Oddball engines and prototypes

[tjbw]

I was told Wankel engines were more suited to higher speed constant rpm operations,
how true is that opinion?

The competition success achieved by, Mazda, and Norton, doesn't support that view.

[eldog]

The competition success achieved by, Mazda, and Norton, doesn't support that view.

I know about the success, was just curious as a lecturer I had, a while back, mentioned about high speed running - maybe I wasn't listening properly at the time.
My memory isn't what it used to be. thanks for the info.

[husaberg]

I know about the success, was just curious as a lecturer I had mentioned about high speed running - maybe I wasn't listening properly at the time.
My memory isn't what it used to be. thanks for the info.

Maybe what he meant was they are better at constant sustained high rpm than the competition is.
Their balance is superior which help as does their lack of poppet valves.

or maybe he was refering to the competition carbon apex seals used until mazda devloped the ceramic seals..
these initial carbon apex seals were only effective at high rpm.

[WilDun]

Maybe what he meant was they are better at constant sustained high rpm than the competition is

A few years ago Norton were developing another Wankel suitable for aircraft, no doubt because of the smoothness and good power to weight ratio. In aircraft, constant speed running is the norm, however fuel consumption in aircraft is paramount and it looks like it may have fallen down there - can't see any other reason. Knowing that they had done a lot of development work with the Norton racers they should have had that sussed.
So why would they have tried it in that role without drastically improving fuel economy first, knowing that fuel consumption was so important?

I hope that if they (Wankel engines in general) can get the fuel consumption thing sorted and get HCCI working with it, that the Wankel will be back in business!
I'm not so sure that the Norton company (in the aero engine and industrial field) had much connection with the bikes - but I don't really know the story there though.

BTW I did notice that the racers did smoke quite a lot.

[Pursang]

I have a 'vintage-ish' cast iron 2-stroke cylinder, 64mm bore x 54 stroke, that is being developed to do something it was never intended to do.

The inlet and exhaust ports and ducts can be effectively enlarged by cutting, machining, s/s welding, brazing, etc.

The big problem is that it is severely transfer challenged. They are small, recessed into the cylinder wall, and fed only from windows in the piston skirt.

There is room in the wall for 12-15mm wide ports on either side of the existing one and heaps of empty space over the inlet.

So, the Oddball question, has anyone seen, heard of, or actually added, extra transfers to an engine, through EXTERNAL ducts? Google couldn't help much.

Nowhere at the cylinder to case junction to take them off, i will probably need to cut into the back wall of the main or tap them directly into the crankcase.

cheers, Daryl.

[Grumph]

Yes - early Kart engines were frequently modified like that. The McCulloch engines with barrel in unit with the case lent itself to welding in additional tubular transfers.
Personally, I've seen additional internal passages added. A Villiers Starmaker I rebuilt had been altered in Melbourne to have an additional pair of transfers via trenches in the bore - TD1C style. Made a significant improvement too.

[Pursang]

Thanks Grumph,

So not unheard of, and not without merit.

Engines in this family powered a lot of early Karts.

cheers, Daryl.

[Grumph]

Thanks Grumph,

So not unheard of, and not without merit.

Engines in this family powered a lot of early Karts.

cheers, Daryl.

Iron Horse ?

At least those dimensions give you a lot of modern alternative replacement parts.....

[husaberg]

A few years ago Norton were developing another Wankel suitable for aircraft, no doubt because of the smoothness and good power to weight ratio. In aircraft, constant speed running is the norm, however fuel consumption in aircraft is paramount and it looks like it may have fallen down there - can't see any other reason. Knowing that they had done a lot of development work with the Norton racers they should have had that sussed.
So why would they have tried it in that role without drastically improving fuel economy first, knowing that fuel consumption was so important?

I hope that if they (Wankel engines in general) can get the fuel consumption thing sorted and get HCCI working with it, that the Wankel will be back in business!
I'm not so sure that the Norton company (in the aero engine and industrial field) had much connection with the bikes - but I don't really know the story there though.

BTW I did notice that the racers did smoke quite a lot.

Pretty sure the Norton wankel aircraft project was for a pilotless target drone for missle testing the yanks used to modify mazada engines for the same thing. (racing beat i think)
So high fuel use wasn't really mission critical
Vincent engines were used for a similar thing (the picador)

The later Renesis as used in the RX8 partially solved the excessive fuel use by variable port timing and moving the EX ports to the side plates thus reducing overlap.
they also produced similar power to the earlier turbo models

https://www.youtube.com/watch?v=2g_mrbXYiCo

[pete376403]

A few years ago Norton ...racers did smoke quite a lot.

IIRC the race motors used air cooling for the interior of the rotor. The air was pulled through using exhaust- similar to crankcase evacuation systems. The cooling worked but picked up oil which ended up as a smokey exhaust. One of the reasons the race motor could never have become a road motor.

[husaberg]

IIRC the race motors used air cooling for the interior of the rotor. The air was pulled through using exhaust- similar to crankcase evacuation systems. The cooling worked but picked up oil which ended up as a smokey exhaust. One of the reasons the race motor could never have become a road motor.

pretty sure they also used an oil feed total loss, only a small ammount though come to think of it i am pretty sure as the Suzuki RE5 was too. Highly likely the mazda was as well.
The britten used to smoke when cold, as did Dave Morris's BMW single.
the exhaust air vac pac, i think was later deleted when the cooling was improved on later models.
the race motor was develed directly from the road interpol which was very reliable.
I think all norton rotary's had the housings plated and machined by Mazda
the road bikes initally had the old triumph gearbox and i think later had a old Yamaha xj600 or similar gearbox.

[Pursang]

Iron Horse ?

At least those dimensions give you a lot of modern alternative replacement parts.....

It's a 'Victa' This cylinder is a 160 with 61.5mm bore std.

There is a Suzuki TS185 piston, at 64mm which gives 173.7 cc, perfect for the class.
If 64 is too big, the PE175 is available at 62mm.

Bottom ends are actually pretty solid. Unconfirmed reports of 16,000rpm in karts, way back when.
I won't be looking for any thing like that, 9,500 + some over-rev should be plenty.

cheers, Daryl.

[Frits Overmars]

I have a 'vintage-ish' cast iron 2-stroke cylinder, 64mm bore x 54 stroke... The big problem is that it is severely transfer challenged...
9,500 + some over-rev should be plenty.Plenty indeed Daryl. Good cylinder filling at 9500 rpm would require a transfer angle.area of about 114000°mm². In other words: with a sensible 130° transfer timing you'd need over 100 mm total transfer port width. That will take some doing. And then you'll have swapped one problem for an other: how to cool that lump of cast-iron.
I wouldn't go there...

[Pursang]

Thanks for the input Frits. 130 degree of transfer was exactly my plan (& say 190 Ext & 166 inlet)

100mm of width should be doable. Efficient ducts to feed them will be the tricky part.

If I keep it piston ported, is there any reason I can't put a transfer port or two above the inlet port?

As I don't have direct access to the crankcase, except by tapping into the main transfer,
I am thinking of creating transfer 'holding chambers' outside the cylinder and feeding the extra ports from there.

Creating reasonable directions will be based on some good stuff I read somewhere about Pizza slices, or something.
Actually optimising and balancing the flow without a squillian hours of Sim & Dyno, is unlikely to occur.
I'll just try to make it look a bit like something that is known to work rather well.

Cooling the lump shouldn't be my biggest problem, Lots of airflow available.
I can even add water vapour to the air, if required and using Methanol fuel is another option.

20HP at the rear wheel will be ideal, with enough torque to steadily climb back from 38 & 27% rev drops in the lower gears.
I am also considering a CVT or go kart clutch between the engine & gearbox to help cope with this, despite the power cost.

I'm putting some pictures together, to post soon.

cheers, Daryl. PS Not many would go there, in fact None have....that why I'll do it!

[Pursang]

.
And...just to prove that an old mower engine is not a hijack of the rotary discussion.....

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331544

331545

Discussion & more pics here: https://www.outdoorking.com/forum/ubbthreads.php?ubb=showflat&Number=42597

Cheers, Daryl.

[Frits Overmars]

If I keep it piston ported, is there any reason I can't put a transfer port or two above the inlet port?No theoretical objection. You'll just have to find the space for it.


Creating reasonable directions will be based on some good stuff I read somewhere about Pizza slices, or something.:killingme


Cooling the lump shouldn't be my biggest problem, Lots of airflow available.Airflow won't be the problem; heat flow from the cylinder bore to the outer ends of the cooling fins will be, and there is not a great deal you can do about that.
Cast-iron will be cast-iron, you know.


20HP at the rear wheel will be idealNow we are running into conflicting desires. With maximum power at 9500 rpm, you not only need over 100 mm of total transfer port width, you'll also need a corresponding amount of blowdown angle.area. With 190° exhaust timing that just isn't achievable. We're dealing with a short-stroke engine here, remember?
You'll need a main exhaust port 194° high and 45 mm wide and two auxiliary ports, each 192° high and 20 mm wide. And I bet there isn't enough cast-iron around
and the cylinder studs would be in the way. But if you manage to realize the above, and if you don't totally mess things up, you'll have more than 30 hp at the wheel.
If you're serious about the 20 hp, why don't you drop the 9500 rpm to maybe 7000 rpm? Then you can use milder port timings and get a more forgiving engine character.

[Grumph]

Airflow won't be the problem; heat flow from the cylinder bore to the outer ends of the cooling fins will be, and there is not a great deal you can do about that.
Cast-iron will be cast-iron, you know.
If you're serious about the 20 hp, why don't you drop the 9500 rpm to maybe 7000 rpm? Then you can use milder port timings and get a more forgiving engine character.

This approach works - my 197 Villiers is tuned for peak power at 8000 - but is very torquey from around 6000. Light bike pulling a high gear.
Probably makes a little more than 20HP (optimistic brag...)
The drawback to this is chamber length. the one on the Villiers goes down the left then has a short section across in front of the rear tyre before going up the right side.
Heat flow in the fins at least has only a short trip to the tips (cough)....I'm going to give the bike one more go but on alky this time before possibly doing a watercooled conversion.

[WilDun]

.
And...just to prove that an old mower engine is not a hijack of the rotary discussion.....
Cheers, Daryl.

Is it cast iron? if it's cast iron its good - cast iron is the best material :yes: - ie for playing around with anyway.

[WilDun]

Going back to HCCI, (and I know it's a silly question) - how well would the side valve engine work with HCCI? - (or with the use of hydrogen fuel!),seeing that combustion chamber shape is not so important as it was.
Of course there is the uneven heating to consider (but that doesn't appear to be a problem in a modern two stroke).
Just a thought - a SV engine looks quite compact and tidy compared to a modern four stroke, with a head as big as the rest of it!

DARYL, this thread was made for hijackers, that "other" thread is tough going for hijackers!

[eldog]

Maybe what he meant was they are better at constant sustained high rpm than the competition is.
Their balance is superior which help as does their lack of poppet valves.

or maybe he was refering to the competition carbon apex seals used until mazda devloped the ceramic seals..
these initial carbon apex seals were only effective at high rpm.

I guess I will never know.

most likely from balance, he lectured us in thermodynamics mostly air con related stuff, but occasionally got ahead of himself and diverted when asked random questions from the inmates:nya:

he also researched engines and combustion etc, followed hydrogen and electric development.

cool dude, knew his stuff.

[husaberg]

Thanks for the input Frits. 130 degree of transfer was exactly my plan (& say 190 Ext & 166 inlet)

100mm of width should be doable. Efficient ducts to feed them will be the tricky part.

If I keep it piston ported, is there any reason I can't put a transfer port or two above the inlet port?

As I don't have direct access to the crankcase, except by tapping into the main transfer,
I am thinking of creating transfer 'holding chambers' outside the cylinder and feeding the extra ports from there.

Creating reasonable directions will be based on some good stuff I read somewhere about Pizza slices, or something.
Actually optimising and balancing the flow without a squillian hours of Sim & Dyno, is unlikely to occur.
I'll just try to make it look a bit like something that is known to work rather well.

Cooling the lump shouldn't be my biggest problem, Lots of airflow available.
I can even add water vapour to the air, if required and using Methanol fuel is another option.

20HP at the rear wheel will be ideal, with enough torque to steadily climb back from 38 & 27% rev drops in the lower gears.
I am also considering a CVT or go kart clutch between the engine & gearbox to help cope with this, despite the power cost.

I'm putting some pictures together, to post soon.

cheers, Daryl. PS Not many would go there, in fact None have....that why I'll do it!

http://www.vintagekart.4t.com/catalog_3.html

[Flettner]

.
And...just to prove that an old mower engine is not a hijack of the rotary discussion.....

331543

331544

331545

Discussion & more pics here: https://www.outdoorking.com/forum/ubbthreads.php?ubb=showflat&Number=42597

Cheers, Daryl.

I had one of those. Had the hacksaw resting on it ready to modify it into a super charger for my Honda 100 bucket racer, back in the day. I couldn't bring myself to cut it up as I figured they were quite rare, so ended up giving it to an engine collector. Ended up cutting up a roots supercharger and thinning it down to 25mm to get the required pumping volume. I'd seen plenty of these about.

[Pursang]

Now we are running into conflicting desires. With maximum power at 9500 rpm, you not only need over 200 mm of total transfer port width, you'll also need a corresponding amount of blowdown angle.area. With 190° exhaust timing that just isn't achievable. We're dealing with a short-stroke engine here, remember?
You'll need a main exhaust port 194° high and 45 mm wide and two auxiliary ports, each 192° high and 20 mm wide. And I bet there isn't enough cast-iron around and the cylinder studs would be in the way.
But if you manage to realize the above, and if you don't totally mess things up, you'll have more than 30 hp at the wheel.
If you're serious about the 20 hp, why don't you drop the 9500 rpm to maybe 7000 rpm? Then you can use milder port timings and get a more forgiving engine character.

Rats, I had up to 120mm,...NO way to get 200. That's OK, I'm still at the Drawing (circuit) Board.
Here is the space I have to work with, (with some wishful thinking).

45 years with a hot-rodded Bultaco (195/135/172) I've forgotten what forgiving means. (I do know what 'loaded-up" means).

Cylinder studs should/would/could be a problem, but I can revert to the original setup with short studs into the case to hold the cylinder down. This gives access & room for the A & C transfers and the exhaust auxiliaries.
Bolt the head down through the top 3. External structural bracing if required.

331555


This approach works - my 197 Villiers is tuned for peak power at 8000 - but is very torquey from around 6000. Light bike pulling a high gear.
Probably makes a little more than 20HP (optimistic brag...)
The drawback to this is chamber length. the one on the Villiers goes down the left then has a short section across in front of the rear tyre before going up the right side.
Heat flow in the fins at least has only a short trip to the tips (cough)....I'm going to give the bike one more go but on alky this time before possibly doing a watercooled conversion.

Pipe length won't be an issue for me, in this application.
I had a friend with a Villiers 197 in a HJH Scrambler, hard to fit a long & fat(ish) pipe with 50's period Style.
Megaphones were more the fashion, back then.


Is it cast iron? if it's cast iron its good - cast iron is the best material :yes: - ie for playing around with anyway.

Aaaargh Iron! Dimensionaly pretty stable, 'til it melts?
Almost self lubricating. No thermal barrier at a material change line.
Boring & honing & clearancing to Any size, At home, At will, eh Wil?
Adding and removing bits, repair a score with a piston ring and a Dillon torch! Lots to love.:love:

So here is a 'Phantom', paint shopped, pic of the relevant model 160 engine.
Much nicer ones in the link by Husaberg.

331556

The bump for the main (only) transfer is clearly visible. I'd rather not modify the alloy case.
As I see it I could:

a) Bore into the bump, enlarge access and create a chamber to feed 3 pipe ducts to the A, C & D ports.

b) Similar to a) but remove (mill out) fin #6, cut the new ports and weld in a cover plate between fins #5 & #7.
Sort of a circumferential transfer set up.

c) Go the reed option, create a chamber behind the reed block and feed the ports from there.

d) Fit a blower to overcome any flow & distribution issues. Probably need to discuss sizing options with Flettner.

Undoubtedly, the best option is one I haven't considered, yet.

Sincere thanks, for the advice and comments so far.

Cheers, Daryl.

[Frits Overmars]

Rats, I had up to 120mm... NO way to get 200.No worries Daryl, those 200mm were a typo. It should have read 100 mm. I have corrected the concerned post.

[ken seeber]

Daryl,
Here’s a pic of what someone over your way is doing. Obviously, with the bolt on transfer passages, it is based on a 125 & is still a 125, but I think the 160 had cast-in “open trench” transfer passages, so this may be more difficult than just bolting on.

331557

[Pursang]

Yes Ken, the 160 has the cast trench transfer ducts.

The plastic hose on the 125 transfer cover has got me thinking.:scratch:
I guess its the impulse line for the pumper carby......but if I found some larger tube, that could handle the heat of a red-hot iron barrel, I could make nice smooth extra ducts without the hassle of putting compound curves in S/S or Copper or any other metal. :woohoo:

Cheers, Daryl.

[Pursang]

:innocent:

331558

Lasts a fair while in the frying pan. Min bend radius for 16mm is 165mm, could work.

found here: http://www.flexicraft.com/industrial_hose

cheers, Daryl.

[Pursang]

It helps if you know what to Google for!

19mm Silicon Hose used by Turbo enthusiasts (& young, noisy "Doof Doof" import driving, wankers).

331559

[Frits Overmars]

331558
Lasts a fair while in the frying pan. Min bend radius for 16mm is 165mm, could work. found here: http://www.flexicraft.com/industrial_hoseAprilia transfer duct inner radius is 16 mm. What's more, with insufficient blowdown (could already happen if you rev it a bit higher than intended) exhaust gases will enter the tube and the PTFE will give off very nasty fumes.

[Pursang]

Aprilia transfer duct inner radius is 16 mm. What's more, with insufficient blowdown (could already happen if you rev it a bit higher than intended) exhaust gases will enter the tube and the PTFE will give off very nasty fumes.

The ducts Will be longer than ideal, but might add some additional case volume.

Extended over-rev is unlikely once in top gear, assuming gearing is correct.

Won't be anyone behind me to breathe the fumes.

cheers Daryl

[Pursang]

with insufficient blowdown (could already happen if you rev it a bit higher than intended)

Could this be taken as another indication that, with the oversquare bore/stroke, Ex timing needs to be a bit higher than normal and the Ex auxiliaries need be as large as physically possible?

Transfer blocking at over-rev seems a better option than bearing seizing or con-rod chucking!!

As far as a rev limit, that still comes down to producing a really solid 20HP at the rear wheel.
Not just a flash peak reading, it will need to maintain it for around a minute, and cover any progressive losses, due to heat loading, etc.

The Victa has no gearbox, I will be running it through a six speed Kawasaki (KMX125) with the crank replaced with a jackshaft, so some losses there.
And the option (if necessary) of a CVT or centrifugal clutch in between , with more losses.

Up to date, any modifications and (usually) improvements to my projects have been based on empirical methods and information.
This is a new and interesting exercise.

Cheers, Daryl.

[Grumph]

Daryl, is someone over there casting sunburst heads for the Victa's ?
How can I get an unmachined one ?
Thanks

Greg

[Pursang]

Hi Greg,

No new heads that I know of. Most of the stuff online is restoration of gear from the early days of karting in the sixties.
Modified Victa's also had a burst of attention in the very early days of mini-bike racing.

The head on the square case motor looks very tough. My picture is a poorly paint-shopped Maico head.

I haven't found one to measure yet but the early TS185 V-fin head looks like it might be adaptable to the 160 engine.
331560

A fair bit of work required to create a modern squish chamber.
Don't know how well they weld either, some early Suzuki stuff is more like zinc pot metal than real Aluminium.

