports (x2) so as to get some actual pumping.

In the head will be my short stroke piston running at x2 engine speed, so as to get compression ignition at the right time.

The idea behind this is to hopefully get some TPI like cylinder fill and be able to throttle the HCCI process all with no electronics. For a start anyway, I will soon add some electronic complication Im sure.

Ceci, the lack of electronics I thought you might appreciate.

Hi Flettner
Good combination, Multi-Layer Stratified (MuLS) and HCCI.
A tuned pipe is essential to fill the A ports.
I'm intrigued by what the crankcase-to-cylinder transfer setup will look like.
Thanks for sharing

[Flettner]

There is only one (x2 side by side) boost port, nothing else.

The x2 speed piston in the head should give some intetesting results, with volume changes at various points of the engine cycle. Should make the engine ingest more fuel air and help draw energy from expansion.
But this piston does not figure in the rated engine capacity, of the main piston. When the main piston is at TDC so is the small piston, when the main piston is at BDC, so again is the small piston at its TDC. So if the main piston sweeps 100cc the small piston has no relevance, according to how swept volume calculations are done.
Yes it relies heavily on a tuned pipe, perhaps even a variable one.

[ceci]

There is only one (x2 side by side) boost port, nothing else.

The x2 speed piston in the head should give some intetesting results, with volume changes at various points of the engine cycle. Should make the engine ingest more fuel air and help draw energy from expansion.
But this piston does not figure in the rated engine capacity, of the main piston. When the main piston is at TDC so is the small piston, when the main piston is at BDC, so again is the small piston at its TDC. So if the main piston sweeps 100cc the small piston has no relevance, according to how swept volume calculations are done.
Yes it relies heavily on a tuned pipe, perhaps even a variable one.

Unfortunately my mind is very limited and I cannot remember what name has a theory of cylinder filling which occurs due to the contractions or fluctuations of the cylinder, and not due to the pumping of the crankcase.
In your case the secondary piston would do a similar function.
Analyzing it in detail, the movement of the head piston in its second stroke per cycle has vast benefits, it can increase the effect of the negative wave of the exhaust and favor the cancellation of the mixture return to the crankcase.

[ceci]

I know that in this group there are people who know what this theory is called, which what it says is that the cylinder works like a lung "contracting and expanding"

[ceci]

I am an impatient person, excuse me for my curiosity.
You say that you will use carburettors (x2), these carburettors are standard (specific for stratified scavenging) or you plan to modify them a few simple ones.
Taking into account that the displacement is 100cc you can use two of these types
https://ueeshop.ly200-cdn.com/u_file/UPAQ/UPAQ926/2105/products/09/bc91703c74.jpg.500x500.jpg
https://www.walbro.com/wp-content/uploads/2015/12/Stratified-Scavenge-Diaphragm-Carburetors.jpg

[Flettner]

Im just using two mikuni carburetors, 16 bore I think. They will feed the two B ports, one each.
Because I have them in my shop, free.

[ceci]

Im just using two mikuni carburetors, 16 bore I think. They will feed the two B ports, one each.
Because I have them in my shop, free.




And how do you plan to control the passage of ports A.
Sorry for my curiosity

[Flettner]

I dont, air only.

[Grumph]

And how do you plan to control the passage of ports A.
Sorry for my curiosity

I think he means how are you going to throttle the air intake.

Those carbs are trick. Linked fuel and air throttles.

[Flettner]

The B ports are throttled, with carburetors, they feed the cylinder direct and the crankcase also.
A ports are just air, no throttling, just holes with a short tube to a belmouth. My HCCI seems to run like a diesel with load being controlled by fuel only. The carburetors, crank case and boost ports will take care of that at low speed, pipe will take overall gas flow control at high speed.
Who knows for sure? I want to find out hence the experimental build.
I have changed the head design (high speed piston) from the original experiments, should give more control on combustion.

[ceci]

The more details I get to know about his project, the more it resembles Tomio Iwai 1978 at the base.
Of course, they also have clear differences such as: the non-throttling of the air inlet in ports A, introducing the mixture through ports B and not through A, and the use of HCCI technology, inlet port to the cylinder and not to the crankcase

[Flettner]

The more details I get to know about his project, the more it resembles Tomio Iwai 1978 at the base.
Of course, they also have clear differences such as: the non-throttling of the air inlet in ports A, introducing the mixture through ports B and not through A, and the use of HCCI technology.

