Oddball engines and prototypes

[Frits Overmars]

346652

would this be considered an opposed piston engine?Not yet, I'd say. Which of course raises the question from which included angle it would be. I'd accept 160° . But then you might as well go for the straightforward solution and make it the full 180°.

[WilDun]

346652 would this be considered an opposed piston engine?

That could also be seen as being related to the "split single" with one conrod - (not really the same), but I did say earlier somewhere that it could be looked on as an opposed piston with a 'U' bend, but that layout (although more compact) does produce a somewhat inferior combustion chamber.
It is still uniflow of course, but in my opinion, head design is inferior when compared with the OP, (ie, no cylinder head!).

[Frits Overmars]

That could also be seen as being related to the "split single" with one conrod - (not really the same), but I did say earlier somewhere that it could be looked on as an opposed piston with a 'U' bend, but that layout (although more compact) does produce a somewhat inferior combustion chamber.
It is still uniflow of course, but in my opinion, head design is inferior when compared with the OP, (ie, no cylinder head!).So we have the split single of DKW (and Puch and others) fame, with a dubious big end arrangement, terrible cylinder cooling and a combustion chamber that is a real bottleneck for the flow,
we have the 'folded' single from the pictures on the previous page, which solved the big end issues, enabled better cylinder cooling, and brought a tiny bit of improvement for the flow,
and we have the Opposed Piston single, which is just perfect in all these aspects.

[WilDun]

Another very interesting design - the two stroke supercharged "Wardill" from pre WW2 days, which was apparently successful for a relatively short time - quite notable for its apparent (mechanical) success from the beginning! also with an extremely compact engine, but it was competing with all the other big players of that era and eventually disappeared.

https://cybermotorcycle.com/euro/wikig/Wardill-and-Sons.html

I had remembered it being featured in one of the British mags way back, but forgot about it for over 40 years! - Then, about 4 years ago I enquired about it in a vintage forum, but any information on it seemed to have been lost! - zilch on the net!

However, out of the blue, I finally got a reply from a young Welshman (Mark Wardill) who is the great grandson of one of the two guys who conceived it! - he was trying to find out all about it ..... success at last!

So I gave him as much info and pics as I could muster (not a lot really) and he took it from there....... He has now formed a company building replicas of his great grandfather's machine ...... however at present he is using a Suzuki GN 250 engine! :facepalm:

His ideas are very different to mine - my interest is only in its unique engine - he is most probably interested in building a complete replica - so far he is putting it in production as the "Wardill 4" (with the Suzuki engine) - it does look good, but I am waiting for the day when he gets someone to build him a replica engine as well!

Anyway, point is, it's not a silly engine design, - with a supercharger having an annular piston, it worked well and deserves some consideration! - with modern materials and a few upgraded ideas here and there ..... who knows!

Trouble with the images! (looks like Twitter has got them sown up) - the picture file system on here won't accept those Twitter files!

(Anyway, here is the full link which will hopefully take you there!)

https://www.google.co.nz/search?q=wardill+engine&newwindow=1&sxsrf=ALeKk03rF9ikaBE4lEzgFVVxLy7c-pPVUQ:1596673100860&tbm=isch&source=iu&ictx=1&fir=Cn5dj8igYiD8cM%252CN56rQvnETuAq-M%252C_&vet=1&usg=AI4_-kTPYZPMxr2Zjt2Cg3voZexq-Beq8g&sa=X&ved=2ahUKEwi92v7npoXrAhWJdn0KHcuUC4AQ9QEwAHoECAsQE Q&biw=1093&bih=530#imgrc=2wBuMyje5LV4WM

[ken seeber]

I always remember (but never saw....) the Trojan split single design. Essentially using a one piece forked rod. This had to flex as the dynamic spacing between the two piston pins varied over the crank cycle.