'Lost foam' casting looks ideal for the creation of custom, one-off, air cooled heads.

Cheers, Daryl

[Pursang]

Here's a substantial Head.

331561

And I can't find where this is from, but someone has made a nice wooden pattern for a Bultaco styled one with plenty of meat at the base of the fins.

331562

Cheers, Daryl.

[husaberg]

Daryl, is someone over there casting sunburst heads for the Victa's ?
How can I get an unmachined one ?
Thanks

Greg


RESUME MARK MANSELL
Mobile: 0406 043 953
Tel: (02) 96059562 (h)
Email:mmansell@bigpond.net.au

he did this one. plus hes on your island Daryl
331563

Its even mentioned on his resume
file:///C:/Users/Glenn_2/AppData/Local/Packages/Microsoft.MicrosoftEdge_8wekyb3d8bbwe/TempState/Downloads/14_resume_12_Mark%20Mansell.%2026-3-2011%20-%20Copy.pdf

[guyhockley]

Never seen a Victa, but it sounds quite like you're heading in the same direction as many Bantam racers in the UK.

[guyhockley]

http://www.bsabantamracing.com/
The forum has loads of stuff as well as the tuning guides and articles, but attention seems to have shifted somewhat to
https://m.facebook.com/groups/222754921144299/?ref=group_header&view=group
Googling Bantam racing will bring up some more sites.

[Pursang]

Trying to determine a suitable peak rpm to meet the 20 rwhp goal.
25 at crank should cover transmission losses.

Using BMEP = HP * 6500 / Cap(L)*rpm

25 * 6500 / 0.163*7000 = 145psi (10 bar)

That might be a bit optimistic, the best of the air cooled moto-crossers were apparently lucky to get to 120
(the RM125C was 123psi at peak torque and 120 at peak hp 21.7 @ 9500 )

I'll have a better pipe design, exhaust port and transfer directions than that & maybe the squish and ignition control, but the rest leaves a bit to be desired.
(60 litres per minute of coolant for example, but then the RM didn't have that either.)

For 25hp at 10,000 rpm the BMEP = 99.7 psi (6.87 bar) which seems more achievable. (the pressure if not the revs).

What have I not considered?
(Besides the practicality of even considering it)

cheers, Daryl

[Frits Overmars]

I'll have a better pipe design, exhaust port and transfer directions than that & maybe the squish and ignition control, but the rest leaves a bit to be desired
(60 litres per minute of coolant for example.)Does that mean that you have seen the light and are switching to watercooling Daryl? In that case the good news is that you don't need 60 litres per minute;
the rule of thumb is one litre per crankshaft-HP per minute.
The bad news is that good transfer directions alone are not enough. If you are going to feed those transfer ports through tubing, as you were threatening to do the other day, chances are that the mixture columns in those ducts will be quite long and therefore quite reluctant to start flowing. So even if there is sufficient angle.area, you won't get much gass flow through all those ports, except at low revs. But at low revs you don't need the extra ports ....

[Pursang]

Does that mean that you have seen the light and are switching to watercooling Daryl? In that case the good news is that you don't need 60 litres per minute;
the rule of thumb is one litre per crankshaft-HP per minute.
The bad news is that good transfer directions alone are not enough. If you are going to feed those transfer ports through tubing, as you were threatening to do the other day, chances are that the mixture columns in those ducts will be quite long and therefore quite reluctant to start flowing. So even if there is sufficient angle.area, you won't get much gass flow through all those ports, except at low revs. But at low revs you don't need the extra ports ....

If it's water-cooled it's no longer a vintage mower / go-kart / mini-bike engine . (I might get away with a water-cooled head)
I could use any 175 cc engine, I've got a nice KDX sitting in the shed, but there's nothing very memorable about that.

Back to Cooling, ultimately the're all air-cooled, the water is just a heat transfer medium.
But I believe I need 3300 X the amount of water to absorb the heat, so 82500 litres of air/min.
I haven't found a figure for the flow restriction of a radiator, but say 50%. and assume its heat transfer ability is 100%.
Now I need 165 m3/min. or 2.75 m3/s. In my application, I'd need a radiator around 500mm2 and another 3hp.

Another interesting option would be to duct that mass flow of air over the engine, add the 50% (25 hp) of 'wasted heat', then nozzle it out the back, and generate 40lb of thrust. Add to that, the wasted heat out through the exhaust, say another 10lb and now I've got 50lb of thrust. (222 newtons)
If the bike weighs 500lb (186kg, with me aboard Ok maybe 200) I can accelerate at 1.2 m/s and reach target velocity in around a minute.
No! actually I've still got the engine power as well, so 50hp equivalent. Target velocity in 25 secs, Terminal velocity in 39. That's the Right Stuff!

Regarding the tubing ducts, (I'm sure I was just postulating & never, ever threatening), I remember Jan wishing that the internal radii could be Much Larger than was available in the RSA cylinders. Problem solved. Plus, I'll have a cooler charge because they are insulated and not in contact with the cylinder walls. ( Try some silicon oven mitts, they're great.)

If the tubing ducts are reluctant to start flowing, once they are flowing they should also be reluctant to stop?? Couldn't that increase the pressure at the port and the initial transfer flow acceleration at Tr opening?

Might need to adjust the diameters to achieve harmony at peak rev. I could put cable-ties around the hoses and adjust them progressively.

My Brain Hurts, :weird:

cheers, Daryl.

[Flettner]

If it's water-cooled it's no longer a vintage mower / go-kart / mini-bike engine . (I might get away with a water-cooled head)
I could use any 175 cc engine, I've got a nice KDX sitting in the shed, but there's nothing very memorable about that.

Back to Cooling, ultimately the're all air-cooled, the water is just a heat transfer medium.
But I believe I need 3300 X the amount of water to absorb the heat, so 82500 litres of air/min.
I haven't found a figure for the flow restriction of a radiator, but say 50%. and assume its heat transfer ability is 100%.
Now I need 165 m3/min. or 2.75 m3/s. In my application, I'd need a radiator around 500mm2 and another 3hp.

Another interesting option would be to duct that mass flow of air over the engine, add the 50% (25 hp) of 'wasted heat', then nozzle it out the back, and generate 40lb of thrust. Add to that, the wasted heat out through the exhaust, say another 10lb and now I've got 50lb of thrust. (222 newtons)
If the bike weighs 500lb (186kg, with me aboard Ok maybe 200) I can accelerate at 1.2 m/s and reach target velocity in around a minute.
No! actually I've still got the engine power as well, so 50hp equivalent. Target velocity in 25 secs, Terminal velocity in 39. That's the Right Stuff!

Regarding the tubing ducts, (I'm sure I was just postulating & never, ever threatening), I remember Jan wishing that the internal radii could be Much Larger than was available in the RSA cylinders. Problem solved. Plus, I'll have a cooler charge because they are insulated and not in contact with the cylinder walls. ( Try some silicon oven mitts, they're great.)

If the tubing ducts are reluctant to start flowing, once they are flowing they should also be reluctant to stop?? Couldn't that increase the pressure at the port and the initial transfer flow acceleration at Tr opening?

Might need to adjust the diameters to achieve harmony at peak rev. I could put cable-ties around the hoses and adjust them progressively.

My Brain Hurts, :weird:

cheers, Daryl.

Interesting, I did consider making the bottom half of a cylinder from silicon, with cavities in behind the transfers, so oil could be pumped in so as to squeeze off the transfers area. For low speed and high speed.
Never happened though.

[Frits Overmars]

Regarding the tubing ducts, I remember Jan wishing that the internal radii could be Much Larger than was available in the RSA cylinders. Problem solved. Plus, I'll have a cooler charge because they are insulated and not in contact with the cylinder walls. ( Try some silicon oven mitts, they're great.)Jan said, as do I, that the internal radii in the transfer ducts should be as large as possible. In the RSA cylinders the available duct length was used to the max.
Lengthening the transfer ducts any further which would have nullified the effect of the larger radii.


If the tubing ducts are reluctant to start flowing, once they are flowing they should also be reluctant to stop?? Couldn't that increase the pressure at the port and the initial transfer flow acceleration at Tr opening?Yes, the transfer flow would also be reluctant to stop, but the piston would not give a damn and slam the transfer ports shut regardlessly. That would create a pressure rise in the transfer ducts, but that pressure rise would not wait around till the next transfer opening; it would spread over the crankcase volume. So no compensation for the reluctant initial mass flow into the cylinder and on top of this a higher crankcase pressure after transfer closing, which would hurt the next induction phase.

Re the silicon oven mitts: they don't come in engine sizes, but you might use this thermal insulation paint, developed for the Russian space program and liberated by my friend Martijn Stehouwer of Emot Racing (www.emot.nl). Martijn became twice European classic 50 cc champion using the stuff.
331570


I did consider making the bottom half of a cylinder from silicon, with cavities in behind the transfers, so oil could be pumped in so as to squeeze off the transfers area. For low speed and high speed. Never happened though.Remember the hinged 'comma' roofs in the transfer ducts that we discussed two years ago? That didn't happen either as you came up with your sliding cylinder solution whilst I got stuck with the problem of how to operate those commas. Now I think that rubber bladders could have been a solution. Keep thinking outside the box Neil :niceone:.

[ken seeber]

Daryl, in one of my early posts to KB (but it seems to be missing) there was some discussion on cooling, I mentioned and experience when I was at Orbital baselining an aircooled PE400 engine. Basically it got hot under steady state power testing causing the power to fall, irrespective of lots of practical forced air cooling. So then we set up a small micro irrigation spray to wet the cylinder and the power just rose. So, that gave rise to a couple of thoughts:

1. Dribble water over the engine
2. Arrange a small leak of fuel from the carb so it ran all over the cylinder (if you are carb forward)
3. Arrange a hose between your good self and allow this to discharge in front of the cylinder. Drink lots of water and have lots of diuretics before you go out.:rolleyes:

[Pursang]

Interesting, I did consider making the bottom half of a cylinder from silicon, with cavities in behind the transfers, so oil could be pumped in so as to squeeze off the transfers area. For low speed and high speed. Never happened though.

That's a really good idea, I was going to have a hard time loosening off the cable ties when I got up to speed.



Jan said, as do I, that the internal radii in the transfer ducts should be as large as possible. In the RSA cylinders the available duct length was used to the max. Lengthening the transfer ducts any further which would have nullified the effect of the larger radii.

The inner radius in my B transfer is close to infinity (y axis). Horizontally, it's half the bore!

Yes, the transfer flow would also be reluctant to stop, but the piston would not give a damn and slam the transfer ports shut regardlessly. That would create a pressure rise in the transfer ducts, but that pressure rise would not wait around till the next transfer opening; it would spread over the crankcase volume. So no compensation for the reluctant initial mass flow into the cylinder and on top of this a higher crankcase pressure after transfer closing, which would hurt the next induction phase.

Fair enough...How about a couple of chambers, mounted off each side of the cylinder at transfer height, short direct ducts to the A, C & D ports. Each chamber has a reed valve fed by a large (enough) passage from the case through holes cut into the bottom of the main B transfer duct. Piston ported to the case and the B transfer, reed valved to the rest

Re the silicon oven mitts: they don't come in engine sizes, but you might use this thermal insulation paint, developed for the Russian space program and liberated by my friend Martijn Stehouwer of Emot Racing (www.emot.nl). Martijn became twice European classic 50 cc champion using the stuff.
331570

Martijn's Site looks great, some really nice gear. Looks like he's not selling the Russian Rocket paint. Pity 'cos it would be perfect for my Ram Jet cooling & propulsion system.
The only flaw with that system is we don't get the thrust until we're already travelling pretty quickly. Needs some fans and stuff to complicate it.
Here's a link to a interesting analysis of an 'oddballish' engine. A Two stroke, compound, uniflow helicopter engine that's as light and powerful and 31% more fuel efficient than the standard turbo jet. http://dtic.mil/dtic/tr/fulltext/u2/a180007.pdf Another great idea that never got off the ground. A cynic might think that Rolls-Royce and Honeywell could probably afford more Generals & Senators than the Garrett Turbo coy.

Remember the hinged 'comma' roofs in the transfer ducts that we discussed two years ago? That didn't happen either as you came up with your sliding cylinder solution whilst I got stuck with the problem of how to operate those commas. Now I think that rubber bladders could have been a solution. Keep thinking outside the box Neil :niceone:.


Daryl, in one of my early posts to KB (but it seems to be missing) there was some discussion on cooling, I mentioned and experience when I was at Orbital baselining an aircooled PE400 engine. Basically it got hot under steady state power testing causing the power to fall, irrespective of lots of practical forced air cooling. So then we set up a small micro irrigation spray to wet the cylinder and the power just rose. So, that gave rise to a couple of thoughts:

1. Dribble water over the engine
2. Arrange a small leak of fuel from the carb so it ran all over the cylinder (if you are carb forward)
3. Arrange a hose between your good self and allow this to discharge in front of the cylinder. Drink lots of water and have lots of diuretics before you go out.:rolleyes:

I think we should keep the Piss & Dribble for discussion on how to fuel this thing.:sweatdrop

re:#2 I have a preference for Amals, so that ones a given.

Version PE400 3.1 - A mist spray into the airsteam. I proposed this early on, when Frits first raised the Temperature Dragons ugly head.

I did some basic googly research on this and the results were mixed. Most of it is HVAC related & not relatively high velocity airstreams
Enthalpy differences between dry & humid air - the humid air already has more heat energy than dry, for example.
It takes more energy to raise the temperature of moist air than dry, blah blah.
Actually I think that is the solution. Heating the moist air takes more energy. (From the engine and then the airflow carries it away).

If I really had to, I could carry say, 20 litres of water to spray at the engine. (does one litre of ambient temp water mist cooling = 3 or 4 of hot recirculated water??)
and then perhaps I could spray some on the pipe, on gear changes, to lower the frequency and fill in the acceleration gaps caused by the extra weight


cheers, Daryl.

[Pursang]

Interesting, I did consider making the bottom half of a cylinder from silicon, with cavities in behind the transfers, so oil could be pumped in so as to squeeze off the transfers area. For low speed and high speed. Never happened though.

That's a really good idea, I was going to have a hard time loosening off the cable ties when I got up to speed.



Jan said, as do I, that the internal radii in the transfer ducts should be as large as possible. In the RSA cylinders the available duct length was used to the max. Lengthening the transfer ducts any further which would have nullified the effect of the larger radii.

Yes, the transfer flow would also be reluctant to stop, but the piston would not give a damn and slam the transfer ports shut regardlessly. That would create a pressure rise in the transfer ducts, but that pressure rise would not wait around till the next transfer opening; it would spread over the crankcase volume. So no compensation for the reluctant initial mass flow into the cylinder and on top of this a higher crankcase pressure after transfer closing, which would hurt the next induction phase.

Fair enough...How about a couple of chambers, mounted off each side of the cylinder at transfer height, short direct ducts to the A, C & D ports. Each chamber has a reed valve fed by a large (enough) passage from the case through holes cut into the bottom of the main B transfer duct. Piston ported to the case and the B transfer, reed valved to the rest

Re the silicon oven mitts: they don't come in engine sizes, but you might use this thermal insulation paint, developed for the Russian space program and liberated by my friend Martijn Stehouwer of Emot Racing (www.emot.nl). Martijn became twice European classic 50 cc champion using the stuff.
331570

Martijn's Site looks great, some really nice gear. Looks like he's not selling the Russian Rocket paint. Pity 'cos it would be perfect for my Ram Jet cooling & propulsion system.
The only flaw with that system is we don't get the thrust until we're already travelling pretty quickly. Needs some fans and stuff to complicate it.
Here's a link to a interesting analysis of an 'oddballish' engine. A Two stroke, compound, uniflow helicopter engine that's as light and powerful and 31% more fuel efficient than the standard turbo jet. http://dtic.mil/dtic/tr/fulltext/u2/a180007.pdf

Remember the hinged 'comma' roofs in the transfer ducts that we discussed two years ago? That didn't happen either as you came up with your sliding cylinder solution whilst I got stuck with the problem of how to operate those commas. Now I think that rubber bladders could have been a solution. Keep thinking outside the box Neil :niceone:.


Daryl, in one of my early posts to KB (but it seems to be missing) there was some discussion on cooling, I mentioned and experience when I was at Orbital baselining an aircooled PE400 engine. Basically it got hot under steady state power testing causing the power to fall, irrespective of lots of practical forced air cooling. So then we set up a small micro irrigation spray to wet the cylinder and the power just rose. So, that gave rise to a couple of thoughts:

1. Dribble water over the engine
2. Arrange a small leak of fuel from the carb so it ran all over the cylinder (if you are carb forward)
3. Arrange a hose between your good self and allow this to discharge in front of the cylinder. Drink lots of water and have lots of diuretics before you go out.:rolleyes:

I think we should keep the Piss & Dribble for discussion on how to fuel this thing.:sweatdrop


Version PE400 3.1 - A mist spray into the airsteam. I proposed this early on, when Frits first raised the Temperature Dragons ugly head.

I did some basic googly research on this and the results were mixed. Most of it is HVAC related & not relatively high velocity airstreams
Enthalpy differences between dry & humid air - the humid air already has more heat energy than dry, for example.
It takes more energy to raise the temperature of moist air than dry, blah blah.
Actually I think that is the solution. Heating the moist air takes more energy. (From the engine and then the airflow carries it away).

If I really had to, I could carry say, 20 litres of water to spray at the engine. (does one litre of ambient temp water mist cooling = 3 or 4 of hot recirculated water??)
and then perhaps I could spray some on the pipe, on gear changes, to lower the frequency and fill in the acceleration gaps caused by the extra weight



cheers, Daryl.

[Pursang]

Interesting, I did consider making the bottom half of a cylinder from silicon, with cavities in behind the transfers, so oil could be pumped in so as to squeeze off the transfers area. For low speed and high speed. Never happened though.

That's a really good idea, I was going to have a hard time loosening off the cable ties when I got up to speed.



Jan said, as do I, that the internal radii in the transfer ducts should be as large as possible. In the RSA cylinders the available duct length was used to the max. Lengthening the transfer ducts any further which would have nullified the effect of the larger radii.

Yes, the transfer flow would also be reluctant to stop, but the piston would not give a damn and slam the transfer ports shut regardlessly. That would create a pressure rise in the transfer ducts, but that pressure rise would not wait around till the next transfer opening; it would spread over the crankcase volume. So no compensation for the reluctant initial mass flow into the cylinder and on top of this a higher crankcase pressure after transfer closing, which would hurt the next induction phase.

Fair enough...How about a couple of chambers, mounted off each side of the cylinder at transfer height, short direct ducts to the A, C & D ports. Each chamber has a reed valve fed by a large (enough) passage from the case through holes cut into the bottom of the main B transfer duct. Piston ported to the case and the B transfer, reed valved to the rest

Re the silicon oven mitts: they don't come in engine sizes, but you might use this thermal insulation paint, developed for the Russian space program and liberated by my friend Martijn Stehouwer of Emot Racing (www.emot.nl). Martijn became twice European classic 50 cc champion using the stuff.
331570

Martijn's Site looks great, some really nice gear. Looks like he's not selling the Russian Rocket paint. Pity 'cos it would be perfect for my Ram Jet cooling & propulsion system.
The only flaw with that system is we don't get the thrust until we're already travelling pretty quickly. Needs some fans and stuff to complicate it.
Here's a link to a interesting analysis of an 'oddballish' engine. A Two stroke, compound, uniflow helicopter engine that's as light and powerful and 31% more fuel efficient than the standard turbo jet. http://dtic.mil/dtic/tr/fulltext/u2/a180007.pdf Another great idea that didn't get of the ground. A cynic might think that Rolls Royce & Honeywell could afford more Generals & Senators than the Garrett Turbo Co.