Interesting.

[ceci]

I was wrong, Tomio Iwai is not multi-ports

[ceci]

the insides of the HCCI head, I guess what you would expect to see. 16mm stroke


Let me put you out of your misery Neil :msn-wink:.

Will, here is some basic explanation, leaving the phase difference between the main crank at TDC and the small crank at TDC aside for now.

When the main piston is at its BDC, the small piston is at its TDC.

When the main crank turns 90°, the main piston is about half-way up, about to close the exhaust, and the small crank has turned 180°, so the small piston is at BDC.

Another 90°-turn for the main crank and another 180°-turn for the small crank, and the main piston is at its TDC, and the small piston is also at its TDC.

Below is a little program you can play with, provided you use Win98 (on some computers it will also run under Win XP) or a Win98-emulator.

335269

Hi Flettner.

It's just a suggestion. Since you have quite a bit of experience in sleeve valve motors and HCCI, why don't you try to put the two techniques together.

The suggestion that I make is that you use a sleeve valve in the head, in this case it would be similar or seem to this one: "Rotating Cylinder Valve (RCV) engine".

Why use that valve, to take advantage of the pumping of the head crankcase.

You tell us that the stroke is 16mm, taking into account that the diameter is 50mm, the displaced volume is 31cc.
Actually it would be 62cc since it would have 2 displacements.

When both pistons are at TDC and the main crank makes a 90º turn, we already know that the small one has made a 180º turn, which has made a compression in the head case "corresponding to those 31cc" (that compression would be stored in a plenum which would be controlled by the sleeve valve).

When the main piston is in BDC, the small one is in TDC and the main crank makes a 90º turn, we already know that the small one has made a 180º turn with which it has made a compression in the head case "corresponding to those 31cc" ( This would be the second compression and this, like the previous one, would also be stored in another plenum separate from the previous one).

Now we only need to release the mixture that we have stored in the plenums, that would be in the 90º that we have left to reach the TDC and that in turn the small piston also goes to TDC, it is in that section when the sleeve valve to to release it "as long as the trapped mixture is at a higher pressure than that in the cylinder"

[ceci]

Of course, it would not be to transform your HCCI engine into an OP engine, it is true that they have parts in common "both engines take advantage of the pumping of the two crankcases", but the differences are in the scavenging mode, since it would continue to maintain the cross flow in uniflow place.
It's just another way to perform a stratified scavenging on your HCCI engine.

[Flettner]

The trouble with sleeve valves is you need a lot of oil, to help it transfer heat.

[ceci]

The trouble with sleeve valves is you need a lot of oil, to help it transfer heat.

Fortunately you know the three techniques that come together in this suggestion (HCCI, OP and SLEEVE VALVE) and you know where the fault is that makes it disposable

[ceci]

I thought that the mixture could act as a coolant for the valve sleeve, but unevenly, not in the same way throughout the sleeve since there may be areas where the outer zone of the sleeve does not come into contact with the mixture

[Haufen]

Euro 5 two-stroke with direct injection:

https://www.visordown.com/news/new-bikes/langen-two-stroke-gains-euro-5-certification-heres-how

I am, however, unable to find the injectors for the direct injection in the pictures. So might be "just" crankcase or throttle body fuel injection after all.

On their homepage it says injection without further details.

https://langenmotorcycles.co.uk/

[Flettner]

Yeah, dosent look very Euro5.
Smoke bellowing out the back
Maybe Euro5 is allowed good smelling twostroke smoke?

[ceci]

https://worldwide.espacenet.com/patent/search/family/064270926/publication/EP3695104A1?q=pn%3DEP3695104A1



https://patentimages.storage.googleapis.com/b3/55/6b/dcfb7aedd017cf/WO2019073448A1.pdf

[ceci]

A year ago I indicated a possible solution for the TPI system to be imposed on the use of the carburetor, at more economical levels and thus be more affordable for much of the world.
In that line I tried to create something that corresponded to what was indicated and what I show you is part of it.
It is a type of pumping that is only possible in the 2S and that would never work in a 4S.
The operation is simple, at the cost of two pumps: a vacuum driven by the crankcase and the other by a plunger driven by combustion in the cylinder.

Image 2 shows the inputs and outputs of the two pumps and the description of the operation is:
1 crankcase vacuum
2 empty pump filling
3 emptying pump vacuum
4 high pressure pump filling
5 plunger impulse input
6 emptying high pressure pump

images 3y4:
control mechanism of quantity to be pumped to the injectors


image 5 description of the operation of the bypass valves in the sections:
1 filling from the tank
2 pumping to the high pressure pump
3 return to deposit
4 high pressure pump filling
5 pumping to injectors.
Valves 3-4-5 must have special characteristics regarding the opening pressure:
valve 3 must have an opening pressure higher than valve 4 and lower than valve 5

This design is for 50cc motorcycles

[ceci]

Yes, it is a proposal of a type of pump that in production costs may not be lower than an electric or mechanical pump operated by cam.
But if it has a lower operating cost since it does not use electrical energy or kinetic energy to function.
The use of this type of pump in comparison with the carburetor would be more the manufacturing cost, but it would share with the carburetor the fact of not consuming energy created by the engine for its operation.

[Vannik]

https://www.autoevolution.com/news/examining-the-low-emission-106-liter-opposed-piston-engine-from-achates-power-170377.html

[ceci]

Yamaha tpi ?

[ken seeber]

Ceci,
Well it does discharge into the transfer passage, but not against the net air flow direction, but that’s where there’s any similarity.
It’s interesting though in terms of the fuel metering rate, using the pressure extremes within the crankcase to control the stroke of the plunger pump, hence fuel per cycle (fpc) delivery. Wonder it they ever got it running?

[ceci]

Ceci,
Well it does discharge into the transfer passage, but not against the net air flow direction, but that’s where there’s any similarity.
It’s interesting though in terms of the fuel metering rate, using the pressure extremes within the crankcase to control the stroke of the plunger pump, hence fuel per cycle (fpc) delivery. Wonder it they ever got it running?


Hi Ken.
This is one of many attempts "if you check you will see all the others (Boch, Stihl, Martin Clerch and a few others)" to create an injection using the maximum pressure of the crankcase.
You know that it is not enough pressure that is created, when you collaborated with the creation of the DICTEH in ORBITAL, they decided to use an auxiliary compressor instead of using it as if they do it in the IAPAC in IFP.
The crankcase pressure is not valid, instead we can use the cylinder pressure (I already showed an attempt that dates from 1919), this other one that I show you has as a reference that of 1919, it can be used in a single cylinder engine, injection in transfer pasage.

https://patentimages.storage.googleapis.com/68/ae/60/3029c3e952877c/US3123061-drawings-page-1.png

[Flettner]

Back on the bench.

[Muhr]

Yamaha tpi ?

why not an electromagnet like https://m.youtube.com/watch?v=bpA1xwVWJ-M
or a cam lobe on the web like an old diesel

[speedpro]

Yamaha tpi ?

If port 25 had CO2 fed to it controlled by an ECU, like they do to wastegates on high performance turbo engines, I can see it working quite well. TZs Arduino controlling a pair of PWM valves, one in and one out, would probably do it.

[ceci]

why not an electromagnet like https://m.youtube.com/watch?v=bpA1xwVWJ-M
l

That pumping method reminded me of my youth, when I stole fuel from my father's car, for my motorcycle.
I don't see it as an injection, I see it more as a carburetor with fuel supply control

https://www.wikihow.com/images/thumb/9/96/Siphon-Gas-Step-6-Version-2.jpg/v4-728px-Siphon-Gas-Step-6-Version-2.jpg.webp

[ceci]

If port 25 had CO2 fed to it controlled by an ECU, like they do to wastegates on high performance turbo engines, I can see it working quite well. TZs Arduino controlling a pair of PWM valves, one in and one out, would probably do it.

With this approach you do not need PWM valves, just turn the pump and relocate it, in addition to the passage and control valves.
As you can see now, cavity 13 is not connected by passage 25 but by a direct one from the cylinder and above the exhaust port 11.
Passage 25 is now for supplying control pressure in cavity 14 to control the displacement of plunger 15.
Based on the theory of TZ350, with increasing RPM passage 25 would supply less pressure to cavity 13




If the pipe is not sucking that hard you will have a higher residual pressure left in the crankcase. That explains why at idle and low throttle at low revs the crankcase pressure is higher than when the throttle is wide open and the motor is singing on the pipe. With high crankcase pressure exhaust gas pollution explains why when the throttle is closed the motor slows down to an idle.