Remember the hinged 'comma' roofs in the transfer ducts that we discussed two years ago? That didn't happen either as you came up with your sliding cylinder solution whilst I got stuck with the problem of how to operate those commas. Now I think that rubber bladders could have been a solution. Keep thinking outside the box Neil :niceone:.


Daryl, in one of my early posts to KB (but it seems to be missing) there was some discussion on cooling, I mentioned and experience when I was at Orbital baselining an aircooled PE400 engine. Basically it got hot under steady state power testing causing the power to fall, irrespective of lots of practical forced air cooling. So then we set up a small micro irrigation spray to wet the cylinder and the power just rose. So, that gave rise to a couple of thoughts:

1. Dribble water over the engine
2. Arrange a small leak of fuel from the carb so it ran all over the cylinder (if you are carb forward)
3. Arrange a hose between your good self and allow this to discharge in front of the cylinder. Drink lots of water and have lots of diuretics before you go out.:rolleyes:

I think we should keep the Piss & Dribble for discussion on how to fuel inject this thing.:sweatdrop

re: #2 I rather like Amal carbs, so this one is a given.

Version PE400 3.1 - A mist spray into the airsteam. I proposed this early on, when Frits first raised the Temperature Dragons ugly head.

I did some basic googly research on this and the results were mixed. Most of it is HVAC related & not relatively high velocity airstreams
Enthalpy differences between dry & humid air - the humid air already has more heat energy than dry, for example.
It takes more energy to raise the temperature of moist air than dry, blah blah.
Actually I think that is the solution. Heating the moist air takes more energy. (From the engine and then the airflow carries it away).

If I really had to, I could carry say, 20 litres of water to spray at the engine. (does one litre of ambient temp water mist cooling = 3 or 4 of hot recirculated water??)
and then perhaps I could spray some on the pipe, on gear changes, to lower the frequency and fill in the acceleration gaps caused by the extra weight



cheers, Daryl.

[Grumph]

Know anyone in the aussie V8 supercar teams - or the GT endurance series ? Both routinely use water spray on brakes.
I believe there's quite a bit of hardware for it available over the counter.
You don't have to re-invent the wheel.

[WilDun]

Shit! - This is mind blowing stuff ........... and I thought I was going to be able to walk in and show you all how a two stroke should be designed - how wrong I was! :facepalm: rubber cylinders, body fluid cooling, - what next?...:scratch:... the possibilities are limitless! :confused:

[Pursang]

Know anyone in the aussie V8 supercar teams - or the GT endurance series ? Both routinely use water spray on brakes.
I believe there's quite a bit of hardware for it available over the counter.
You don't have to re-invent the wheel.

Actually...I do. I was in the Walkinshaw pit for the Bathurst 12hr.

331575


Shit! - This is mind blowing stuff ........... and I thought I was going to be able to walk in and show you all how a two stroke should be designed - how wrong I was! :facepalm: rubber cylinders, body fluid cooling, - what next?...:scratch:... the possibilities are limitless! :confused:

Limited only by Imagination, Time, Money...and Newtonian physics.

Next? Quantum engines, they Will be mind blowing. :wacko:

[Mental Trousers]

Next? Quantum engines, they Will be mind blowing. :wacko:

Is the piston going up or down?? Both!! :facepalm:

[Grumph]

Is the piston going up or down?? Both!! :facepalm:

Schrodinger had something to say about that - but he couldn't tune his way out of a cardboard box.....

[Pursang]

Is the piston going up or down?? Both!! :facepalm:

Two strokes, but they're doing exactly the same thing, in different places, at the same time. (Most commonly occurs on (any) Sunday).:sunny:

Cheers, Daryl

[Frits Overmars]

Schrödinger had something to say about that - but he couldn't tune his way out of a cardboard box.....He had help
331578

[WilDun]

Think maybe all this stuff is becoming way too highbrow for me!
I was hoping to dumb it all down when I asked the perfectly simple, logical (and innocent) question a while back but got no reply,.... which was, whether the good old (compact) SV engine might still be compatible with hydrogen or HCCI?? well, it makes as much sense as an all Iron two stroke .... eh Daryl
I asked this because the SV combustion chamber shape when you look at it is probably nowhere near as ugly and misshapen as your average high compression OHC four valve arrangement, or the Wankel - and the engine would be nowhere near as tall!

[Grumph]

He had help

From when we bred Burmans....

Will - I suspect that a sidevalve combustion chamber is the worst possible shape to encourage combustion.
While the current 4V chambers consist of basically the valve cutaways in the piston crown - and a dimple for the plug - at least the flame path is short.

[pete376403]

Know anyone in the aussie V8 supercar teams - or the GT endurance series ? Both routinely use water spray on brakes.
I believe there's quite a bit of hardware for it available over the counter.
You don't have to re-invent the wheel.

Tyrrell did watercooled brakes in F1 years ago, not because the brakes needed cooling, but because they could dump a whole lot of weight as soon as the race started. Cars had to be weighed after the race, but regs allowed that they could be topped up with consumed fluids before weighing.

[husaberg]

Is the piston going up or down?? Both!! :facepalm:

LOL
Heisenberg's Uncertainty Principle states that there is inherent uncertainty in the act of measuring a variable of a particle. Commonly applied to the position and momentum of a particle, the principle states that the more precisely the position is known the more uncertain the momentum is and vice versa.

[WilDun]

From when we bred Burmans....

Will - I suspect that a sidevalve combustion chamber is the worst possible shape to encourage combustion.
While the current 4V chambers consist of basically the valve cutaways in the piston crown - and a dimple for the plug - at least the flame path is short.

Aaaaaaaww, isn't that cat so innocent and .....well......just lovely! - Yeah well, "ahem" anyway, (deep gruff voice), HCCI doesn't have a flame path unless I'm mistaken.!

[Pursang]

Think maybe all this stuff is becoming way too highbrow for me!
I was hoping to dumb it all down when I asked the perfectly simple, logical (and innocent) question a while back but got no reply,.... which was, whether the good old (compact) SV engine might still be compatible with hydrogen or HCCI?? well, it makes as much sense as an all Iron two stroke .... eh Daryl
I asked this because the SV combustion chamber shape when you look at it is probably nowhere near as ugly and misshapen as your average high compression OHC four valve arrangement, or the Wankel - and the engine would be nowhere near as tall!

I know little of hydrogen, and less of HCCI, but have delved into flat-heads.

They can be made to work rather well.
You can put whatever cam you like in them and your valves will never interfere with each other, or hit the piston.
The valves can be considerably larger than any 2V OHV can fit in the cylinder, except perhaps a pure Hemi head.
You can have 100% squish if you want to.

Probably controversial but, I think this an application where a Singh groove could be useful. In a side valve engine with a lot of squish, combustion starts and burns in the chamber but then it must travel, pretty slowly, all the way across the top of the piston. My thought is that the groove provides a warmer & denser volume (less quenched) path that allows the ignition to travel quicker than the normal flame front to ignite gasses at the far end of the piston, before it is too late for them to add any value.

I guess hydrogen could also speed that up, it goes Pop! not Whoomph!


Cheers, Daryl:dodge:

[WilDun]

Probably controversial but, I think this an application where a Singh groove could be useful. In a side valve engine with a lot of squish, combustion starts and burns in the chamber but then it must travel, pretty slowly, all the way across the top of the piston................ the groove provides a warmer & denser volume (less quenched) path that allows the ignition to travel quicker than the normal flame front to ignite gasses at the far end of the piston, before it is too late for them to add any value.

Daryl, I realise that I probably don't know a helluva lot really (doesn't stop me thinking or talking though).... but it appears that with HCCI, there is no spark plug needed to initiate combustion,(at least in the running mode, as opposed to starting mode which may require a spark). So there is not actually any flame front, combustion is instantaneous. When it has reached the correct temperature and pressure, it ignites (all through the chamber) and does not have to spread, as it would do in a normal engine, so possibly there doesn't need to be a "trench" to conduct it across to the other side. That's my thinking but maybe someone else can veryify that for me.

[Pursang]

Tyrrell did watercooled brakes in F1 years ago, not because the brakes needed cooling, but because they could dump a whole lot of weight as soon as the race started. Cars had to be weighed after the race, but regs allowed that they could be topped up with consumed fluids before weighing.

It always pays to Read the Rules Very Carefully. As Smokey Yunick said (and lived and raced), 'It's not cheating unless they actually say you can't do it'. :2thumbsup

[Pursang]

Daryl, I realise that I probably don't know a helluva lot really (doesn't stop me thinking or talking though).... but it appears that with HCCI, there is no spark plug needed to initiate combustion,(at least in the running mode, as opposed to starting mode which may require a spark). So there is not actually any flame front, combustion is instantaneous. When it has reached the correct temperature and pressure, it ignites (all through the chamber) and does not have to spread, as it would do in a normal engine, so possibly there doesn't need to be a "trench" to conduct it across to the other side. That's my thinking but maybe someone else can veryify that for me.

This might be the problem, the SV squish does a few important things:

A) It pushes the mixture across into the valve/combustion chamber.

B) It attempts to produce a "reasonable" Compression Ratio.
(really hard to do Hi Comp. & maintain decent intake flow at the same time)

C) Creates a sudden lower pressure zone above it, as it heads south.

D) It keeps the top of the piston cool, by:
a) pushing away the warming (by compression) mixture and:
b) by close proximity to the cool head surface and;
c) By shielding the piston from the main combustion.
d) C) above.

And that's the rub, the gasses trapped above the piston are way cooler than those in the chamber and might not be able to ignite at the same time.

I know a little about SV engines.....But I truly know nothing of HCCI.

Plenty of scope for experimentation though, test engines are plentiful and cheap. Bit like Victas.

Cheers, Daryl.

[husaberg]

This might be the problem, the SV squish does a few important things:

A) It pushes the mixture across into the valve/combustion chamber.

B) It attempts to produce a "reasonable" Compression Ratio.
(really hard to do Hi Comp. & maintain decent intake flow at the same time)

C) Creates a sudden lower pressure zone above it, as it heads south.

D) It keeps the top of the piston cool, by:
a) pushing away the warming (by compression) mixture and:
b) by close proximity to the cool head surface and;
c) By shielding the piston from the main combustion.
d) C) above.

And that's the rub, the gasses trapped above the piston are way cooler than those in the chamber and might not be able to ignite at the same time.

I know a little about SV engines.....But I truly know nothing of HCCI.

Plenty of scope for experimentation though, test engines are plentiful and cheap. Bit like Victas.

Cheers, Daryl.
I Have posted stuff about the KR harleys before somewhere, they took what ricardo found 30 years before and made a better lemon.
The other advantage at the time was their valves didn;t get tangled and they had near direct valve actuation

[WilDun]

There you go, and I thought I knew it all!
Must say that as far as being able to take huge forces is concerned, I'd go for the Victa before the B&S!- but then, like the old Harleys, the B&S plodded on forever without actually making any progress in the performance department, bringing in a steady income by just doing......... nothing!

[Pursang]

I Have posted stuff about the KR harleys before somewhere, they took what ricardo found 30 years before and made a better lemon.
The other advantage at the time was their valves didn;t get tangled and they had near direct valve actuation

The other "advantage" they introduced was having the Rules written to ensure that it was almost impossible for any other manufacturer, with better technology, to be competitive in the premier class. (from 1946 to 1963, when Dick Mann won on a trick, fast 500cc BSA single).

Happened back in the 30's too. After the board tracks finished up, 350 & 500cc speedway & long-track was quite huge in the States, 'til the depression.

Croker had the really smick bikes, HD & Indian had factory teams competing all over the country on speedways and horse racing tracks.

With the depression hurting sales, HD & Indian decided they would sell more V-twin production bikes, if that's what the people saw racing.
Had the rules written how they wanted, killed off the trick, fast 500 singles. Bugger all M/C speedway in the USA, til the 70's.

In Oz, NZ, Britain & parts of Europe, 500cc singles were the premium models and speedway continued.

Hard to imagine that a manufacturer could have "the rules" changed in order to promote only the type of motorcycles they produce & sell.

Cheers, Daryl

PS. I actually love what American flat track racing eventually evolved into, er! 450 singles,
but imagine them trying to catch a Bultaco Astro with a modern technology 2 stroke engine (2T's were banned in 1987).

[Michael Moore]

It always pays to Read the Rules Very Carefully. As Smokey Yunick said (and lived and raced), 'It's not cheating unless they actually say you can't do it'. :2thumbsup

That depends on how they write the rules. Some organizations say "everything not specifically allowed is prohibited" while others are of a style of "if not specifically prohibited it is allowed."

[guyhockley]

He had help
331578
So now my browsing history shows I looked at a picture called "Pussy tuning"...

[Frits Overmars]

That depends on how they write the rules. Some organizations say "everything not specifically allowed is prohibited".Yeah, those are the rules where you are not allowed to inflate your tires because that's not in the book.


Hard to imagine that a manufacturer could have "the rules" changed in order to promote only the type of motorcycles they produce & sell.Come on Dary, you know you can do it if you try.
331592

[Niels Abildgaard]

This might be the problem, the SV squish does a few important things:

A) It pushes the mixture across into the valve/combustion chamber.

B) It attempts to produce a "reasonable" Compression Ratio.
(really hard to do Hi Comp. & maintain decent intake flow at the same time)

C) Creates a sudden lower pressure zone above it, as it heads south.

D) It keeps the top of the piston cool, by:
a) pushing away the warming (by compression) mixture and:
b) by close proximity to the cool head surface and;
c) By shielding the piston from the main combustion.
d) C) above.

And that's the rub, the gasses trapped above the piston are way cooler than those in the chamber and might not be able to ignite at the same time.

I know a little about SV engines.....But I truly know nothing of HCCI.

Plenty of scope for experimentation though, test engines are plentiful and cheap. Bit like Victas.

Cheers, Daryl.

Make it a two stroke HCCI SV and nobody knows anything.

http://i.imgur.com/Iz3tD97.jpg

or even more useless:A two stroke Harley

http://i.imgur.com/kgeUWsJ.jpg

[WilDun]

The other "advantage" they introduced was having the Rules written to ensure that it was almost impossible for any other manufacturer, with better technology, to be competitive in the premier class. ...........Hard to imagine that a manufacturer could have "the rules" changed in order to promote only the type of motorcycles they produce & sell.

Honda, Dorna, MotoGP.



PS. I actually love what American flat track racing eventually evolved into, er! 450 singles,
but imagine them trying to catch a Bultaco Astro with a modern technology 2 stroke engine (2T's were banned in 1987).

Honda again?

But ....... to show that I'm not biased in any way, I have an old Honda CRV car which rattles along nicely! (and it's not a two stroke!).

[WilDun]

Make it a two stroke HCCI SV and nobody knows anything.

Yes, well maybe I'll have to rewind and think it over!


or even more useless:A two stroke Harley

That'd be like when the Gods came to earth and mixed with mankind! - Look what happened after that! - God forbid!

[Grumph]

It always pays to Read the Rules Very Carefully. As Smokey Yunick said (and lived and raced), 'It's not cheating unless they actually say you can't do it'. :2thumbsup

Ron Grant is said to have had that up on the wall in the Honda Britain workshop - where they cut and welded a VFR750 crank to change the firing order...In "Superstocks"....

I've lived by it too - which has resulted in some, "interesting discussions," with officialdom over the years, LOL.

One of my old friends - now dead - was on the CIK Commission as the rep from this part of the world. I always had him on about the CIK rules being of the type where you couldn't do it unless they said you could...He'd agree, then go away to find a way of tightening the rules further...

[WilDun]

Yeah, those are the rules where you are not allowed to inflate your tires because that's not in the book.

Those who religiously follow the rules hinder evolution, those who defy the rules progress (or die).


Come on Dary, you know you can do it if you try.
331592

Like the Victa and the Harley it's Iron! (and the world's best selling motorcycle!).

[Pursang]

Does that mean that you have seen the light and are switching to watercooling Daryl? In that case the good news is that you don't need 60 litres per minute; the rule of thumb is one litre per crankshaft-HP per minute. .

As a gesture to Common Sense, the Laws of Thermodynamics, and out of respect for Great Advice, given warmly and freely.......

...AND.... In the absence of Any Rules that dictate otherwise.. The Victa will be Water-cooled!!!

I've spent some time on this and think I have something reasonably practical, that I can turn up at home, from a 50mm length of 120mm diam. aluminium billet.
331600

It's not perfect, and somebody might say: "I'd rather say they had a water cooled head cover. Coolant in the cylinder was hardly moving; cooling below the exhaust was non-existent. Not the best solution if you want reliable power." or something like that.

It will be no harder than casting and machining a decent air cooled one.
It will reduce the air cooling requirement, (or at least transport a fair percentage of it to a radiator).

A water-cooled exhaust duct will be a much tougher fabrication.

Transfers (whatever they'll look like) can hang in the breeze, for now.

cheers, Daryl

[Grumph]

Google "Dent water cooled conversion" Daryl. I can't post a link sorry - but it's in a vintage kart club site.
Similar to what you're doing but the alloy pipe seats on the lowest fin left on the barrel - and the head is air cooled.
As someone will say - it looks like sitting the barrel in a bucket of water - but it worked.
There's no sin in leaving the head air cooled - MZ's were like that for quite a while.

[Pursang]

Took a little finding..Link is here. http://www.trhkc.com/the-special-builders.html

Really fascinating, if you're interested in how very advanced some kart builders were, back in the 60's.

Who knows where karts would be now if suspension wasn't prohibited and/or there was a Formula Libre for karts.

Here's some pics of the Dent Special with self water-cooled Villiers.
331608331610 331609

cheers, Daryl

[Pursang]

It's an Amazing thing about Kiwi Biker

No sooner does one post a (brilliant) idea, but someone out in the real world has done it.

Water-cooled YZ490

331611

331612

"I'd rather say they had a water cooled head cover. Coolant in the cylinder was hardly moving; cooling below the exhaust was non-existent. Not the best solution if you want reliable power." or something like that.

Cheers, Daryl.

[guyhockley]

Google "Dent water cooled conversion" Daryl. I can't post a link sorry - but it's in a vintage kart club site.
Similar to what you're doing but the alloy pipe seats on the lowest fin left on the barrel - and the head is air cooled.
As someone will say - it looks like sitting the barrel in a bucket of water - but it worked.
There's no sin in leaving the head air cooled - MZ's were like that for quite a while.

http://www.kartbook.net/group/vintagehistorickarts?commentId=2879226%3AComment%3 A791662&xg_source=activity
for the aircooled head?
Long thread, good job none here go on that long....

[guyhockley]

Surely this must be the same Mark Mansell as the Victa kart bloke?
http://www.onthewire.co.uk/mm10cc.htm

[Grumph]

Daryl, if you're looking at running the Victa at Lake Gardener - with the known high ambient temps there - you may have a problem with straight water cooling.
It may be worth looking at pumping through a coil in an icebox - or going back to the waterspray as that might give a better return in terms of barrel temp reduction.

[Pursang]

Daryl, if you're looking at running the Victa at Lake Gardener - with the known high ambient temps there - you may have a problem with straight water cooling.
It may be worth looking at pumping through a coil in an icebox - or going back to the waterspray as that might give a better return in terms of barrel temp reduction.

Cool,:cold: no radiator out in the airstream either, that'll save some horses. Got to get through a Queensland Summer of testing first.:sweatdrop:

Cheers., Daryl.

[Pursang]

After a couple of days of intense study & re-study, I feel like I'm almost, nearly, starting to get IT!

Frits has explained it so many times, in so many ways, to so many people, he deserves a Medal, or a Nobel.

It seems to be all about the "Juggle" between the Blow-down STA & Transfer STA .
And not any old STA, not Jennings, Blair, Bell, et al.
The current Optimum STA's were developed in the RS125.

The juggle comes in the angle.area part.
Creating plenty of port area enables you to reduce the angle (duration),
That reduces your port height,
That reduces your area,
That reduces your TA.....and you start again.