At idle the motor is running on a very small amount of fresh air mixed with a lot of pollution that has back flowed from the exhaust. I am not sure if the crankcase is full of pollution or its full of clean mixture and only a small amount is being transferred to a cylinder full of un scavenged pollution, maybe a bit of both so the story is not completely told yet.

[ceci]

The important thing is not when you inject.
The important thing is how and where it is injected.
The injection would begin when the exhaust port 11 was discovered.
It is injected into the transfer galleries B, creating a scavenger stratified .
Injecting with more pressure creates a better spray

[ceci]

SORRY, for having done such a desecration by suggesting such a modification of a Yamaha project.
I know I have played with the two magic words that attract your attention "YAMAHA" "TPI" to show you something nonsensical

[Flettner]

Im just waiting for lockdown to finish so I can go out and do some more riding / tuning, ripping around the back yard is fun but worthless.
Useless Chinese volt meter stopped working almost immediately, should have know better I guess.

[ceci]

This is "yamaha" Minarelli, but it is not TPI.
Another like Vins, injection to the crankcase.
Along with Athena, Italians are not convinced by the TPI
https://enduro21.com/images/2021/november-2021/minarelli-2t-fuel-injected-engine/motori_minarelli_300_2t_fi_eicma2021__0347.jpg
https://enduro21.com/images/2021/november-2021/minarelli-2t-fuel-injected-engine/motori_minarelli_300_2t_fi_eicma2021__0356.jpg
https://enduro21.com/images/2021/november-2021/minarelli-2t-fuel-injected-engine/motori_minarelli_300_2t_fi_eicma2021__0341.jpg

[TZ350]

This is "yamaha" Minarelli, but it is not TPI. Italians are not convinced by the TPI

Only one injector. I would love to know more about the max power@rpm and torque@rpm.

[ceci]

Only one injector. I would love to know more about the max power@rpm and torque@rpm.

the same as with carburetor

[TZ350]

the same as with carburetor

Ok, did a Google search but did not really know what I am looking for. Please help me out here and post the specs if you have them.

[ceci]

Ok, did a Google search but did not really know what I am looking for. Please help me out here and post the specs if you have them.

The first thing is to understand that they intend to sell, they do not want to sell us anti-pollution, they do not want to sell us power either.
What do they want to sell, comfort at a low price.
Convenience: it is not having to have knowledge to be able to regulate the carburetion since it is done by software from your smartphone.
Low price, by using an existing motor and only slightly converting it.
This type of injection is not new, the engineer who created OSSA TRi, proposed it for the GASGAS "trial" and other brands.
He uses the principle of Ockham's razor (the cheapest is the best in equality of operation)
https://todotrial.com/Fotos/noticias2013/GasGasInjection-Xiu1.jpg

[mradil606]

2 strokes engines are now almost no use but dirt bikes are still made with this engine, You may check out the best dirt bike helmet under 200 (https://dirtbikehelmetshub.com/best-dirt-bike-helmets-under-200/) to secure your head during the drive.

[ken seeber]

2 strokes engines are now almost no use but dirt bikes are still made with this engine, You may check out the best dirt bike helmet under 200 (https://dirtbikehelmetshub.com/best-dirt-bike-helmets-under-200/) to secure your head during the drive.

What's the go here ?? Could you please explain what you mean re 2 strokes and, IMPORTANTLY, are you advertising helmets? Certainly not appropriate here...

[husaberg]

What's the go here ?? Could you please explain what you mean re 2 strokes and, IMPORTANTLY, are you advertising helmets? Certainly not appropriate here...
You need to use smaller words he's from the states a country were nearly 50% of the population voted for a criminal as they thought, who better to stop corruption than a tasteless mob linked con artist.

[ken seeber]

Sorry boys and girls, you've all been wasting your time.....:clap:

https://www.astronaerospace.com/

[Flettner]

A lot of mouths to feed, send us money now.