Blowdown STA is causing me some concern .
As far as I can tell, the 'Angle' only applies to the portion of down stroke above the transfer opening?
(Unlike transfer angle(duration) that is functional with the piston going down and up)

I'm developing an excel work sheet to help with the juggle, if not mathematically, perhaps by graphing to indicate the "sweet spot"

If any one has an Excel formula to calculate port height from duration, and would be willing to share, it would be much appreciated. The one I'm using seems to be' haunted' and constantly referring to the on-line ones is awkward.

Cheers, Daryl

[Pursang]

Here's a very hypnotic graphic that clearly demonstrates the differences in piston motion with even small changes in stroke.


331688

Attribution:
By Patrhoue - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=16032659

[Pursang]

Got it::woohoo: For some reason it was recognising PI() as a legitimate function and then ignoring it in the calculation.

Now looks like this: =(C2/2)*COS(C28*3.1416/180)+SQRT((C3^2)-((C2/2)^2)*(SIN(C28*3.1416/180))^2)-(C2/2)-C3+C2

C2 is the stroke C3 is conrod length.

Cheers, Daryl.

[Pursang]

So here is my transfer STA worksheet.

331692

Not surprisingly, it conforms with Frits' earlier recommendations, regarding transfer circumferential length, timing and a realistic RPM.:yes:
(It just takes a bit of a mental shift, to move on from 40 years of 40 year old two stroke theory & practice).

Thank-you Very Much, :first:

Cheers, Daryl

[husaberg]

If any one has an Excel formula to calculate port height from duration, and would be willing to share, it would be much appreciated. The one I'm using seems to be' haunted' and constantly referring to the on-line ones is awkward.

Cheers, Daryl

bell and robinson have simple formulas for port height +duration as do jennings.
Robinson is in BBC though lol
pretty sure there is a Prof blair site with a calculator
or just get a copy of eng2mod
http://vannik.co.za/EngMod2T.htm

i think what you might find is the duration figures that Bell used together with the widths generally still fall into line with current ideals.
the greatest gains were made with shapes of ports and transfers.
I seem to recall Frits saying port timing on the aprilias was pretty much static for about 15 years.

[Pursang]

Yes I will have to get EngMod2T, I even watched adegnes's Video walk-through, very helpful.

I will need to cull some other projects, to be able to drop the cash.

The timings seem identical to AG Bell, but those were intended to make the power at 10,000+ rpm.

The Optimum STA's should enable the same, or more, power with a pipe designed for 7,500-8,000.

Efficient Transfer ducts, holding the head down (and as already determined, managing all the extra heat) will be challenges.

But also, I'm not trying to make 50+ hp for an hour, just 20 at the wheel for a few minutes.

Plus I can use methanol and supercharging, if necessary.

cheers, Daryl.

[husaberg]

Here's a very hypnotic graphic that clearly demonstrates the differences in piston motion with even small changes in stroke.


331688

Attribution:
By Patrhoue - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=16032659

331735 plus 10....

[Frits Overmars]

After a couple of days of intense study & re-study, I feel like I'm almost, nearly, starting to get IT!
Frits has explained it so many times, in so many ways, to so many people, he deserves a Medal, or a Nobel.
Blowdown STA is causing me some concern. As far as I can tell, the 'Angle' only applies to the portion of down stroke above the transfer opening? (Unlike transfer angle(duration) that is functional with the piston going down and up)You grasped it.


I'm developing an excel work sheet to help with the juggle, if not mathematically, perhaps by graphing to indicate the "sweet spot". If any one has an Excel formula to calculate port height from duration, and would be willing to share, it would be much appreciated. The one I'm using seems to be' haunted' and constantly referring to the on-line ones is awkward.The math isn't that complicated Daryl. Here you go:
331739
But the real problem is that port windows are not always simple rectangles; their chordal width may vary with piston position, which will make your Excel job a lot more complicated.

BTW: I've got a couple of medals but a Nobel prize is still missing. Do you happen to know anybody in Sweden? :p

[Pursang]

You grasped it.

Thanks to you.

The math isn't that complicated Daryl.

No, I got the math. The complication was Excel not playing PI

But the real problem is that port windows are not always simple rectangles; their chordal width may vary with piston position, which will make your Excel job a lot more complicated.

Quite right, and I assume using the geometric centre of the transfer area doesn't account for the piston slowing down and stopping at BDC.
Still, I'm not trying to re-invent EngMod. What it has done is allow a simple play around with the numbers, to prove the concept & the potential.
Now I want to look at a couple of other older engines in the stable.

A copy of EngMod2T is now sitting at the top of the shopping list.

BTW: I've got a couple of medals but a Nobel prize is still missing. Do you happen to know anybody in Sweden? :p

??? 331750 Cheers, Daryl.

[Frits Overmars]

331750
Now I want to look at a couple of other older engines in the stable.
In case you want to extract the angle.area values from those older engines: don't; it will blurr your view.
Here is something a little less vintage, that I posted on the French Pit-Lane forum: http://www.pit-lane.biz/t6246p25-gp125-all-that-you-wanted-to-know-on-aprilia-rsa-125-and-more-by-mr-jan-thiel-and-mr-frits-overmars-part-5
331772

PS: did Agnetha, Björn, Benny and Anni-Frid really make it to the Nobel Committee? I think I like their music after all :p.

[Pursang]

In case you want to extract the angle.area values from those older engines: don't; it will blurr your view.

Not to use them as examples of good practice, but to determine if additional transfer, blow-down and a FOS pipe could be usefully & practically applied.

Here is something a little less vintage, that I posted on the French Pit-Lane forum: http://www.pit-lane.biz/t6246p25-gp125-all-that-you-wanted-to-know-on-aprilia-rsa-125-and-more-by-mr-jan-thiel-and-mr-frits-overmars-part-5
331772

Thanks for that, I had read your words and put my interpretation into the worksheet. But I'm not a member, so couldn't see the illustration.
The effective areas are very clear, but it was probably of some value to work it out myself.
The rates of change of area, due to piston motion, are not as important as I expected. But I will pay attention to my chords.

A couple of other questions from that post:

130 transfers, no stagger. Does that mean engines that operate better with stagger probably have less than optimum port directions/dimensions?

The 'mirror' of the blow-down (the blow-back?). This is the ideal time for the pipe to push charge back into the cylinder.
Does extending the Ex duration (within reason) actually allow the pipe to be effective over a broader range of RPM & temp? (A bit contrary to accepted theory.)

PS: did Agnetha, Björn, Benny and Anni-Frid really make it to the Nobel Committee? I think I like their music after all :p.
No, but I bet they know some-one who is, just a couple of degrees of separation might be all you need

Cheers, Daryl.

[Frits Overmars]

130 transfers, no stagger. Does that mean engines that operate better with stagger probably have less than optimum port directions/dimensions?I would not be so bold as to confirm your supposition unconditionally. But I like to keep things surveyable (all transfer port equally high) and I know that in the case of the Aprilia the A-transfers could not be made any higher without eating into the real estate of the auxiliary exhaust windows.
I would also recommend reading through Wobbly's views on stagger.


The 'mirror' of the blow-down (the blow-back?). This is the ideal time for the pipe to push charge back into the cylinder.
Does extending the Ex duration (within reason) actually allow the pipe to be effective over a broader range of RPM & temp? (A bit contrary to accepted theory.)That might well the case Daryl. If there is a bigger time window between transfer closure and exhaust closure, the pipe has a broader opportunity to push charge back into the cylinder. But the exhaust timing itself cannot be raised at will. For true resonance we need an effective duration of 180° which would work out at a geometrical timing of about 190°. However, in some cases a higher exhaust timing may be needed to strike the best compromise between resonance and blowdown angle.area.

This line of thought leads to the conclusion that the transfers should not be made any higher than strictly necessary. The lower they are, the less risk of washed-through mixture and even spent gases getting pushed back into the transfer ducts and into the crankcase. 130° gives a good balance between maximizing the transfer angle.area, minimizing this risk and maximizing the time window between transfer closure and exhaust closure.
This is one more reason to avoid stagger: stagger will only partially help the transfer angle.area but the highest transfer port will determine the gravity of the above-mentioned risk.

[Pursang]

Transfer angle.area determines the effective (torque peak) rpm.

Many/most/all 'vintage' competition engines are transfer a.a deficient and make their power by multiplying the reduced torque by as many revs as possible.
Of course they are also blow-down a.a deficient as well, this is partially compensated by 'hogged out' Ex ports that can continue blowing-down into the transfer period, further reducing the effective Tr a.a. (It gets worse & worse, the more you think about it :facepalm:........but just 'cos they're not perfect, doesn't mean they're not Fun :ride:)

Q: For engines limited by the available Tr a.a, (ie. below Optimum STA) should the Blow-down STA be reduced (if necessary) to match, or be as close to Optimum as possible?


Cheers, Daryl

[Pursang]

Q: For engines limited by the available Tr a.a, (ie. below Optimum STA) should the Blow-down STA be reduced (if necessary) to match, or be as close to Optimum as possible?


After re-reading, I think I might have answered my own question::o

If the Tr a.a is limited, I should aim for Optimum blow-down, to minimise any transfer obstruction/delay and even, perhaps, give it a "head start" by creating negative cylinder pressure well before TPO.

I haven't seen any EngMod2T traces that look like that. They all seem to be just on, or over, the edge of pressurising the transfers.

Cheers, Daryl

[Frits Overmars]

Many/most/all 'vintage' competition engines are transfer a.a deficient and make their power by multiplying the reduced torque by as many revs as possible. Of course they are also blow-down a.a deficient as well, this is partially compensated by 'hogged out' Ex ports that can continue blowing-down into the transfer period, further reducing the effective Tr a.a.
(It gets worse & worse, the more you think about it :facepalm:.......Ain't that the truth. Just keep on thinking: if the blowdown a.a does not alllow the cylinder pressure to drop below crankcase pressure by the time the transfers start opening, the exhaust gases will relentlessly abuse the transfers as auxiliary exhausts. Only when the cylinder pressure has dropped far enough, can the transfer phase begin. And what is being transferred first? The exhaust gases that filled the transfer ducts! Only after the transfer ducts have cleared their throats, can the transfer of fresh mixture begin. In short: insufficient blowdown a.a. will eat doubly into the transfer a.a.


just 'cos they're not perfect, doesn't mean they're not Fun :ride:Ain't that true too. Internal combustion engines are hopelessly inefficient compared to electromotors (if you take the availability of electricity for granted...).
But which is more fun? Gimme combustion any time :D.


After re-reading, I think I might have answered my own question.You did :niceone:.

[Pursang]

Internal combustion engines are hopelessly inefficient compared to electromotors (if you take the availability of electricity for granted...).


331801 Reliable electricity anywhere, any time, just need some petrol.

cheers, Daryl

[lohring]

[QUOTE=Frits Overmars

Ain't that true too. Internal combustion engines are hopelessly inefficient compared to electromotors (if you take the availability of electricity for granted...).
But which is more fun? Gimme combustion any time :D.

You did :niceone:.[/QUOTE]

You can have fun with electrics as well, but it's a different game. This 2008 record (https://www.youtube.com/watch?v=-yNu2_LlO9s) we set still stands but think what you could do with a 2017 electric power plant.

Lohring Miller

[Pursang]

Hi Lohring,

That record run was impressive, especially considering the Voltage & Motor restrictions.

At least brushed motors make a pretty cool noise when they're winding up & running Flat Out!

That other stuff you do is pretty cool too! :2thumbsup

Cheers, Daryl.

[lohring]

Most of the noise was from the quick change gears. We wanted to run proven props and they turn around 10,000 rpm on IC outboards. The brushed motor we used was limited to 5,000 rpm. Mike Bontoft designed and built a great gear box using standard quick change gears that allowed us to match the motor to the prop. We changed the gears several times before we topped out the speed at a little over 100 mph. It wasn't quite enough to get a two way run to average over 100. It took a few batteries, but they were a lot lighter than the lead acid batteries that were used previously.

Lohring Miller

331811 331810 331812

[Grumph]

Very neat. Not the first time I've seen QC gears used for something odd. They can be a very handy answer to finding a source of readily available gears.

[Pursang]

No wonder I like the whine of quick change gears,
my Dad built and raced Midgets in the 50's
331821331822
Cheers, Daryl

[Grumph]

No wonder I like the whine of quick change gears,
my Dad built and raced Midgets in the 50's
Cheers, Daryl

Those pics take me back. Very similar atmosphere at the time on this side of the Tasman. Push starting race cars on grass....

The Standard Vanguard engine was not used as much as it could have been for motorsport. Triumphs obviously, but special builders didn't seem to want to use it - and it was common as they were assembled here. My old man worked at the assembly plant in ChCh as a day job.
Hec Green's ChCh built twin cam alloy race engines were built around the Vanguard crank - supplied courtesy of the old man...

[WilDun]

The Standard Vanguard engine was not used as much as it could have been for motorsport. Triumphs obviously, but special builders didn't seem to want to use it - and it was common as they were assembled here. My old man worked at the assembly plant in ChCh as a day job.
Hec Green's ChCh built twin cam alloy race engines were built around the Vanguard crank - supplied courtesy of the old man...

That engine was very good and was used in just about everything from Fergie tractors to family cats to Triumph sports cars (diesel versions too - as used in the Fergie Diesel tractors and some Taxi cars in Britain - these were very successful and the sweetest running little diesels ever, however not so well known in NZ, just in the tractors at the airports, also used in Antarctica by Edmond Hillary).
I would be interested in the twin cam alloy engine too, did he use any other Vanguard parts other than the crank? (eg the wet liners).

[Grumph]

That engine was very good and was used in just about everything from Fergie tractors to family cats to Triumph sports cars (diesel versions too - as used in the Fergie Diesel tractors and some Taxi cars in Britain - these were very successful and the sweetest running little diesels ever, however not so well known in NZ, just in the tractors at the airports, also used in Antarctica by Edmond Hillary).
I would be interested in the twin cam alloy engine too, did he use any other Vanguard parts other than the crank? (eg the wet liners).

I don't know how much of Hec's work is on line Will. He was written up in a series of articles in Classic Driver mag a few years back, they may be on line. He built a series of R.A. Specials - won the second Lady Wigram trophy race in the first.
The alloy 4cyl was twin cam, 2V per cylinder, cams driven by surplus Merlin engine gearing. Hec made rods, cams and I think pistons too.
Cast in ChCh by I think the Symonds bros who got one engine for a hydro. 2 or 3 survive. A guy I know has the last RA Special tucked away. Hec didn't want it brought out at the modern classic meets for some reason. He and his business partner, Jack Brewer - who ran the Lady Wigram meeting for years - and my old man were close mates. All 3 were AMIMechE qualified and represented a think tank of no mean ability.
Actually, memory has just kicked in, Hec's first rear engined car was the RA Vanguard. Supercharged and on alky, it was quick enough that when Geoff Mardon had it, he qualified on the front row for the Dunedin street race against the internationals. Officialdom didn't believe the times and put him well back. He was going up through the field very quickly when a wheel broke...Same thing happened to Les Moore (Ronnie's father) but it killed Les that time.

Here's a pic for Daryl - just to whet your ambition....

[robajs]

a thinner version of you grumph!!!!!!!!!!!!:wings:

[Grumph]

a thinner version of you grumph!!!!!!!!!!!!:wings:

I am jealous of that beard....

[pete376403]

No wonder I like the whine of quick change gears,
my Dad built and raced Midgets in the 50's
Cheers, Daryl


So is that Vic Tracey any relation to Ted Tracey, who used to be pretty big in Auckland speedway? (Ted Tracey Motors)

[Jannem]

In case you want to extract the angle.area values from those older engines: don't; it will blurr your view.
Here is something a little less vintage, that I posted on the French Pit-Lane forum: http://www.pit-lane.biz/t6246p25-gp125-all-that-you-wanted-to-know-on-aprilia-rsa-125-and-more-by-mr-jan-thiel-and-mr-frits-overmars-part-5
331772

PS: did Agnetha, Björn, Benny and Anni-Frid really make it to the Nobel Committee? I think I like their music after all :p.

Perfect!:headbang:

I had seen the graph and have those area numbers as reference in my spredsheet, but hadn't seen the text with the real meat. Thank You!

[Lightbulb]

In case you want to extract the angle.area values from those older engines: don't; it will blurr your view.
Here is something a little less vintage, that I posted on the French Pit-Lane forum: http://www.pit-lane.biz/t6246p25-gp125-all-that-you-wanted-to-know-on-aprilia-rsa-125-and-more-by-mr-jan-thiel-and-mr-frits-overmars-part-5
331772

PS: did Agnetha, Björn, Benny and Anni-Frid really make it to the Nobel Committee? I think I like their music after all :p.

Frits,if this idea is applied to the MB40 engine, what numbers do you get. I now have an MB40 engine, and can measure the transfer are and timing and the exhaust, so will be able to follow the example better. Your above example I am not able to follow sorry.
Neil

[Jannem]

In case you want to extract the angle.area values from those older engines: don't; it will blurr your view.
Here is something a little less vintage, that I posted on the French Pit-Lane forum: http://www.pit-lane.biz/t6246p25-gp125-all-that-you-wanted-to-know-on-aprilia-rsa-125-and-more-by-mr-jan-thiel-and-mr-frits-overmars-part-5
331772

PS: did Agnetha, Björn, Benny and Anni-Frid really make it to the Nobel Committee? I think I like their music after all :p.

Plugged the numbers in and was puzzled about getting about 2x the Aprilia values from my cylinder. Then noticed that the picture says effective areas... Am I correct to assume I should use the classic mean (angle) area for the calculations?

[guyhockley]

Here's a pic for Daryl - just to whet your ambition....

Bit further on.

[Frits Overmars]

Plugged the numbers in and was puzzled about getting about 2x the Aprilia values from my cylinder. Then noticed that the picture says effective areas... Am I correct to assume I should use the classic mean (angle) area for the calculations?Plugged the numbers in where?
You may also want to take another look here, regarding your mean area: https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1131055378#post1131055378

Come to think of it, maybe a more fundamental explanation may be in order:

Blowdown angle.area

Blowdown angle.area is not simply the total blowdown area multiplied by the total blowdown angle. It is the sum of a lot of small area steps, multiplied by the time during which each of these steps is open.

For example, let us assume that the exhaust port is a simple rectangle, 40 mm wide, that it opens 1 mm further for each degree of crankshaft rotation, and that the total blowdown angle from the point where the exhaust port is beginning to open till the point were the transfer ports are beginning to open, is 30°.
Then the first degree of exhaust opening will open an area of 40 mm x 1 mm = 40 mm², and this area will be open during the whole 30° of blowdown period. That first area thus has an angle.area of 30° x 40 mm² = 1200°mm².

When the crankshaft turns 1 degree further, an additional area of 40 mm² is opened. This second area will be open during 29°, so its angle.area is 29° x 40 mm² = 1160°mm².

Repeat this calculation for each crank degree until the end of the blowdown phase, and add all the angle.area values; that will give you the total blowdown angle.area.

In reality this calculation is complicated by the fact that not every degree of crank angle gives the same port height difference, and even more complicated by the fact that the exhaust port is not a simple rectangle. But you will understand the principle of angle.area.
================================================== ==============================

Transfer angle.area

Let us assume a transfer port with a timing of 130°.
When you turn the crank 1º past Transfer Open, a certain area of port, say A1, will be exposed. I don't know or care what that area is, that's for you to measure.
That area of port A1 will be open for 130º. The angle.area for this area A1 is = 130 x A1.
Turn the crank another 1º and an additional area of port, A2, will be opened.
This additional area A2 will be open for 128º. The angle.area for this area is = 128 x A2.
The next degree of crank rotation will open Area A3 which will be open for 126º and its angle.area will be 126 x A3.
Keep going like this until BDC, then add up all the angle.areas you have calculated.
The total is the angle.area for that transfer port.