[husaberg]

Mr cool is the vice president.
i was looking up the bladon bros the other day there were the go to people for Aemacchi racing engine parts
they are dong mini turbines as range extenders

Bladon Jets

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

https://www.bladonmt.com/

[lohring]

Below is a really clean two stroke. (may be actually a four stroke)

LOL

Lohring Miller

https://external-preview.redd.it/Tk74Q_scttL1KTT-o8LtA_c6hhPY35dBT3skeIgW72U.jpg?auto=webp&281c22f6

[Vannik]

https://www.carthrottle.com/post/mazda-has-patented-a-supercharged-two-stroke-engine-for-some-reason/

[husaberg]

https://www.carthrottle.com/post/mazda-has-patented-a-supercharged-two-stroke-engine-for-some-reason/

Neels they seem to have added valves to it...

[ceci]

I'm excited that KTM has decided to drop the use of the carb on most 2-Strokes.

For 2023 only the small 2-Stroke models "85SX, 65SX and 50SX" will use a carburetor.

When the small 2-Stroke engines stop using the carburetor, it will be the revival of the 2-Stroke, since its use will be implemented beyond off-road (many countries have laws "power limits to 11KW or 15CV" that would benefit the small 2-Stroke).

The question is: KTM will be interested in negotiating with whoever may have the solution or, on the contrary, will wait to obtain it as it obtained the TPI.

[Haufen]

Seems like the Yamaha-Minarelli engine from the top of the page has achieved Euro-5 homologation in the meantime.

https://www.motorcyclesports.net/articles/motori-minarelli-has-a-new-two-stroke-engine-that-is-euro-5-compliant

from the article:


The bikes are set to hit the European market in the summer of 2023, however, while their main focus will be for the trails and off-road courses, there’s a chance that you could ride this bike from your home all the way to the trails. That’s right, the new 300cc two-stroke engine in the upcoming Fantic XE has managed to acquire Euro 5 homologation.


352005

[Haufen]

It is assumed, that this engine fires every engine revolution

https://www.deltahawk.com/engines/#technology

353186

[husaberg]

It is assumed, that this engine fires every engine revolution

https://www.deltahawk.com/engines/#technology

353186

it was brought up in another thread a few years back someone on kb knows someone involved...

https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1131199545&highlight=deltahawk#post1131199545


https://deltahawk.com/

One of the lead designers is on this forum :drool:

[Vannik]

It is assumed, that this engine fires every engine revolution

https://www.deltahawk.com/engines/#technology

353186

It was for the designer of this engine that I added the sequential turbo / super option in EngMod2T.

[husaberg]

It was for the designer of this engine that I added the sequential turbo / super option in EngMod2T.

You're not giving much away......

[Vannik]

You're not giving much away......

He is a member here, he can reveal more if he chooses, not my place to do so.

[husaberg]

He is a member here, he can reveal more if he chooses, not my place to do so.

Can you remember what either Mike Costin or Ken Duckworth proposed as the silly end of turbo charging rules it was some like using a engine for a air pump to start a jet turbine or similar i was trying to find iwhat he said but it seemed very similar to a rocket antilag.

[Vannik]

Can you remember what either Mike Costin or Ken Duckworth proposed as the silly end of turbo charging rules it was some like using a engine for a air pump to start a jet turbine or similar i was trying to find iwhat he said but it seemed very similar to a rocket antilag.

Sorry no I do not.

[Niels Abildgaard]

Some austrians get paid to devellop a twin two stroke range extender for electric cars.

https://www.fvt.at/ka/en/references/layout-and-design-of-an-innovative-range-extender-engine.html

The Text states that only blower longitudinal scavenging will allow charge control good enough for three way catalyst.
For a multicylinder it is simpler to slush a lot of oil around in crankcase,but I dream single cylinder/inverted V2 ,sidevalved,crankcase scavenged,catalyst equiped ligth aircraft engines.
If someone know where Ken Seeber of Orbital can be contacted he can maybe explain if and why the austrians claim is true?

https://cdn2.imagearchive.com/homebuiltairplanes/internal_data/attachments/139/139763-71243652ef1330cb51f0894f1caf3771.data?response-expires=Sun%2C%2002%20Jul%202023%2004%3A03%3A29%20 GMT&response-content-type=image%2Fjpeg&X-Amz-Content-Sha256=UNSIGNED-PAYLOAD&X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=I3UPHPWOPY63ZMOGLZFM%2F20230625%2Fnyc3% 2Fs3%2Faws4_request&X-Amz-Date=20230625T040330Z&X-Amz-SignedHeaders=host&X-Amz-Expires=604799&X-Amz-Signature=335082e73546ebebc0cd3a2a6819f597c002694a cc23991bd10dfdbd84a2c003

Picture show that the volume of installation or mass is not the same for crancase and blower feed.