[Pursang]

So is that Vic Tracey any relation to Ted Tracey, who used to be pretty big in Auckland speedway? (Ted Tracey Motors)

The Tracey was Fred Tracey, former Solo rider and then promotor.
(Vic) was for Victorian Drivers.

331834

Cheers, Daryl

[Frits Overmars]

Frits,if this idea is applied to the MB40 engine, what numbers do you get. I now have an MB40 engine, and can measure the transfer are and timing and the exhaust, so will be able to follow the example better. Your above example I am not able to follow sorry.Here you go Neil.
331833
If your MB40 engine is recent, you will have a narrower exhaust port and an accordingly smaller blowdown angle.area than the value shown in my picture.
These small methanol-burning engines have lousy carburation because the fuel is not sucked in by the air flow passing through the carb, but pushed in by means of exhaust pipe pressure exerted on the fuel bladder. Big globs of fuel enter the engine with no time at all to evaporate, so the mixture will be anything but homogeneous;
it will vary from very rich to very lean all over the place.
In order to get anything like a decent burn speed the mixture needs pre-heating by means of mixing with spent gases, so a blowdown time.area that would be too small for a bigger engine, may work better in these small screamers. It took me quite some time to grasp this...

[Pursang]

Those pics take me back. Very similar atmosphere at the time on this side of the Tasman. Push starting race cars on grass....

The Standard Vanguard engine was not used as much as it could have been for motorsport. Triumphs obviously, but special builders didn't seem to want to use it - and it was common as they were assembled here. My old man worked at the assembly plant in ChCh as a day job.
Hec Green's ChCh built twin cam alloy race engines were built around the Vanguard crank - supplied courtesy of the old man...


That engine was very good and was used in just about everything from Fergie tractors to family cats to Triumph sports cars (diesel versions too - as used in the Fergie Diesel tractors and some Taxi cars in Britain - these were very successful and the sweetest running little diesels ever, however not so well known in NZ, just in the tractors at the airports, also used in Antarctica by Edmond Hillary).
I would be interested in the twin cam alloy engine too, did he use any other Vanguard parts other than the crank? (eg the wet liners).

Dad fitted the Vanguard in the early 50's, replacing a 4cyl Chrysler. He worked at a big Standard dealership. The engine block was rescued from the rubbish bin, it had thrown a rod out the side and had been replaced under warranty. The block was patched, the rest was usable. It was pretty high tech at the time, most midgets still ran Model A, V-8 60, Jeep, Studebaker's & JAP V-twins. They quickly discovered it's deficiencies for racing. First problem was the valve spring retainers, these were a stepped ring with a slotted hole to fit into the groove in the valve. Uniquely, the longer outer 'retaining' spring was quite soft and the inner was the strong one. Clever idea for easy assembly & quiet operation, but highly likely to spit out the retainers and drop valves when revved. Early crankshafts were soft and needed nitriding to prevent journals going out of round. The cylinder head has a large water passage over the gap in the liners between 2 & 3. The gasket is only supported by the top edge of the liners and is prone to blowing out there. Although not officially sponsoring the car (except the 'under the counter' parts, especially new big end bearings, every week) the Dealer did send reports to the UK and many things were rectified by the time the Triumph versions were released (except the head gasket issue). The Vanguard was eventually replaced with the ubiquitous grey (side-plate) Holden 6 cyl.

I think I've discovered the cause of the big end bearing problem, which is good, I'm rebuilding this version of the car from original parts.

cheers, Daryl

[Pursang]

Come to think of it, maybe a more fundamental explanation may be in order:

Blowdown angle.area

Blowdown angle.area is not simply the total blowdown area multiplied by the total blowdown angle. It is the sum of a lot of small area steps, multiplied by the time during which each of these steps is open.

Ah ha! 331835

[Pursang]

Here's a pic for Daryl - just to whet your ambition....


Bit further on.

I really hope that just one cylinder will be enough to do the job.:p

Cheers, Daryl.

[Lightbulb]

Thanks Frits, that explains a lot more. Yeah the fuel delivery is really bad, and efforts to make it better a atomisation for the effort did not deliver any more power. Part of that could be that when it does get a better atomisation, then requires a larger blow down more approaching that of the petrol engines. Something that we did not try and so may have missed the boat on that testing series.
Neil

[WilDun]

When I first arrived in NZ in 1966, (51 years ago, - still can't believe it!!) - I had never seen either Motorcycle speedway or Midget Car racing and I remember that the Holdens were starting to gain control - that was way before the VW's (or derivatives of) had taken over and I was hearing the name "Offenhauser" a lot. I was told that their cylinder blocks and heads were 1 piece castings - what happened to the Offenhausers?
I never did get to see one.

[Jannem]

Plugged the numbers in where?
You may also want to take another look here, regarding your mean area: https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1131055378#post1131055378

Come to think of it, maybe a more fundamental explanation may be in order:

Blowdown angle.area

Blowdown angle.area is not simply the total blowdown area multiplied by the total blowdown angle. It is the sum of a lot of small area steps, multiplied by the time during which each of these steps is open.

For example, let us assume that the exhaust port is a simple rectangle, 40 mm wide, that it opens 1 mm further for each degree of crankshaft rotation, and that the total blowdown angle from the point where the exhaust port is beginning to open till the point were the transfer ports are beginning to open, is 30°.
Then the first degree of exhaust opening will open an area of 40 mm x 1 mm = 40 mm², and this area will be open during the whole 30° of blowdown period. That first area thus has an angle.area of 30° x 40 mm² = 1200°mm².

When the crankshaft turns 1 degree further, an additional area of 40 mm² is opened. This second area will be open during 29°, so its angle.area is 29° x 40 mm² = 1160°mm².

Repeat this calculation for each crank degree until the end of the blowdown phase, and add all the angle.area values; that will give you the total blowdown angle.area.

In reality this calculation is complicated by the fact that not every degree of crank angle gives the same port height difference, and even more complicated by the fact that the exhaust port is not a simple rectangle. But you will understand the principle of angle.area.
================================================== ==============================

Transfer angle.area

Let us assume a transfer port with a timing of 130°.
When you turn the crank 1º past Transfer Open, a certain area of port, say A1, will be exposed. I don't know or care what that area is, that's for you to measure.
That area of port A1 will be open for 130º. The angle.area for this area A1 is = 130 x A1.
Turn the crank another 1º and an additional area of port, A2, will be opened.
This additional area A2 will be open for 128º. The angle.area for this area is = 128 x A2.
The next degree of crank rotation will open Area A3 which will be open for 126º and its angle.area will be 126 x A3.
Keep going like this until BDC, then add up all the angle.areas you have calculated.
The total is the angle.area for that transfer port.

Thank You Frits, this clears it up a lot.

As for your question where I'm plugging the values, I've built up a spreadsheet with measured port and cylinder values and I'm using it to test impact of different modifications in timings and areas. Getting this nailed down is the last step to be able to have a solid target to aim for (without investing to a simulator, which is not in the cards right now).

I appreciate all the help I've got from you very much. Actually, we do, as this is a joint project with my son.

-Janne

[WilDun]

Sorry, we are talking on two different subjects here, but I guess that's the way forums work!

Just to say that I found a good picture of the Midget "Offy" engine:-
Not a head stud in sight!

331843

[Grumph]

Sorry, we are talking on two different subjects here, but I guess that's the way forums work!

Just to say that I found a good picture of the Midget "Offy" engine:-
Not a head stud in sight!

Yep, all top 1930's technology. Head and barrel in one casting, bearings for the crank on bolt-in diaphragms in the crankcase, hollow rods...

And it worked well too. Competitive right up to the 70's. And they sound bloody good on full noise too.

As an aside, a mate at Auto Restorations in ChCh was doing an Alfa P3 GP engine which is the same integral head layout last time I was in there. He showed me the OE valve guides which slipped in and were retained by the springs. Had to be like that to fit big valves up the bore and angled into the port...
He'd discovered that guides 1mm shorter would allow fitting the valves while the guides were in the head so had made up a set of shorter guides which were pressed in. Better heat transfer and valve life. He also built the Britten engines...

[Frits Overmars]

Thank You Frits, this clears it up a lot. As for your question where I'm plugging the values, I've built up a spreadsheet with measured port and cylinder values and I'm using it to test impact of different modifications in timings and areas. Getting this nailed down is the last step to be able to have a solid target to aim for (without investing to a simulator, which is not in the cards right now).
I appreciate all the help I've got from you very much. Actually, we do, as this is a joint project with my son.My pleasure Janne :rolleyes:

[guyhockley]

Yep, all top 1930's technology. Head and barrel in one casting, bearings for the crank on bolt-in diaphragms in the crankcase, hollow rods...

And it worked well too. Competitive right up to the 70's. And they sound bloody good on full noise too.

As an aside, a mate at Auto Restorations in ChCh was doing an Alfa P3 GP engine which is the same integral head layout last time I was in there. He showed me the OE valve guides which slipped in and were retained by the springs. Had to be like that to fit big valves up the bore and angled into the port...
He'd discovered that guides 1mm shorter would allow fitting the valves while the guides were in the head so had made up a set of shorter guides which were pressed in. Better heat transfer and valve life. He also built the Britten engines...
More modern iteration of the no head gasket.

[guyhockley]

Sorry, we are talking on two different subjects here, but I guess that's the way forums work!

Just to say that I found a good picture of the Midget "Offy" engine:-
Not a head stud in sight!

331843
and the bolt on water jacket could be relevant to someone on here...

[WilDun]

More modern iteration of the no head gasket.

Plenty of modern "complete" head/barrel examples in the two stroke scene, especially in chainsaws and the like. Not great for buckets though to get the squish clearances right! but then knowing our "bucketeers" they would no doubt, get round that one with head inserts!

I'm surprised that this isn't used more in production competition engines today (both two and four stroke), considering the fact that head gaskets and high compression can cause countless problems which will spoil your day, also the re-machining of a head is no simple job! (can only be done so many times as well, then it's a new head!).
The accurate machine tools we have in factories today could easily put the squish clearance problems to bed.

Pretty sure that the Moto Guzzi V8 used the "one piece" head/barrel as well, it had screwed in liners too, (with threads up top and a taper seal above them).

I reckon the Offenhauser was a good solid design, still a very strong possibility today!
Grumph's (or whoever's) idea of simplifying valve maintenance could then become the standard way of doing the valves in situ.

[Grumph]

Can't see the modern 4T production engine going back to a one piece barrel and head sorry Will. The current thinking is that block/crankcase stiffness is paramount to keep it reliable at higher revs. Plus the sheer complexity of modern 4v head castings makes it bloody hard to do it all in one piece.
Yes, things like the Hart very high boost race engines may still appear. It's even possible that the F1 engines using HCCI are done like this but it's not common now. What is becoming more common in bikes is amalgamating the crankcase and barrel as is car practice. Weight reduction and improved stiffness again.

I can quote an extreme case - Delage straight eight GP engine, Auto Restorations again. They did a "better" stiffer crank for it. Around 3 feet long - just under a meter Frits - and within a half hours running, the separate block cracked. The OE copy crank they didn't like allowed things to flex and move around quite happily.

[WilDun]

Can't see the modern 4T production engine going back to a one piece barrel and head sorry Will.........

Yes, I do understand that there would be a very good reason for not doing it that way - otherwise they would be doing it - I just I didn't know the reason! - it almost always involves cold hard cash!
Pity to see some gems disappear just because of that.


It's even possible that the F1 engines using HCCI are done like this but it's not common now.

Is HCCI actually being used in F1 now?


I can quote an extreme case - Delage straight eight GP engine, Auto Restorations again. They did a "better" stiffer crank for it. Around 3 feet long - just under a meter Frits - and within a half hours running, the separate block cracked. The OE copy crank they didn't like allowed things to flex and move around quite happily.

I believe that when the first Matchless parallel twins (500cc models) came out there were some serious crankcase cracking problems (or was it just broken cranks?) with their super stiff 3 bearing setup (unlike the 2 bearing cranks in the Triumph, Norton and BSA twins ).
Then in the Norton Commando, the big 750/850 twins were just let loose to do whatever they wanted to do in just about every conceivable way (including the engine mounts!). - They obviously hadn't heard of Dr Lanchester's ideas on balance, or just ignored them!

[Pursang]

Sorry I haven't been around for the Offy stuff (a topic I really like too).

I had to send an old friend off this week, his family asked me to write and present his eulogy.:bye:

Don Newell was a pioneer of Bultaco in Australia, and a racer to his core.
He was still competing in Classic MX at 83+ years.

Pdf copy here, if you're interested.
331850

Cheers, Daryl

[Pursang]

Don in Action, around 2 years ago, (Blue Bultaco) First to the first corner...again.:niceone:


https://www.facebook.com/guy.westerman.7/videos/1587458104610988/

Cheers, Daryl

[WilDun]

A very nice Eulogy Daryl and very informative as well! - I feel now that I actually knew the guy!

[pete376403]

I believe that when the first Matchless parallel twins (500cc models) came out there were some serious crankcase cracking problems (or was it just broken cranks?) with their super stiff 3 bearing setup (unlike the 2 bearing cranks in the Triumph, Norton and BSA twins ).
Then in the Norton Commando, the big 750/850 twins were just let loose to do whatever they wanted to do in just about every conceivable way (including the engine mounts!). - They obviously hadn't heard of Dr Lanchester's ideas on balance, or just ignored them!


Commando cranks used to flex to the extent that the main bearing rollers were running on their end edges, rather than the whole width of the roller. "Superblend" rollers were used to mitigate this - the cranks still flexed, but the bearing lived (longer)

[Pursang]

A very nice Eulogy Daryl and very informative as well! - I feel now that I actually knew the guy!

Thanks for that. It's pretty hard to compress such a full life into a couple of minutes.

cheers, Daryl.

[WilDun]

Commando cranks used to flex to the extent that the main bearing rollers were running on their end edges, rather than the whole width of the roller. "Superblend" rollers were used to mitigate this - the cranks still flexed, but the bearing lived (longer)

"Superblend"? - Are they also called barrel rollers? - guess they were a bit of a compromise, but they did work.
Had a ride on a "Combat" many years ago - impressive amount of torque!

[Lightbulb]

Interesting reading the Eulogy of Don.
Maryborough is where there is an model plane club flying site where they race the 6.5cc RC pylon racing planes .
Obviously a place of speed and racing in Australia.
Neil

[husaberg]

https://www.youtube.com/watch?v=bQSwD9zvkaE

[pete376403]

"Superblend"? - Are they also called barrel rollers? - guess they were a bit of a compromise, but they did work.
Had a ride on a "Combat" many years ago - impressive amount of torque!

Yes, barrel shaped rollers. more here :http://www.accessnorton.com/what-superblend-t3722.html

[guyhockley]

Plenty of modern "complete" head/barrel examples in the two stroke scene, especially in chainsaws and the like. Not great for buckets though to get the squish clearances right! but then knowing our "bucketeers" they would no doubt, get round that one with head inserts
Manufacturers of powered harnesses for hang gliders almost universally use a kart engine called the Radne Raket, which I think was originally based on a Husqvarna engine with integral head/barrel. There is an upgrade, called the Red Head which involves slicing the top off and replacing it with a detachable head.
http://wind-drifter.com/technical/redheadinstall.php

[Frits Overmars]

Commando cranks used to flex to the extent that the main bearing rollers were running on their end edges, rather than the whole width of the roller. "Superblend" rollers were used to mitigate this - the cranks still flexed, but the bearing lived (longer)All cranks flex. In the case of the Aprilia RSW/RSA engines, crank flexing was allowed through lightly barrel-shaped inner races; the rollers were conventional cylinders.
331860 331861

[WilDun]

Takes me right back to my schooldays when I found two of those Bristol engines (complete radials) in the local scrapyard and I visited them each day on the way home from school - we were not really allowed to go into such places, but I managed to sneak in most days for a while to drool over them (think I might have been about 14-15 at the time).
They were off a crashed Wellington bomber (which had piled into a cliff about 10 miles away during WW2). I was hoping to buy them and take them home, but no cash unfortunately - fortunately?
I hadn't heard of sleeve valves then, but I got as much info on the engines as I could and found out about the unique valves they had - They have intrigued me ever since!

I believe the Napier Sabre aero engine also used sleeve valves (expertise in these was gained through co-operation with Bristol) it had a 24 cylinder 'H' layout, as opposed to a radial and was used in the Typhoon ground attack aircraft). Also I believe Lycoming (Continental?) in the US designed and built a sleeve valve engine which didn't actually go into production.

[Pursang]

All cranks flex. In the case of the Aprilia RSW/RSA engines, crank flexing was allowed through lightly barrel-shaped inner races; the rollers were conventional cylinders.
331860 331861

Some early *onda engines had roller mains in the first models & changed to ball bearings in the subsequent ones.

[Grumph]

Some early *onda engines had roller mains in the first models & changed to ball bearings in the subsequent ones.

Probably cost related - you look at early XL250's and CB450's where they ran rollers direct on the shafts then the later versions with ball mains and soft shafts...the early versions are almost built regardless of cost. While the shafts undoubtedly flex, they're better supported and bigger dia press fits than the British engines. The first 250 Motorsport in particular is almost Manx Norton in the shaft sizing.
They don't tend to do the roller bearings from flex - age eventually sees them go through the hardening on the shafts.

[Lightbulb]

Takes me right back to my schooldays when I found two of those Bristol engines (complete radials) in the local scrapyard and I visited them each day on the way home from school - we were not really allowed to go into such places, but I managed to sneak in most days for a while to drool over them (think I might have been about 14-15 at the time).
They were off a crashed Wellington bomber (which had piled into a cliff about 10 miles away during WW2). I was hoping to buy them and take them home, but no cash unfortunately - fortunately?
I hadn't heard of sleeve valves then, but I got as much info on the engines as I could and found out about the unique valves they had - They have intrigued me ever since!

I believe the Napier Sabre aero engine also used sleeve valves (expertise in these was gained through co-operation with Bristol) it had a 24 cylinder 'H' layout, as opposed to a radial and was used in the Typhoon ground attack aircraft). Also I believe Lycoming (Continental?) in the US designed and built a sleeve valve engine which didn't actually go into production.

Nitriding of the sleeves made the sleeve valve engine a reality. Without it , they seized. The thin wall sleeves work because they are thin, and transfer any heat very quickly to the outer cylinder wall.

[husaberg]

Nitriding of the sleeves made the sleeve valve engine a reality. Without it , they seized. The thin wall sleeves work because they are thin, and transfer any heat very quickly to the outer cylinder wall.

EN10 doesn't need nitriding (on a foul stroke sleeve valve anyway)


Material designation: En 10
Diagram No.: 1311
B.S. designation: En 10
Chemical composition in weight %: 0.62% C, 0.26% Si, 0.69% Mn, 0.026% S, 0.019% P, 0.45% Ni,
0.15% Cr, 0.10% Mo
Steel group: Carbon steels
Applications: No data
Comment: McQuaid Ehn grain size: 5-6 (ASTM), actual as quenched grain size: 6 (ASTM)

[WilDun]

EN10 doesn't need nitriding (on a foul stroke sleeve valve anyway)

Husa,Tell that to Bristol and Napier! :msn-wink:

[husaberg]

Husa,Tell that to Bristol and Napier! :msn-wink:

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

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


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

[WilDun]

I like the article - I had read of another guy (I think around 1950 - can't remember the name who tried racing in IOM) but he moved to Canada and just seemingly faded away. - probably got married to an unbeliever (in bikes).
LM10 Huh? - how come Bristol didn't try it? think they may have used something like nitrided 4140, but not entirely sure.