[ken seeber]

Neils, this is me Ken Seeber, more commonly known as Kensational.

It is over 22 years since I last worked at Orbital. As you are probably aware, the key feature of the technology is the use of a 2 fluid fuel injection system. A small compressor, around 1/20 th of the engine displacement is used to both propel and atomise the metered fuel into the cylinder. This atomisation is also adequate to allow the engine to run on heavy fuels such as Jet Fuel A, pretty much the same as kerosene. From what I understand, this is a logistical requirement, allowing the military to use the same fuel in all mobility applications, eg jeeps, tanks, planes boats, personnel carriers etc.

In Orbital’s case for UAV applications, the engine is of 50cc but I think they might also do more powerful and multi cylinder versions, but only guessing here. Being a developed DI system, this would offer a light weight powerplant with a relatively good fuel consumption. And possibly better emissions, but that would not be a factor with today’s wartime troubles.

https://orbitaluav.com/

Had a look at the details of the range extender engine. Not too sure on your level of interest in this. For me however, it looks complex, heavy, expensive and undeveloped. If I was looking at a range extender system, it’d be hard to go beyond something like a Chinese copy of something like a 6 hp Honda GX200. In Awestralia, one can buy one of these (commonly referred to a Chonda) retail for <$200 retail. Hard for me to say, given my passion for 2 strokes, in my case, ported and crankcase, or DCI inducted.

[Vannik]

The Text states that only blower longitudinal scavenging will allow charge control good enough for three way catalyst.

Niels, is longitudinal scavenging just a "bad" translation of Uniflow scavenging?

[Niels Abildgaard]

Niels, is longitudinal scavenging just a "bad" translation of Uniflow scavenging?

Yes off course.
Old age and all that.
Should it be named skewed uniflow sidevalved scavenging or skewscavalved ?

https://drive.google.com/drive/folders/1UqF2OBh8ta5A-
z0euWpIC_t4wKCekzZP (https://drive.google.com/drive/folders/1UqF2OBh8ta5A-z0euWpIC_t4wKCekzZP)

For normal Uniflow see session 2.1

[Niels Abildgaard]

Neils, this is me Ken Seeber, more commonly known as Kensational.




Had a look at the details of the range extender engine. Not too sure on your level of interest in this. For me however, it looks complex, heavy, expensive and undeveloped. If I was looking at a range extender system, it’d be hard to go beyond something like a Chinese copy of something like a 6 hp Honda GX200. In Awestralia, one can buy one of these (commonly referred to a Chonda) retail for <$200 retail. Hard for me to say, given my passion for 2 strokes, in my case, ported and crankcase, or DCI inducted.

Hello Ken and thank You for answering.
My interest is the claim that it can be equipped with a three way catalyst.
I have not much knowledge but I think that the ZrO sensor tries to maintain Lambda =1 no unused Oxygen in engine exhaust.
A normal two stroke with direct charge loss will mess it up.
Orbitals system with blowair,stratificatio and what not also.
The austrians put ca half the possible charge in cylinder,skew the exhaust timing and do not loose anything.
But I do not see that either crancase- or blower scavenge make a difference.
And crankcase scawenging makes engine lower mass and engine heigth


https://cdn2.imagearchive.com/homebuiltairplanes/internal_data/attachments/139/139763-71243652ef1330cb51f0894f1caf3771.data?response-expires=Sun%2C%2002%20Jul%202023%2004%3A03%3A29%20 GMT&response-content-type=image%2Fjpeg&X-Amz-Content-Sha256=UNSIGNED-PAYLOAD&X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=I3UPHPWOPY63ZMOGLZFM%2F20230625%2Fnyc3% 2Fs3%2Faws4_request&X-Amz-Date=20230625T040330Z&X-Amz-SignedHeaders=host&X-Amz-Expires=604799&X-Amz-Signature=335082e73546ebebc0cd3a2a6819f597c002694a cc23991bd10dfdbd84a2c003


If you load a two stroke cylinder half and a fourstroke full You have same power but maximum pressure in the two stroke is only half.
Half mass I would say

[Pursang]

Yes off course.
Old age and all that.
Should it be named skewed uniflow sidevalved scavenging or skewscavalved ?


Perhaps it should be called Detroit Diesel 2.1

[Niels Abildgaard]

Perhaps it should be called Detroit Diesel 2.1

Will a sidevalved diesel be possible and usefull?
Compression ratio?
Blow down time area?
Some of my students still devellop usefull uniflow diesels at Burmeister &Wain in Copenhagen.
They made uniflowed one valve per cylinder ships engines before Detroit I think.

[Pursang]

Perhaps I should have called it Detroit Petrol 1.0
The engine shown is spark ignited.
https://www.fvt.at/assets/files/ka/Referenzen/MPTREX/MPTREX.png

Sidevalve is a very simple and compact layout.
Valve lift can be earlier or later plus faster and higher than OHV, without any piston interference.
Looks like they are using 2 valves per cylinder for sufficient blow-down TA

Compression can be quite high with a flat head and flat top piston.
Limitation is transfer area from top of cylinder to the valves. (Much bigger issue for sidevalve inlets than for exhausts)
They are using 50% of (the possible) input charge for lower peak pressure and I assume a more 'scrubbable' exhaust.

Interesting idea, wonder if it will go anywhere!

[Pursang]

Here is an old idea, re-presented in a new(ish) way with some modern materials and engineering.

The review and commentary is pretty honest & thorough.


https://www.youtube.com/watch?v=9I0_3qFmPUM

[Niels Abildgaard]

[QUOTE=Pursang;1131217482]Here is an old idea, re-presented in a new(ish) way with some modern materials and engineering.

The review and commentary is pretty honest & thorough.




The usual bugbear is the high friction due to very high speed between piston roller and camc.
I do not see how they manage to avoid piston and roller to skew and make a mess?

[Pursang]

[QUOTE=Pursang;1131217482]

The usual bugbear is the high friction due to very high speed between piston roller and camc.
I do not see how they manage to avoid piston and roller to skew and make a mess?

They are using 2 widely spaced rollers per piston, reducing skew, but adding friction.
They will argue that elimination of the gudgeon and big end bearings will balance the friction equation.
However, the long extended skirts pump it up again.

My question #1 is: What stops the pistons from sitting 'stuck' up in the bores (ie. not contacting the swish plates or just bouncing against the high point) when the fuel and ignition are switched off and the engine shuts down?

Q.#2 is how do you start it again, if this is occurring?

[Pursang]

Interesting investigation and experiment: Maximising Torque output using linear actuation rather than a rotary crank mechanism.

Problem of "stall" solved with bearings on both sides of the swish plate.


https://www.youtube.com/watch?v=xev18rBrNr0

[Vannik]

DeltaHawk Engines has received FAA Type Certification for its highly innovative, jet-fueled aircraft piston engine.

https://www.deltahawk.com/2023/05/18/faa-certification/

[Pursang]

DeltaHawk Engines has received FAA Type Certification for its highly innovative, jet-fueled aircraft piston engine.


This is certainly a big advance in aero engines compared to the Continentals & Lycomings and their 1940's tech.
Piston ported 2S, liquid cooled, compression ignition, mechanical injection, jet fuel (not avgas).

Well done to have gotten FAA approval, looks like this actually has a future.

[ceci]

https://drive.google.com/drive/folders/1UqF2OBh8ta5A-
z0euWpIC_t4wKCekzZP (https://drive.google.com/drive/folders/1UqF2OBh8ta5A-z0euWpIC_t4wKCekzZP)



Thank you for providing the link to the DI2S files,

[Pursang]

Thank you for providing the link to the DI2S files,

Can't view the files directly on-line... but can download. Thanks!

[ceci]

Can't view the files directly on-line... but can download. Thanks!

I was looking at the page of the Polytechnic University of Valencia "UPV" (also on the page of the CMT "center of thermal engines) on the page of the French petrol institute "IPF" I did not find anything

It is stimulating to have knowledge of those who are investigating

[Pursang]

Interesting presentation by Stihl on use of E-fuels in IC small engines. (DI2S - Session 1.4)

A battery leaf blower produces more CO2 emissions PRIOR to use, than the IC/E-fuel version throughout it's entire use/lifecycle.:shit:

353539

E-Fuels are the non-fossil fuels: Alcohols, Bi-diesels, synthetic gasoline, etc.