[husaberg]

I like the article - I had read of another guy (can't remember the name who tried racing on in IOM) but he moved to Canada and just seemingly faded away. - probably got married to an unbeliever (in bikes).
LM10 Huh? - how come Bristol didn't try it? think they may have used nitrided 4140, but not entirely sure.

EN10

it may not have been arround then? but i doubt it it looks like just a plain carbon steel?
or they were looking for a fast cure as it was war time and Rolls Royce were saying their engine was shit.
From what i have read the Bristol herc was improved by a combination of tighter quality, control hand lapping the sleeves, and nitrided steel.
Maybe if the first two were correct the third wasn't needed?

[Lightbulb]

The difference was for the bike engine, it was using an Alloy LM25 outer cylinder with the EN10 sleeve liner, as I read it.
The nitriding was to prevent the steel sleeve from picking up in the steel cylinder for the aero engines.
Flettner may be able to elaborate more on this . I know they tried a lot of combinations until they arrived at the final materials.
Neil

[lohring]

From Ricardo's experiments with two stroke sleeve valves:

331873

Lohring Miller

[Ocean1]

EN10

it may not have been arround then? but i doubt it it looks like just a plain carbon steel?

Looks the same, it's just an absolute bitch to machine.

[Pursang]

There are some very knowledgeable people out there that completely disagree with Me, Frits and Jan about the Ex duct cooling principle.
Roland Holzer in his last iteration of the Modena kart engine made the duct alot shorter, saying that this allowed the pipe ( header,spigot ) to heat up faster
when exiting corners.
Franco at TM has a radical new design in CAD that completely insulates the duct from water cooling with an air gap.
I plan on completely disproving the whole hot duct idea ( or making an idiot of myself ) by very soon having a brand new TM cylinder ceramic coated inside the duct.
This coating surface will be VERY hot where in contact with the retained air/fuel charge.
Doing exactly this process on the Britten made a heap of power, and doubled the water boil time when the bike was warmed up ( as the small rad was ducted correctly
for forward motion,not sitting still ).
It will have only one of two results on the 2T - 125 , instant detonation due to overheated gas being pushed back into the cylinder, or the engine will make more power due to
more heat energy being transferred into the pipe.
Just a very small maybe - would be both effects occur simultaneously. But deto kills engines,so that trumps the other effect every time.
The dyno will not lie,as will the deto sensor on the head.
Even if I am wrong I WILL tell everyone the result,as it has caused some very heated ( pun intended ) discussion, with lots of Italian arm waving in the process.
And of course I would REALLY love to finally prove that The Great Leader was talking out his arse about a hotter duct being better - though he sort of already did that with
his Chinese funded fiasco.

With a bit more than an academic interest in exhaust duct cooling, I'm very interested in the potential value of a ceramic coated duct.

https://s3.amazonaws.com/WEBPOSTS/KIWI+ESE/exhaust+duct+Std.jpg

In my simplistic approach to these things, it looks to me the the only real advantage to extensive water-cooling of the transfer duct is to provide thermal stability.
Thus enabling "careful tuning" to control the point of detonation.

The Negative to this heavy temperature management is removal of heat/energy from the exhaust pulse and the addition of heat to the charge in the duct.
Plus the need to dispose of the captured (& wasted) heat/energy.

As it has been determined, polishing the piston face, allows it to reflect, rather than absorb the heat of combustion.

It follows (to me) that polishing the duct and header pipe should produce a similar result.
Allowing hot exhaust to pass through without depositing heat AND allow cool transfer charge to enter and leave without picking up extra heat (Win-Win?)

Polishing ducts and headers could, perhaps, also be simulated by a process something like this...
.
https://s3.amazonaws.com/WEBPOSTS/KIWI+ESE/jet+hot.JPG

It's smooth & shiny, contains silver and is highly heat reflective.
It is claimed to reduce the external temperature of headers by around 150C. AND that's After heating the steel tube from the inside.
So the heat reflection is internal at the steel to coating junction. Heat reflection without the physical conduction could/should be much higher(?)

(It is possible the inside was coated too, other coating companies suggest that they do it that way)
.
https://s3.amazonaws.com/WEBPOSTS/KIWI+ESE/graphreduction.jpg

Might be just speculation & wishful thinking......or the next Great Step Forward in 2 stroke technology & performance.

This didn't get a single response on ESE, (even though it directly related to a Wobbly post). Not even a derogatory slur.
The ESE Focus is obviously in a different direction at the moment.

Perhaps the Learned Gentlemen that visit here, might have some experience, information, feedback, comment.

cheers, Daryl

[Grumph]

Well I've learned that you don't mirror finish inlet ports as it will actually reduce flow...For max flow, there should be a boundary layer. A finish equivalent to a light hone or bead blasting is sufficient to give the boundary layer something to form on. How this would equate to a high velocity, high temp exhaust which will have a lot of energetic tumbling motion entrapped in it, i really can't guess.
Irving, as always, had something to say about exhaust ports - a thin layer of carbon is a good insulator....

[Lightbulb]

MY take is, how often are you going to re polish this duct? I can't see it staying shiny for very long at all.
Neil

[Ocean1]

Well I've learned that you don't mirror finish inlet ports as it will actually reduce flow...For max flow, there should be a boundary layer. A finish equivalent to a light hone or bead blasting is sufficient to give the boundary layer something to form on. How this would equate to a high velocity, high temp exhaust which will have a lot of energetic tumbling motion entrapped in it, i really can't guess.
Irving, as always, had something to say about exhaust ports - a thin layer of carbon is a good insulator....

I read something years ago about NASA researching what you might call variable texture surface corrugations, trying to match optimum boundary sheer profiles with actual flow velocity.

Sounded far too advanced for any technology I could imagine at the time, but one of the research strings involved dolphins. Their subcutaneous fat ripples as they swim, and the ripples apparently very closely resemble the perfect pitch/texture to minimise drag at any given speed.

There's been at least one elastomeric tube developed in an attempt to mimic that effect.

[Lightbulb]

I don't know about the exhaust surface finish, I have always made the inside of the model engines in the 400 to 600 grit finish range, so quite smooth but not shiny. Anyway's many years ago, a guy in Hamilton a Ferrari that they decided to polish the insides of the inlet ports when they did some work on the heads and valves. It went noticeably worse due to the polish work they did. I am not sure if they got the inlets lightly sand blasted again or not. Somewhere on here at KiwiBiker, was mention of a 400 grit surface finish for inlet ports. Can't remember who said it though.
Neil

[husaberg]

Looks the same, it's just an absolute bitch to machine.
i was meaning from the look of the basic use spec sheet
it has Si and Ni is that what makes it harder to machine or does it tool harden?

I read something years ago about NASA researching what you might call variable texture surface corrugations, trying to match optimum boundary sheer profiles with actual flow velocity.

Sounded far too advanced for any technology I could imagine at the time, but one of the research strings involved dolphins. Their subcutaneous fat ripples as they swim, and the ripples apparently very closely resemble the perfect pitch/texture to minimise drag at any given speed.

There's been at least one elastomeric tube developed in an attempt to mimic that effect.

shark skin as in the swimers togs to replicate a sharks skin.
http://www.symscape.com/blog/swimsuit-banned-as-technology-doping
http://theconversation.com/fast-suits-and-olympic-swimming-a-tale-of-reduced-drag-and-broken-records-7960
Golf balls is another. although a little more complicated.
http://www.aerospaceweb.org/question/aerodynamics/q0215.shtml
I polish exhaust ports on 2ts as i can;t be arsed removing carbon later.

lightly sand blasted again or not. Somewhere on here at KiwiBiker, was mention of a 400 grit surface finish for inlet ports. Can't remember who said it though.
Neil
dremel finish flatted off with 400 git is perfect according to Jan? i think.


From Ricardo's experiments with two stroke sleeve valves:

331873

Lohring Miller
nice find.Ricardo was years ahead of himself even with tapering of ports as well as 4v and squish turbulence too
But in modern terms #The coolant temp should not be allowed to get anyhere near 100C on a competition engine esp a two stroke.

[ken seeber]

Wonder if this goes any better than anything else? Would take a few hours of CNC programming..:sweatdrop


331880

[Grumph]

The only positive story I know about mirror finishing inlet ports relates to the Suzuki GSXR750J. It was supposed to be the ultimate in that family, shorter stroke, bigger valves, bigger ports...
Flowbench and dyno work showed that the inlet ports in the casting were too big. AMA rules said you couldn't add material..
By mirror finishing the inlets a turbulent boundary layer formed. Apparently the mirror finish gives a sort of grip and release effect on air passing which makes for a turbulent layer.
The thick turbulent layer had the effect of reducing the cross sectional area of the port...job done.

That head has become a favourite of the US drag racers for fitting to the old air cooled GSX1100, bolts straight on , just block the oil drains.

[Ocean1]

i was meaning from the look of the basic use spec sheet
it has Si and Ni is that what makes it harder to machine or does it tool harden?


Oh aye. Well it's almost all carbon steel, even mild steel has a bit, just not enough to harden.

Anything with Si is hard on tools, which nowadays usually means carbides, which often means compromising tool profiles. High Ni content steels tend to high sheer strengths, which means they tear easily. Well, not easily, in fact it takes a bit of grunt but it seems to like bonding to the tool surface, so it tears rather than sheering nice and cleanly. So without razor sharp edges, a nice rigid setup and a decent coolant you get jagged finishes, especially screwcutting and similar.

High manganese stuff can be a pain too but my favourite thing to bitch about having to machine is AB2. I took some castings to a local who had a big fuckoff Toss horizontal borer, ('cause I didn't want to spend forever doing the job on my universal). His machine wouldn't think anything of driving an 80mm 6 tip face cutter at 10mm x .5 cuts in 316, but the best he could do on that stuff was 2mm x .2. He's been deeply suspicious of every job I've taken there ever since. :laugh:

[Ocean1]

Wonder if this goes any better than anything else? Would take a few hours of CNC programming..:sweatdrop


331880

I can imagine. Any idea what they used to cut it?

[Pursang]

Well I've learned that you don't mirror finish inlet ports as it will actually reduce flow...For max flow, there should be a boundary layer. A finish equivalent to a light hone or bead blasting is sufficient to give the boundary layer something to form on. How this would equate to a high velocity, high temp exhaust which will have a lot of energetic tumbling motion entrapped in it, i really can't guess.
Irving, as always, had something to say about exhaust ports - a thin layer of carbon is a good insulator....



Not too concerned about flow,at the moment. (Seems like every discussion about this subject, out there, is always about the Flow)

Limiting/minimising heat transfer, into (and out of) the exhaust port walls, is the goal. Whatever works best, be it silver mirrors, refractory ceramic or carbon crust.

Perhaps a little bit of high school Physics.

331883

Of these 3, Forced Convection is the source of our heat energy (in the port & header).

IR Radiation: (Waves not particles:wavey:)

Dull surfaces are good absorbers and emitters of infrared radiation.
Shiny surfaces are poor absorbers and emitters (but they are good reflectors of infrared radiation)

Conclusion: Dull, Matt surfaces are best at taking heat from the exhaust gas AND transferring that heat to the cooler fresh charge.

Conduction: (Fast molecules smashing into Slower molecules :bash:)

A vacuum is the best conductive insulation, no particles to transfer the energy.
Air gap is an alternative. The High Temp surface coatings consist of hollow ceramic nano balls, to provide the air gaps.

Conclusion: A shiny smooth reflective surface finish with insulating ceramic nano balls might be a good way to avoid taking heat from the exhaust gas and NOT transferring that heat to the cooler fresh charge. Maybe???

And this might be why simply a polished surface OR a ceramic coated one are (reportedly) not, on their own, notably effective.
The result of combining the two might be greater than the sum of the parts. (like a Vacuum Flask)

Cheers, Daryl.

[Pursang]

MY take is, how often are you going to re polish this duct? I can't see it staying shiny for very long at all.
Neil

Burn marks (carbon) form where the raw fuel meets a surface that is above its ignition temperature.

That's Exactly what I'm trying to avoid by limiting exhaust heat transfer.

Besides My engine doesn't need to run for hours between pull downs.

Cheers, Daryl.

[husaberg]

The only positive story I know about mirror finishing inlet ports relates to the Suzuki GSXR750J. It was supposed to be the ultimate in that family, shorter stroke, bigger valves, bigger ports...
Flowbench and dyno work showed that the inlet ports in the casting were too big. AMA rules said you couldn't add material..
By mirror finishing the inlets a turbulent boundary layer formed. Apparently the mirror finish gives a sort of grip and release effect on air passing which makes for a turbulent layer.
The thick turbulent layer had the effect of reducing the cross sectional area of the port...job done.

That head has become a favourite of the US drag racers for fitting to the old air cooled GSX1100, bolts straight on , just block the oil drains.

My understanding of that model was it was fine on the road and gave more power then the previous model but when modified and used with longer duration cams then the std road ones the package never worked as good as the old motor did when modified. it was a bridge to far.
Pretty sure the later suzukis sprads with improved heads and tech went back to the same short stroke bore stroke ratio years later with no issues.
Your comment made me think of when Muzzy got pinged one year in the Scott russell/Gobert WSB era for running a device that made the FCR41 into 39mm carbs.
They had got away with it all year, as they designed them to stay attached to the intake manifold this was allowed but one day at tech inspection they came appart with the carbs.
so they had to fidlle them back in.
I think they used them at almost all tracks. likely for the same reason the Suzuki never worked properly.
I think the rules then were std carbs and gearbox and rod material which was why the OWO1 and the ZXR750RR had the CR box and slide carbs and the Ti rods.
That said it must mean the the RC30 won all its races on race kitted CV carbs because thats what they had std so thats pretty impressive in hindsight.

[Lightbulb]

Burn marks (carbon) form where the raw fuel meets a surface that is above its ignition temperature.

That's Exactly what I'm trying to avoid by limiting exhaust heat transfer.

Besides My engine doesn't need to run for hours between pull downs.

Cheers, Daryl.

What I do know is the polished piston crowns and heads only stay polished for like a couple of runs so like 3 mins of running.
Inside the pipes, a new pipe stays clean only for maybe 1 run if that and only if it is never run close to being lean. If it goes lean for just the shortest of time, it turns in colour. The irony for the model engines, it seems that as they build a carbon/ dark something layer inside the pipes, the better they run. Which is the opposite of your object or ideas.

Neil

[Pursang]

What I do know is the polished piston crowns and heads only stay polished for like a couple of runs so like 3 mins of running.
Inside the pipes, a new pipe stays clean only for maybe 1 run if that and only if it is never run close to being lean. If it goes lean for just the shortest of time, it turns in colour. The irony for the model engines, it seems that as they build a carbon/ dark something layer inside the pipes, the better they run. Which is the opposite of your object or ideas.

Neil

3 minutes might be enough.

So many other variables, Fuel & Oil & A/F ratio, ignition timing & exhaust temperatures, warm up, piston & rings & bearing run-in time.

I would really prefer not to fabricate a water-cooled exhaust duct with auxiliaries, if I can find any way around that.

Cheers, Daryl.

[Frits Overmars]

What I do know is the polished piston crowns and heads only stay polished for like a couple of runs so like 3 mins of running. Inside the pipes, a new pipe stays clean only for maybe 1 run if that and only if it is never run close to being lean. If it goes lean for just the shortest of time, it turns in colour. The irony for the model engines, it seems that as they build a carbon/ dark something layer inside the pipes, the better they run.All of the above is true, Neil. But wait, there's more.
Assuming you're talking about your 6,5 cc F3D engines, one should know that they run on too-rich a mixture because otherwise that darn glowplug would ignite too early and cause detonation.
Secondly, they burn methanol. The stoichiometric fuel/air ratio of that stuff is 1 kg of fuel to 6,4 kg of air, and too rich would mean something like 1 kg of methanol for every 5 kg of air, or 200 grams of fuel per kg of air.
Next, the mandatory oil/fuel ratio in F3D-competition is 20% by volume. That is 200 cc of very greasy castor oil to every litre of methanol. And since castor oil and methanol have about the same specific density, we can say that the fuel contains 200 grams of oil per kg methanol.
Bottom line: for every inhaled kg of air that F3D engine consumes ('is smothered in' would be a better description) 40 grams of oil.
That is ten (10 !) times as greasy as the lubrication in the Aprilia RSA! No wonder you have carbon build-up while-u-wait.

[Lightbulb]

Yeah that's all True Frits. When they run lean though, it is amazing how little oil comes out. Like the oil becomes a fuel as well.

With that picture of the golf ball effect inlet tract, it was done using EspritCam 5d cam solutions. Not sure what engine it is though.

Neil

[Pursang]

I would really prefer not to fabricate a water-cooled exhaust duct with auxiliaries, if I can find any way around that.

Methanol & Castor Oil is certainly an option.

I've raced a B33 500 BSA on Methanol and It's amazing how cool they run, compared to petrol. :cool:
So much so that this one had all the head fins broken off, to save weight, way back in the early 60's.

331885

But I'd rather run the Victa in "Fuel" class sometime later on.

Cheers, Daryl.

[husaberg]

All of the above is true, Neil. But wait, there's more.
Assuming you're talking about your 6,5 cc F3D engines, one should know that they run on too-rich a mixture because otherwise that darn glowplug would ignite too early and cause detonation.
Secondly, they burn methanol. The stoichiometric fuel/air ratio of that stuff is 1 kg of fuel to 6,4 kg of air, and too rich would mean something like 1 kg of methanol for every 5 kg of air, or 200 grams of fuel per kg of air.
Next, the mandatory oil/fuel ratio in F3D-competition is 20% by volume. That is 200 cc of very greasy castor oil to every litre of methanol. And since castor oil and methanol have about the same specific density, we can say that the fuel contains 200 grams of oil per kg methanol.
Bottom line: for every inhaled kg of air that F3D engine consumes ('is smothered in' would be a better description) 40 grams of oil.
That is ten (10 !) times as greasy as the lubrication in the Aprilia RSA! No wonder you have carbon build-up while-u-wait.

do they have it that "greasy" because of the nitro fuel, or because they have no rings?
Why would the rules define how much oil to run was it to stop a Belray style no but mines on 300:1 ration pit bragging contest?

[Lightbulb]

The 80/20 fuel came about from the 1960's when engine had Steel liners and cast iron pistons and a plain bronze shaft bearing.
Lower oil contents ,tended to make them wear out prematurely. The Diesel engines, especially in competition would use lower oil content fuels, down to 10% in the early days for a speed advantage and range advantage, but were happy to replace a piston liner set every competition.
The nitro fuel use synthetics if the nitro content exceeded 40% as it does not mix with castor after that.
They never lowered the castor content. But at the level of power now being generated, if the oil level is reduced to even 18%, if they run lean, apart from the glow plug failure, they will pick up and ruin the rod Big end bush and pin.
Neil

[WilDun]

The 80/20 fuel came about from the 1960's when engine had Steel liners and cast iron pistons and a plain bronze shaft bearing.
Lower oil contents ,tended to make them wear out prematurely. The Diesel engines, especially in competition would use lower oil content fuels, down to 10% in the early days for a speed advantage and range advantage, but were happy to replace a piston liner set every competition.
The nitro fuel use synthetics if the nitro content exceeded 40% as it does not mix with castor after that.
They never lowered the castor content. But at the level of power now being generated, if the oil level is reduced to even 18%, if they run lean, apart from the glow plug failure, they will pick up and ruin the rod Big end bush and pin.
Neil

Neil,
So really the model engines don't bear a lot of resemblance to competition engines used in bikes, karts etc. mainly because of the use of ringless pistons and plain bearings (where lubrication is concerned) and where pollution is really of no consequence (at present) and the use of "excess" oil which either comes out raw or as smoke!

What I am interested in and would be keen to understand is, how the ignition event timing is controlled (with either glow or diesel) - is it controlled by compression and what happens as the compression gets lower with wear? - more oil required? Is the compression more dependent on the oil content than with ringed pistons?