[Vannik]

If you are on LinkedInn:

https://www.linkedin.com/groups/4395138/

[SwePatrick]

A high performance injected project running on e85 and castorbased oil:

Teaserclip of build series:
Just released part II yesterday.


https://www.youtube.com/watch?v=JDoAUQmc094&t=23s

[ken seeber]

FREE to good (or bad) home.

In the process of tidying up, I have this Piaggio 50 cc DI cylinder head. It features a compressor which drew in carb'd or EFI'd fuel mix.

Lots of info, here's just one for example: https://modernvespa.com/forum/topic87835

Message me if interested. You pay freight of course.

Hate to see it scrapped.


354150354149354151

[ceci]

FREE to good (or bad) home.

In the process of tidying up, I have this Piaggio 50 cc DI cylinder head. It features a compressor which drew in carb'd or EFI'd fuel mix.

Lots of info, here's just one for example: https://modernvespa.com/forum/topic87835

Message me if interested. You pay freight of course.

Hate to see it scrapped.


354150354149354151

It's like a mechanical DITECH.
And how does it get from Italy to Orvital in Australia?

[ken seeber]

It's like a mechanical DITECH.
And how does it get from Italy to Orvital in Australia?

Ceci, I think it came to Orbital when we were doing the DiTech application work for Piaggio. The guy who came up with this was Dr Marco Nuti of Piaggio. In this case the compressor was fuelled with an EFI injector.

I personally loved the concept and in fact made up a unit, using an inverted OS model plane engine, 1:1 chain driven from the crank, using a simple spray bar carb. On reflection, this was 20+ years ago.

As usual, I didn't have a dyno to prove it on, but it certainly could be made to idle very smoothly.

Just don't know why Fletto hasn't tried this: he just loves an engine with a small crank and piston on top of the main cylinder.:niceone::niceone:

354193354194354195354196

[diesel pig]

Ceci, I think it came to Orbital when we were doing the DiTech application work for Piaggio. The guy who came up with this was Dr Marco Nuti of Piaggio. In this case the compressor was fuelled with an EFI injector.

I personally loved the concept and in fact made up a unit, using an inverted OS model plane engine, 1:1 chain driven from the crank, using a simple spray bar carb. On reflection, this was 20+ years ago.

As usual, I didn't have a dyno to prove it on, but it certainly could be made to idle very smoothly.

Just don't know why Fletto hasn't tried this: he just loves an engine with a small crank and piston on top of the main cylinder.:niceone::niceone:

354193354194354195354196

I love it, I was told a number of times when I was a young fella a IC engine was just a fuel/air pump and here you are using that model plane engine as a pump!

[Flettner]

This will be going on the AG soon

[ceci]

Ceci, I think it came to Orbital when we were doing the DiTech application work for Piaggio. The guy who came up with this was Dr Marco Nuti of Piaggio. In this case the compressor was fuelled with an EFI injector.

I personally loved the concept and in fact made up a unit, using an inverted OS model plane engine, 1:1 chain driven from the crank, using a simple spray bar carb. On reflection, this was 20+ years ago.

354193354194354195354196

Thank you very much for clarifying my doubt, Dr. Marco Nuti from Piaggio you have good publications in which you discover Piaggio's attempts to obtain a clean 2S engine (a vespa 200 with mechanical injection, another with the IAPAC system "by Pierre Duret") .
And the derbi TSI system also uses a compressor (in this case parallel to the cylinder) you have something

[katinas]

Methanol fueled two stroke ship engines testing.

https://www.man-es.com/discover/methanol-fueled-ships

[SwePatrick]

Just putting this here as a teaser of upcoming video, keep an eye out =)


https://youtube.com/shorts/NwVbYRizxWg?si=__UzVHtFz7utnIC4

[Niels Abildgaard]

Velosolexes were good for 500 liter of fuel so not much money saved by using 35% less,but much cleaner exhaust
https://imgur.com/a/6xj5esC
https://imgur.com/a/6xj5esC

There was a picture of an austrian proposal for a clean,lean,wet sump,sidevalved two-stroke twin on the web once.
https://proxy.imagearchive.com/934/934dc3274a1a3d7f0d42d64ebae1156a.png