Just another (more mundane) thing - I have an OS 45 AX motor (not the Mk.2) which has been sitting a few years partially run in (with standard glo fuel I assume) I have heard that on the odd occasion the plating has been "flaky" on those - how to run it in properly, is what I want to find out!

[Lightbulb]

Neil,
So really the model engines don't bear a lot of resemblance to competition engines used in bikes, karts etc. mainly because of the use of ringless pistons and plain bearings (where lubrication is concerned) and where pollution is really of no consequence (at present) and the use of "excess" oil which either comes out raw or as smoke!

What I am interested in and would be keen to understand is, how the ignition event timing is controlled (with either glow or diesel) - is it controlled by compression and what happens as the compression gets lower with wear? - more oil required? Is the compression more dependent on the oil content than with ringed pistons?

Just another (more mundane) thing - I have an OS 45 AX motor (not the Mk.2) which has been sitting a few years partially run in (with standard glo fuel I assume) I have heard that on the odd occasion the plating has been "flaky" on those - how to run it in properly, is what I want to find out!

Well the modern model engines like the one Frits had involvement with is like a miniature motor bike engine with the full cast jug transfer ports, integral ceramic balls running directly on the crankshaft for the main bearing with an outer shell in the case. With a domed piston and a head to suite. The only thing old fashioned is the 20% castor oil supplied fuel. Being that Castor oil is from plants and is natural, I think that they are actually environmentally friendly, as the methanol and the castor when burnt are making compounds that nature will readily break down anyway over time. But that's another story all together. The ignition timing in the glow plug engine is controlled by the compression ratio to a point, the wire diameter and length(of the glow plug itself) the chemical make up of the platinum wire, and the over all temperature of the cylinder/head. So you can have the head at a certain volume, like in a sport class that does not allow for any compression changes to the engines for example. So on cold days, you run a hot glow plug. A hot glow plug is made when it has either a smaller diameter wire in it and/or a bigger hole in the glow plug body surrounding the helical wire coil. Another way is using what is called a glowbee plug, which utilises a flat coil wire, and comes in different wire diameters, different wire lengths, and different wire alloy mixes. In general, the thin wire plug with a long coil will be a hot plug , while a larger diameter coil wire with a shorter length will be cold plug. So thick wire is like 0.3mm dia or 0.35mm dia, while thin wire is in the 0.12mm dia or 0.15mm dia with 0.2mm dia being a standard wire diameter. With the globee style, if the coil is left laying fairly flat in it's geometry, it will behave like a colder plug, and a lifted coil geometry will behave like a hotter plug.
So with the combination of heat ranges in glowplugs it has about the same effect as raising or lowering the head by as much as 0.07mm or 3 thou with a 6.5 cc engine. On the smaller 2.5 cc engines, the various plug selections like raising or lowering the head by 0.05mm or 2 thou. So from 1 extreme to the other on the 6.5 cc engine, the plugs can give a head setting change equivalent of upto 6 thou and the 2.5cc engine about 4 thou. So they become with the high power output engines more difficult to find the middle sweet spot.
The diesels have a variable compression head, with a small contra piston for raising and lowering the engines compression setting. The diesels are more temperature sensitive than the glow engines, and are also more sensitive on the fuel mixture setting as well. So the cooling of the engine in the model of the diesels is far more critical and so is the loading on the engine more critical at the same time. If the diesel is slightly over loaded, as it is flying through the tank of fuel, it will build heat and after about 34 to 40 laps will be over heated, ie a head temp will exceed 180 deg C. If it is under loaded, it will rev higher, and will keep at the heat setting for the whole run, ie about 165 deg C A too under loaded engine will chill off if it has too much cooling as well, and then will under perform. So then you put on more compression etc to get more heat and it will over heat early . The fuel id very critical on the racing 2,5cc engines and generally the exact formula the teams us is kept quite secret. But in general it will be a kerosene type compound for 50 to 65 %, an ether for 20%to 35%, an oil (usually castor oil 5% and a synthetic combined total 8% to 15%) an ignition improver, Like Diesel cetane improver, Amyl Nitrate, Amy Nitrite, IsoPropyl Nitrate, or a mixture of any of the above ignition improvers in a percentage from 1% to 3%, and sometimes they then add TEL, tetra ethyl lead, or Ferrocene to the fuel mix as well, even though it is a diesel, they add these anti knock additives as well. So you can see that the modern model diesel engine no longer run on the old 1 part kero 1 part castor oil and 1 part ether.
A long post I know, but this gives a basic run down on the state of current model aircraft engines with only a few moving parts. Yes I have made and designed and run variable compression glow plug engine heads as well over the years.
As to your OS engine, just take the back plate off it, and the head off(if you take the head off, do not disturb the rotational position of the liner) and use glow fuel to clean it out and make sure it is not gummed up. Run it with a 9X6 prop, so 9 inch diameter 6 inch pitch APC or what ever you can buy. When you run it up, use full throttle, wind in the needle till it starts to sag, then open the needle from that point 3/4 of a turn.It will be very rich, if it is too rich for take off lean about 1/8 tun at at time. You should be able to pinch the fuel supply line momentarily, and the engine pick up RPM. If it sags, then it is too lean. Then just go fly it. Look at the glow plug. If the body of the bottom of the plug is black after a flight , it is too lean or to over loaded. The glow plug body should look like a new plug. Over time, you can lean in the needle a little bit, but keep an eye on what the colour of the plug is. Over time it will darken of course, so when it gets to a light brown honey colour, clean around not to break the wire, the bottom of the plug with a maroon coloured scothch brite fine pad. Gerrn is too course. Washa nd then keep checking the colour. Over time, the plug will wear out. You will know this, as the mixture will require leaning out to make it run as good as it used to. Then put in a new plug. The plugs for the 45 is a OS #8, or OS #3. The fuel can be from 5% nitro to 15% nitro. It can run on no nitro fuel, but is more difficult to tune day to day. I recommend 10% fuel. After running for the day, let it run out of fuel or pinch off the fuel line, drain the tank, draw air through the fuel line to make the needle area dry of fuel, and then oil with any ATF fluid. Auto transmission fluid. It has buffers for both alkalines and acids.
Neil

[Frits Overmars]

do they have it that "greasy" because of the nitro fuel...The mandatory 80/20 fuel for F3D contains 80 % methanol and 20 % oil - no nitro allowed at all.


What I am interested in and would be keen to understand is, how the ignition event timing is controlled (with either glow or diesel) - is it controlled by compression and what happens as the compression gets lower with wear? - more oil required? Is the compression more dependent on the oil content than with ringed pistons?I have no experience with model diesel engines, but glow plugs are a pain. If and when they ignite, depends on the temperature and mass of the glow plug filament, whether the filament is conceiled in the plug body are hanging free in the combustion space, and on the purity of the fresh charge, its fuel/air ratio, its temperature,
and the compression pressure rather than the compression ratio. Improve one of those factors and ignition will occur earlier in the compression phase.

In practice the ignition timing is controlled via the fuel/air ratio: you turn the fuel needle and play it by ear; experience should tell you when you have found a setting with good power that will likely survive the race without detonation setting in and destroying the filament.

When the plane has completed its ten laps, the fuel line is pinched by a servo in order to stop the engine (there is no throttle valve). Just before it stops, you can hear the revs go up, and because of the propeller it can only do that if the power goes up: a clear indication that is has been running too rich.
The alternative is a borderline setting than may either win you the race or, more likely, won't let you finish because detonation blows the glow plug filament away.

When a model airplane has been unusually fast in a race, it often turns out that most of the filament is gone and only a small part is still present, shifting the ignition timing towards TDC. This is an indication that most engines are running with too much ignition advance.

Spark plug ignition would allow a better timing control and a better mixture. But radio control and the necessary high-energy sparks (because of the abundant oil)
don't go well together, and a normal spark plug would about double the height of the engine.
I've tried miniature spark plugs, meant for low-power four-stroke model engines, but in an F3D engine they were destroyed within seconds.

331892 331893 331895 331894

EDIT: seems that Lightbulb and I have been writing at the same time :D .

[Lightbulb]

Great to have you cover what I missed Frits.
Neil

[WilDun]

Thanks guys, it'll take a few reads to digest that lot! I could sit here all night and tell you some hilarious stories about my "self taught" efforts in (attempted) model aircraft flying ....... but I won't, because i would be permanently banned from every Model Aircraft Club in the country! :facepalm:

[Lightbulb]

Hey Will, the important part is you are having fun.
I can't fly radio models. I just don't have the eye thumb brain control.
I do fly the control line speed models and used to fly the combat F2D if you look for youtube video's
and did for a short while do some F2C team race in the early 80's but only made up the numbers really.
I have however kept up with the small changes in the F2C diesel technologies, and try to keep up with the
F2A and F3D pylon piped engines technologies as well.
The model engines fit my budget, but the materials that we are now playing with costs are about the same or more than
some full sized engines. LOL, but I do get to play with some leading edge stuff at times and that is kind cool.
Neil

[T.W.R]

There's roughly $6k of odd ball engines you'll have never seen nor will see again....seeing model aircraft engines are being banded about :msn-wink:
2nd & 3rd pics are a friends built in the 70s; the 4cyl was a idea for a prototype drone engine and the Harley just a build exercise but looking at it now very very similar to a evo block

[Pursang]

There's roughly $6k of odd ball engines you'll have never seen nor will see again....seeing model aircraft engines are being banded about :msn-wink:
2nd & 3rd pics are a friends built in the 70s; the 4cyl was a idea for a prototype drone engine and the Harley just a build exercise but looking at it now very very similar to a evo block

Is the 4cyl a 2 stroke or a flathead like a vintage Plymouth 4?

cheers, Daryl.

[T.W.R]

Is the 4cyl a 2 stroke or a flathead like a vintage Plymouth 4?

cheers, Daryl.


Just a 2 stroke roughly 15-18cc
The guy that made it just made engines as part of his hobby for model aircraft but actually worked on the team that made the high speed cameras for the U2 spy plane :yes: A good mate of the oldman...they were in S.A.M
I'd have to locate some of the other photos of the other engines but there were numerous layouts....4cyl boxer style etc

[Lightbulb]

Seeing that spark ignition with the advance retard lever, reminded me of a French made model diesel engine, that used an eccentric bushing to raise and lower the centre line of the crankshaft, to alter the engines compression ratio. It also altered the port timing as well. There was another engine that rotated the barrel on a very fine thread, and lifted the whole barrel up and down to add or subtract compression. There are so many variations of model engine made it will be a website on it's own. I don't think you could create any really new engine much these days that has not been tried before but mainly due to machine tools or material choice were not really practical to make as working examples. There are numerous variations of rotary valve engines out there as well. Then there are super charged V12 2stroke engines made by a guy in Cambridge recently for something to do and so on. Even been rotary cam model engines made by a Russian modeller in the 1970's to create a stream lined engine for a scale turbo prop model plane. Not sure if it was a 4 stroke, but thought it was a 2 stroke as well.
Neil

[T.W.R]

Have a close look at the lever on the smaller of the two motors ;) 4" nail
They're both kiwi made motors from the 30s

[lohring]

On model engines again; I race RC model boats. While I have run the glow ignition open fuel classes, my expertise is in the 26 to 36 cc spark ignition, "gasoline" fueled engines. (Gasoline is in quotes because there isn't a standard gasoline, unlike with the fuel classes.) We've tested a wide variety of gasolines as well as nitro/gasoline and nitro/methanol mixtures with mostly spark ignitions. We ran a brief series of tests on a 26 cc engine with glow ignition and nitro/methanol fuel, but the glow plugs we had weren't durable enough. The spark plugs failed with 40% nitro fuel, but ran fine at lower levels. We typically run 60% or more nitro in the glow ignition engines.

These small engines have a lot of piston circumference and clearance for their displacement compared to larger engines. We found a long time ago that more oil meant more power, probably due to better piston sealing. Also the engines are very sensitive to friction. The older engines had two rings so removing one gave an instant power boost.

I should also note that modern radios are very resistant to ignition noise and other forms of interference. However, mechanical control system failures are still common. Moisture damage in receivers and servos, as well as plug disconnects and control system battery failure still happen.

Lohring Miller

[Frits Overmars]

Is the 4cyl a 2 stroke or a flathead?

Just a 2 stroke roughly 15-18ccSure. Hence the valve springs, right?
331914

[guyhockley]

Neil,
So really the model engines don't bear a lot of resemblance to competition engines used in bikes, karts etc. mainly because of the use of ringless pistons and plain bearings (where lubrication is concerned) and where pollution is really of no consequence (at present) and the use of "excess" oil which either comes out raw or as smoke!
Apart from the ringless pistons, sounds a bit like my British Seagull outboard!

[guyhockley]

Kind of sleeve valve and model engines, these were heavily featured in british magazines a few years back.
http://www.rcvengines.com/

[T.W.R]

Sure. Hence the valve springs, right?

:nono: Wrong.....have to blow your theory out there fella :rolleyes: try mock valve springs

[Pursang]

Kind of sleeve valve and model engines, these were heavily featured in british magazines a few years back.
http://www.rcvengines.com/

Probably the best rotary valve concept I've seen..so far!
She'd rev Ok, and the rapid exhaust bleed-down opening would lend itself to a 'tuned' pipe. (4T long expansion chamber).

331917

331921

Would make an 'interesting' 2 Stroke too, with the piston completely separated from the valve function.

Big bore, Short stroke, lots of squish, asymmetric timing.

Exhaust & transfer flows would be upside down.

Think like the piston is the effective head and the RV head is the piston at BDC.

Where to put the spark plug??:scratch:

Cheers, Daryl.

[Frits Overmars]

Just a 2 stroke roughly 15-18cc
331914
Sure. Hence the valve springs, right?
:nono: Wrong.....have to blow your theory out there fella :rolleyes: try mock valve springsWould love to. And the inlet ports at the same height as the exhaust ports would be a mock-up as well?

[T.W.R]

331914Would love to. And the inlet ports at the same height as the exhaust ports would be a mock-up as well?

Your only looking at a picture making assumptions......:oi-grr: so stick to what you think you know :clap:
I've seen the motor in the flesh, held it and heard it running ;)

[Pursang]

Would make an 'interesting' 2 Stroke too, with the piston completely separated from the valve function.

Big bore, Short stroke, lots of squish, asymmetric timing. :scratch:

Cheers, Daryl.

AND Whatever timing profile you might wish for.

331929
331930
and this one...

https://s3.amazonaws.com/WEBPOSTS/KIWI+ESE/nautilus+drive.gif

cheers, Daryl

[WilDun]

Your only looking at a picture making assumptions......:oi-grr: so stick to what you think you know :clap

We sometimes look at things and the signal might suddenly take a wrong turn on the way to the brain! - that's the only conclusion I can come to here!
Although, maybe it could it just be something simple like posting the wrong picture? - or how about not understanding engines - the person to whom I am referring?? - that I refuse to disclose!:rolleyes:

Or is it the start of yet another troll session?

[guyhockley]

Quick, a distraction!
Rotary valves and oil splash bottom ends for 2 smokes, plus a few other interesting bits...
http://www.motorsportmagazine.com/archive/article/december-1962/16/scott-two-stroke-car-engines

[T.W.R]

We sometimes look at things and the signal might suddenly take a wrong turn on the way to the brain! - that's the only conclusion I can come to here!
Although, maybe it could it just be something simple like posting the wrong picture? - or how about not understanding engines - the person to whom I am referring?? - that I refuse to disclose!:rolleyes:

Or is it the start of yet another troll session?

Cute
I'd bet the majority of model aircraft engines you've ever had anything to do with would stupid wee cox engines, maybe if you were lucky 1 or 2 OS engines & possibly a couple DC engines most likely nothing bigger than a Merlin or Sabre
Bet you wouldn't even know how many different model aircraft engines were built by kiwis prior to the 1970s

To see how clued up you are on these do tell what the difference is between an O&R 60 & Purple Head O&R 60 you probably haven't even got a clue what O & R stands for
Or an easy one what a Mills .75 was copied off
Or what a Taipan is & what it's capacity was
Or what S.A.M stands for

[WilDun]

Cute
I'd bet the majority of model aircraft engines you've ever had anything to do with would stupid wee cox engines, maybe if you were lucky 1 or 2 OS engines & possibly a couple DC engines most likely nothing bigger than a Merlin or Sabre
Bet you wouldn't even know how many different model aircraft engines were built by kiwis prior to the 1970s

To see how clued up you are on these do tell what the difference is between an O&R 60 & Purple Head O&R 60 you probably haven't even got a clue what O & R stands for
Or an easy one what a Mills .75 was copied off
Or what a Taipan is & what it's capacity was
Or what S.A.M stands for

Oh well, I'm sure that's important to you and I guess you are most probably absolutely correct - I do fully understand where you are coming from and it's good to know these facts.
But please don't let it become a case of mine's bigger than yours, - no it's not. - yes it is - no it's not, etc etc .......... ok?

BTW, I maybe know the answers to about one third of your questions, and would be interested to hear the others as well, but I could cheat and look them up of course! :yes:

[T.W.R]

Oh well, I'm sure that's important and I guess you are most probably absolutely correct,
As I suspected, it's a case of mine's bigger than yours, - no it's not. - yes it is - no it's not, etc etc .......... bye!

:lol: well you & the other one were questioning what you'd been told just going on a picture without actually having seen, heard, or handled in the flesh then & again now topping it off with sarcasm.
If you can't handle getting called out on what you actually know about the items in question it's best to keep your trap shut and accept what you've been told.
This coming from someone who has over 40yrs of being pretty close to the actual hobby, having also been a member of 2 ChCh model aero clubs, been on a very intimate relationship with who was the owner of the largest collection of model aircraft engines in NZ and a internationally known & respected aero modeller.

[ken seeber]

I've got a deja vu coming on..:tugger:

[WilDun]

I must say I actually do understand your reasoning for saying all this - I'm sorry but life becomes more restricted as we get older and the things we used to do become only memories (as they do for me and it's not funny), but please keep what you say and how you say it in check!

We, on the forum have been here before ........ so get a life and be a good boy ..... bye.

[WilDun]

Quick, a distraction!
Rotary valves and oil splash bottom ends for 2 smokes, plus a few other interesting bits...
http://www.motorsportmagazine.com/archive/article/december-1962/16/scott-two-stroke-car-engines

Guy,
Sorry for the "Old Fella" spat - hopefully it'll blow over - I mean, why did they ever do away with steam anyway and try to introduce these new fangled two strokes in their place? - It'll never work! .............and they still haven't been perfected even to this day! :facepalm: That's why this forum exists, sort of the last hope for sorting out the two stroke engine!

Scott was a genius in his day, but even geniuses sometimes don't make it!

[Pursang]

Guy,
Sorry for the "Old Fella" spat - hopefully it'll blow over - I mean, why did they ever do away with steam anyway and try to introduce these new fangled two strokes in their place? - It'll never work! .............and they still haven't been perfected even to this day! facepalm: That's why this forum exists, sort of the last hope for sorting out the two stroke engine!

Scott was a genius in his day, but even geniuses sometimes don't make it!

Thou shalt not take the name of the lord thy Scott in vain"
(Inventor of the RD250LC, in 1908)

Here was his opinion on the future of two-stroke engines..
331932...(in 1914).

Speaking of 1914 here is his TT race engine for that year. A configuration that is still current, 100 years later.:msn-wink:
331933

The rotary valve, driven by lever arm, previously gear train(1913) & before that chain(1912) controlled inlet flow to the crankcase or direct to the transfers.:eek:

The twin plug head allowed High compression in 2 compact chambers, even with the deflector piston.:2thumbsup

Truly a Giant to attempt to stand on the shoulders of.:not:

cheers, Daryl.

Sorry accreditation Due: Info from http://www.scotttechnicalities.com.au/ lots of good stuff.

[WilDun]

..................The rotary valve, driven by lever arm, previously gear train(1913) & before that chain(1912) controlled inlet flow to the crankcase or direct to the transfers.:eek:
cheers, Daryl.

Daryl, please forgive me for being an absolute nit picking asshole, but ........ oscillating! - not a rotary!

[Pursang]

Daryl, please forgive me for being an absolute nit picking asshole, but ........ oscillating! - not a rotary!

You are Forgiven..you absolute nit picking asshole!

Chain & gear driven ones were rotary, and this one is an ocelot 331934:nya:

Cheers, Daryl.

[Lightbulb]

Cute
I'd bet the majority of model aircraft engines you've ever had anything to do with would stupid wee cox engines, maybe if you were lucky 1 or 2 OS engines & possibly a couple DC engines most likely nothing bigger than a Merlin or Sabre
Bet you wouldn't even know how many different model aircraft engines were built by kiwis prior to the 1970s

To see how clued up you are on these do tell what the difference is between an O&R 60 & Purple Head O&R 60 you probably haven't even got a clue what O & R stands for
Or an easy one what a Mills .75 was copied off
Or what a Taipan is & what it's capacity was
Or what S.A.M stands for

I know who Olsen and Rice are, but not the differences in their engines, way before my time.
Like wise with the Mills series of engines.
I did know Gordon Burford through the phone only and spoke with him numerous times during the early 1980's until the late 90's was my last call to him. Never did get to meet him in person, but he did share alot of his ideas with me.
No idea about S.A.M,
But I do know Harvey Westland, who made engines of his own design and had a performance ahead of it's time . I stayed with Harvey when he used to live on his sheep farm out of ChristChurch. I have one of Harvey's 29 speed engines and pipes, and a spare case that needs refurbishing, and of course a model needs to be made for the 29 speed engine to run it yet again.
Neil Lickfold

[husaberg]

I've got a deja vu coming on..:tugger:

. .331935

[T.W.R]

I know who Olsen and Rice are, but not the differences in their engines, way before my time.
Like wise with the Mills series of engines.
I did know Gordon Burford through the phone only and spoke with him numerous times during the early 1980's until the late 90's was my last call to him. Never did get to meet him in person, but he did share alot of his ideas with me.
No idea about S.A.M,
But I do know Harvey Westland, who made engines of his own design and had a performance ahead of it's time . I stayed with Harvey when he used to live on his sheep farm out of ChristChurch. I have one of Harvey's 29 speed engines and pipes, and a spare case that needs refurbishing, and of course a model needs to be made for the 29 speed engine to run it yet again.
Neil Lickfold

S.A.M is the Society of Antique Modellers

Harvey Westland was a good mate of the old man's. if you know him you'd have heard or met Martin Langlands, Bill Rouse, Ian Henry to name a few ;)
What sort of model you wanting to throw the motor into? still got a shitload of plans here covering everything from R/C, control line, Stunt, A & 1/2A and a pile of Vintage free flight, gliders, indoor minatures for CO2 & jetX motors, rubber free flight, duration etc

The Mills is a Doonside copy

The Purple Head O&R 60 had a raised piston crown & a slightly deeper dished head....basically the performance spec version and pretty rare

Still got a handful of the old mans engines but the majority got swallowed up by guys in the US

[WilDun]

You are Forgiven..you absolute nit picking asshole!

Chain & gear driven ones were rotary, and this one is an ocelot 331934:nya:

Cheers, Daryl.

You sure know how to make a guy feel good about himself :( ..... well, say it ...... "Oscillating" ;)

[WilDun]

S.A.M is the Society of Antique Modellers

The Mills is a Doonside copy



You perhaps need to know that the person you referred to as "the other one" earlier, (Frits Overmars) is ( I believe) responsible for the design of many European competition model aircraft engines and involved with many other two stroke projects.

The Mills is not a Doonside copy - but the Doonside is a (rather good) copy of the Mills and made in Aus.

The Ohlsson & Rice engines have been around for a very long time and most people my age would have known about them - all off the top of my head and no bull - I mean no Google!

Welcome to our thread (after a stormy debut)! :yes:

[Lightbulb]

I will be looking for a 29 Control line speed model. But with 2 lines not monoline.
I have heard of a Doonside Mills, and thought the Doonside was the copy. I did not realise that the Doonside was the original engine.
Neil

[T.W.R]

You perhaps need to know that the person you referred to as "the other one" earlier, (Frits Overmars) is ( I believe) responsible for the design of many European competition model aircraft engines and involved with many other two stroke projects.

The Mills is not a Doonside copy - but the Doonside is a (rather good) copy of the Mills and made in Aus.

The Ohlsson & Rice engines have been around for a very long time and most people my age would have known about them - all off the top of my head.

Welcome to our thread (after a stormy debut)! :yes:

I don't really care who Fritz is, he questioned what he saw & was told it was mock by someone who had actually seen the engine in the flesh etc yet still tried questioning it.

Wrong! the Mills .75 IS a Doonside copy....I could show you written proof if my scanner was working.

Of course O&R have been around a very long time with a hell of a lot of other brands of engine but they're one of the more respected:yes:

Ha your thread :wacko: Glenn was the original poster so if any one can lay claim to owning this thread it's Husaberg...so dial back the arrogance :motu:

[T.W.R]

I will be looking for a 29 Control line speed model. But with 2 lines not monoline.
I have heard of a Doonside Mills, and thought the Doonside was the copy. I did not realise that the Doonside was the original engine.
Neil

Got a few control line speed model plans, a lot of the control line plans are stunt models including a MkV spitfire and a rather cool looking bi-plane

Mills copied the Doonside and extended the shaft etc :msn-wink:

[WilDun]

I will be looking for a 29 Control line speed model. But with 2 lines not monoline.
I have heard of a Doonside Mills, and thought the Doonside was the copy. I did not realise that the Doonside was the original engine.
Neil

Doonside in Australia copied the original British Mills (which was I believe was originally a wartime Swiss design), and made a very good of copy of it too!
I still have an original British Mills .75 tucked away somewhere, - they were great little beginner's engines and much easier to start and tune than the average small diesel of the day because of their unique transfer design producing excellent atomisation of the mixture and good torque - not so fantastic in the high performance department though!

[T.W.R]

Doonside copied the original British Mills (which was I believe was originally a wartime Swiss design). I still have an original British Mills .75 tucked away somewhere, - they were great little beginner's engines and much easier to start and tune than the average small diesel of the day because of their unique transfer design producing excellent atomisation of the mixture and good torque - not so fantastic in the high performance department though!

That's interesting because I've got a copy of Aero Modeller Jan 84 (Britsh Publication) sitting beside me now with a article on "a guide to free flight scale" written by Bill Dennis that talks about the Mills and it's history and suitability for the class

[WilDun]

Ha your thread :wacko: Glenn was the original poster so if any one can lay claim to owning this thread it's Husaberg...so dial back the arrogance :motu:

We both discussed it, Husa got it going and it has gone along sweetly since then, both of us getting along fine until a cantankerous old bastard with a frazzled brain talking like a pre-teenage kid turns up determined to wreck it!

But this does have a familiar ring to it! a smell that will never go away!

He's back folks! JAW, HEMI MAKUTU and now his present name TWR! and there is a certain other person of interest (known to be an associate? - or is it a crony - maybe yet another aka?).

[T.W.R]

We both discussed it, Husa got it going and it has gone along sweetly since then, both of us getting along fine until a cantankerous old bastard with a frazzled brain talking like a pre-teenage kid turns up determined to wreck it!

But this does has a familiar ring to it! a smell that will never go away!

He's back folks! JAW, HEMI MAKUTU and now his present name TWR!

You need to go have a masti to relieve your pent up frustration

[Pursang]

Been some chatter, about the place, on the value or otherwise of exhaust ports that are not dependent on tuned pipes.

Have a close look at this Excelsior board track racer.

331936

Cheers Daryl.

[WilDun]

Not that it really matters, but just to clarify what I said regarding the "Doonside Mills", - just scroll down a bit and you'll get an article on Mills engines.
Maybe we'd better move on!

http://www.modelflyingnz.org/Docs/Interest/Vintage/AVANZ%20News%20No%20143.pdf

[Pursang]

Auxiliary Exhaust ports. Just above BDC

331937

My thoughts... The exhaust ports provide additional Bleed-down and reduce pumping losses on the Exhaust stroke.

(Bet they sounded Awesome too!!!)

On the Inlet side, inertia of the incoming charge will force any Hot, Residual, exhaust gas out of the cylinder around BDC.

Cylinder will be filled with fresh cooled charge for compression & ignition.

This system was also explored in Ford flat-head V8's, for land speed racing, in the early 1950's.

The flathead V8 is Very exhaust limited. 4 cylinders into 3 ports, passing through the block, from inside the V to the outside.
Ducts were restricted and exhaust heated the block & cooling system substantially.

Other options included reversing the flow, with 8 exhausts from inside the V, and 6 inlets from the outside.

Development stopped with the increased availability of 'modern' OHV V-8 engines.

Here are a couple of pics of a reversed flow V8-60 in a midget.
331938331939

cheers, Daryl

[emess]

Here is something a little less vintage, that I posted on the French Pit-Lane forum: http://www.pit-lane.biz/t6246p25-gp125-all-that-you-wanted-to-know-on-aprilia-rsa-125-and-more-by-mr-jan-thiel-and-mr-frits-overmars-part-5
331772
.

Frits, how do you calculate/measure the effective port opening times?

Thanks,
Mick

[Frits Overmars]

Frits, how do you calculate/measure the effective port opening times?It's a good question Mick, and I'd like to oblige, but I'd need a bit more than the 11 words that you used. More like 11 pages...
It depends on how steeply the cylinder pressure falls off after Ex-open, which in turn depends on exhaust gas temperature and pressure, and on the rate at which the blowndown angle.area increases per crank degree. In a shallow port this rate is rather low, so there will be a bigger difference between its geometrical and effective opening points, as opposed to the geometrical and effective values of a wide port.
But angle.areas are only part of the story; another important factor is the flow coefficient of the upper part of the port. This is where the radiused top edge of the Aprilia exhaust port and its turbulence-suppressing duct shape come into play. In short: it's a lot of theoretical and practical work.

[Grumph]

Been some chatter, about the place, on the value or otherwise of exhaust ports that are not dependent on tuned pipes.

Have a close look at this Excelsior board track racer.


The 8 valve Indians often had similar barrel ports as auxiliary exhausts. The old man was around and racing in the days of mile grass tracks here and once told me that when they were fired up it didn't pay to be alongside as you got showered in oil and unburned fuel....








Here are a couple of pics of a reversed flow V8-60 in a midget.

cheers, Daryl

That's a beautiful restoration - much better finished than it would have been originally, LOL.
I look at the length of the inlet tract runners and wonder if preheating before starting is going to be needed to avoid flooding the cylinders with unburned alky...

[guyhockley]

http://www.gasenginemagazine.com/gas-engines/auxiliary-exhaust

[Pursang]

A very clever gentleman named Dennis Jones (obviously No relation) built this around WW2.

331956331957
331958331959
331960

A ban on supercharging in M/C GP, after the war, rendered it obsolete.
(I bet that was discouraging)..Bugger!:thud:

Pics from here:http://http://way2speed.blogspot.com/2013/09/jones-motorcycles.html (http://way2speed.blogspot.com/2013/09/jones-motorcycles.html)

Cheers, Daryl.

[husaberg]

A very clever gentleman named Dennis Jones (obviously No relation) built this around WW2.

331956331957
331958331959
331960

A ban on supercharging in M/C GP, after the war, rendered it obsolete.
(I bet that was discouraging)..Bugger!:thud:

Pics from here:http://http://way2speed.blogspot.com/2013/09/jones-motorcycles.html (http://way2speed.blogspot.com/2013/09/jones-motorcycles.html)

Cheers, Daryl.

He build other fours as well more conventional ones
Pretty sure i have posted some before.

[Pursang]

That's a beautiful restoration - much better finished than it would have been originally, LOL.
I look at the length of the inlet tract runners and wonder if preheating before starting is going to be needed to avoid flooding the cylinders with unburned alky...

So true, most restorations of vintage racing machines are far "Flasher" than they were run, back in the day.

Racing Friday & Saturday nights on tracks 750klm apart, there wasn't much time to do much more than fit new big-end bearings and knock out the worst dents.

331961

Regarding starting with the loooong intakes, they might have used petrol or ether to get it running, before opening the shut-off valve from the pressurised fuel tank??
(Hand pump on the outside of the cowl.)

Cheers, Daryl.

[Pursang]

Pretty sure i have posted some before.

I wouldn't be surprised.... I did try a quick search of this (Oddball) thread before posting it.

Cheers, Daryl

[Pursang]

http://www.gasenginemagazine.com/gas-engines/auxiliary-exhaust

There really is Nothing New out there, is there

Interesting that a major benefit claimed was reducing the work required to open the exhaust valve.... Must be opening the valve at or after BDC?? :zzzz:

I've also seen that claimed to be a significant power drain in exhaust valved Uniflow two-strokes.

Cheers, Daryl.

[Lightbulb]

Would have he been one of the early people to use shaft drive instead of a chain or belt?
Neil

[Grumph]

The primary benefit of the auxilliary barrel exhausts was probably exhaust valve life. Steels around that time were not that good - the silchrome valve came not many years later. Anything which would reduce valve temperature would have helped.

Daryl - a guy I know locally has an early Edmunds/VW which is finished to show condition and gets carefully exercised once a year...Sadly the Kurtis Offy which was also local - and ex Foyt....Has been sold overseas.

[WilDun]

I wouldn't be surprised.... I did try a quick search of this (Oddball) thread before posting it.

Cheers, Daryl

I think Husa may have been referring to the previous thread he started on vintage racers (forget what it's called).

And ....... in answer to your earlier statement :- There really is Nothing New out there, is there

"What has been will be again,
what has been done will be done again;
there is nothing new under the sun."
(a biblical quote I think)

Wot? even the Ryger?

Amen. :innocent:

[husaberg]

I wouldn't be surprised.... I did try a quick search of this (Oddball) thread before posting it.

Cheers, Daryl

I can't be arsed looking but when i trip over the mag i will post it.
From memory it was made out of a Douglas Dragonfly frame an a "MV like" engine made out of Triumph terrier and Tigercub heads and valves modified to DOHC with rockers then remodified to direct tappets out of a Austin maxi by the next owner. it was 19598 so it was home made state of the art really. it also had an albion gearbox.
Pretty sure Dennis Jones was a "retired" toolmaker

here is a pic
331968

here is the 250 single
http://www.vintagebike.co.uk/wp-content/uploads/gallery/othersitom/jones-250cc-710x570.jpg

[EssexNick]

I seem to remember Jones worked for Rolls Royce when he was building his specials, but your probably right.

[husaberg]

I seem to remember Jones worked for Rolls Royce when he was building his specials, but your probably right.

That sounds about right, plenty of other special builders did a well, like the spondon dude.
i'd have to dig it out it was in a classic bike about 1985 or so. Had a Norton on the cover i think.

[EssexNick]

Stupidly, I flogged all my Classic mags about 25 years ago. I'm glad somebody's kept theirs. I still have a bunch of Motorcycle Mechanics from the sixties and seventies, which make for entertaining reading. If I ever get round to getting a scanner I'll try posting them on here.

[husaberg]

Brian Woolley article. Think I've actually driven one of the Daimlers he mentions round a mate's field. They had 2, one was supposed to be unique as it was a pick up! Done by the factory for their own use, so the story went. Don't remember anything special about the engines, it was the pre-select gearbox that took most of my attention.


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

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


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

I never seen you had already posted that lol


Stupidly, I flogged all my Classic mags about 25 years ago. I'm glad somebody's kept theirs. I still have a bunch of Motorcycle Mechanics from the sixties and seventies, which make for entertaining reading. If I ever get round to getting a scanner I'll try posting them on here.

post the plastic engine from about 84.
scanners are cheap just get an all in one printer

[EssexNick]

Nothing as late as 84. I think the most recent is 74 or 75.

[WilDun]

I think I remember that 4 cylinder special with the Triumph Terrier heads and the heading for the article was "Redundancy Four" - I thought it was sometime in the seventies, but I have also flogged off all my old motorcycle mags.
The guy who built it had been made redundant and had done it as cheaply as possible (did a great job!) - I think it was in "Motorcycle" mag.

[guyhockley]

Dennis Jones article

[guyhockley]

Another one (with some antipodean pages!)

[guyhockley]

And another

[husaberg]

Dennis Jones article
Nice....
Youre going to make me dig out the different article i have now:shit:

[Michael Moore]

Here's a couple of shots of a head casting for a Jones single being machined by John Stevenson. This was done in modern times and I think he had a couple of of Jones' bikes for awhile.

cheers,
Michael

[husaberg]

Dennis Jones article

I just clicked i was crossing my recollection of the Jones 4 with the Marsh 4
https://www.real-classic.co.uk/2017/01/24/marsh-5004-a-really-rare-british-racer/

[WilDun]

I just clicked i was crossing my recollection of the Jones 4 with the Marsh 4 https://www.real-classic.co.uk/2017/01/24/marsh-5004-a-really-rare-british-racer/

Yes Husa that was exactly the bike I was talking about! :niceone:

332007332008

[guyhockley]

Bucket Racers cut 250 fours in half, while in Yorkshire...
https://www.youtube.com/watch?v=-0kBJ5cY7Vk
https://www.youtube.com/watch?v=40LNLs3WKM0
https://www.youtube.com/watch?v=m4eVLUjEfV0
https://www.youtube.com/watch?v=L3-z855NPtk

[guyhockley]

Talking of 6s
http://www.motorcycledaily.com/2012/03/the-new-horex-motorcycle-with-vr6-engine-a-technical-analysis/

[WilDun]

Talking of 6s
http://www.motorcycledaily.com/2012/03/the-new-horex-motorcycle-with-vr6-engine-a-technical-analysis/

An excellent road machine concept, expensive maybe, not a racer and very good, but as always, if it's not the fashionable thing to have then it won't succeed.
Unfortunately it's not the people who know the finer details of machinery or are expert riders, who dictate the terms, it's more the short sighted "image" guys with fat wallets looking to buy this year's something or other (anything to attract attention) who actually make or break a company!

.... and, yes of course I'm a silly negative old fool ..... as usual! :rolleyes:

[Frits Overmars]

An excellent road machine concept, expensive maybe, not a racer and very good, but as always, if it's not the fashionable thing to have then it won't succeed. Unfortunately it's not the people who know the finer details of machinery or are expert riders, who dictate the terms, it's more the short sighted "image" guys with fat wallets looking to buy this year's something or other (anything to attract attention) who actually make or break a company! .... and, yes of course I'm a silly negative old fool ..... as usual! :rolleyes:You and me both, mate. You just described the Harley-Davidson philosophy.
Why invest in technical development when all you need is leather saddlebags and a spud-sound (you know that distinctive H-D idle: potato-potato-potato-potato).
Harley even tried to patent their sound, but they didn't succeed, so now most Japanse marques offer 45° V-twins with the same firing order and with tenfold reliability.

Returning to your 'excellent road machine': that narrow-V six-pot Horex is not really my cup of tea. It violates KISS: too heavy, too complicated, terrible piston shape.

[pete376403]

Not oddball but nice anyway https://m.facebook.com/story.php?story_fbid=1682261175140084&id=483609575005256

[ken seeber]

I know it's not HD technology (really meaning the colour of the saddlebags), or anything ever so refined, but this one makes VW's Dieselgate look pretty mild really.<_<

Pretty sure that all these were 4 strokes:

https://www.youtube.com/watch?v=xmIfjmvXp0I