Not too sure, but maybe the inevitable side loading on the pistons to force the "flex" might have, in a way, partially cancelled out the natural con rod angularity side thrust.

https://simanaitissays.com/2015/07/02/trojan-tales-galore/

Frits could probably advise us in the size and length of a suitable expansion chamber....:shit::shit:

[WilDun]

I always remember (but never saw....) the Trojan split single design. Essentially using a one piece forked rod. This had to flex as the dynamic spacing between the two piston pins varied over the crank cycle. .....................

Frits could probably advise us in the size and length of a suitable expansion chamber....:shit::shit:

Ken, It reminds me of a tuning fork! maybe harmonics comes into the design as well! ..... Unfortunately an expansion chamber needs to be flexible too (in the sense of being able to cope with large changes in revs) - so it's pretty bloody rigid!! :msn-wink:

[katinas]

Thanks WilDun, before that, saw this engine only in patent papers and I had no idea from where it comes. Definitely, this engine is more technically valuable than this motorcycle itself. If GN 250 engine found its chassis, "Wardill" engine need far better place, much better than GN 250 chassis.

After WW II, some DKW superchargers began a second life in speed record cars, named Zvezda. Engines was upgraded through years until aprox 1962, in the hands of Peltzer Alexander (1906-1975), Russian engineer, designer, test driver, born into the family of a comedian, Germany's born I.R.Peltzer.

Original DKW UL 350 (charging piston in bottom position, vertical movement) 30,5 hp at 5500 rpm, was used for the first Zvezda-1 in 1946. From some source, it seems that aluminum cockpit was designed by group of engineers from Auto-Union.
The first races with Zvezda-1 was in November 1946, but sadly A. Peltzer caught a bad cold, and as a result of complications after the illness, his legs were taken away.

1947 for second Zvezda -2, they used DKW US 350, type with centrifugal supercharger 42 hp at 6000 rpm.
But from 1948, DKW US type engine was renamed to Π2, Π3 and Π5 (250 cc, 350 cc and 480 cc all square fours) and upgraded until 1960.

Latest versions: 250 cc 57 hp 7200 rpm and 480 cc 98 hp
350cc engine evolution, with rotary compressor ended at nearly 80 hp at 7500 rpm. for the last Zvezda-6. But looks like this was over the limit for double piston head shape, as holed pistons began to appear more and more frequently.

In second and third picture is the first modified DKW US type engine, in third clearly visible DKW cylinder head with smaller cooling pipe as cooling pump was added. Firstly car body was without any ducts, for less drag, so just tank for cooling water was used. But later with higher hp output, radiator was added with duct in cockpit.

[Flettner]

I like the pressure relief blow off valve in the crankcase for accidental crank case combustion, picture 5.

[Pursang]

I like the pressure relief blow off valve in the crankcase for accidental crank case combustion, picture 5.

I thought they were for making farting noises, to let other people know you have changed gear. :bleh:

cheers, Daryl.

[WilDun]

Thanks WilDun, before that, saw this engine only in patent papers and I had no idea from where it comes. Definitely, this engine is more technically valuable than this motorcycle itself. If GN 250 engine found its chassis, "Wardill" engine need far better place, much better than GN 250 chassis.

After WW II, some DKW superchargers began a second life in speed record cars, named Zvezda. Engines was upgraded through years until aprox 1962, in the hands of Peltzer Alexander (1906-1975), Russian engineer, designer, test driver, born into the family of a comedian, Germany's born I.R.Peltzer.............

Nothing 'motorcycle' from Russia was ever heard of in my younger days! - cold war I guess! - except for the 350cc four cylinder Vostok four stroke racer (that may have been fun at home, but although looking quite promising, was withdrawn from the international scene - unfortunately) - sorry for the guys who designed and built it when the plug was pulled - I'm sure they got very little in the way of cash help, ie. if it wasn't an immediate success!
https://silodrome.com/vostok-motorcycles/

The two stroke split single (in this case carried on from the DKW) seems to have stayed alive in Russia for much longer than anywhere else - and in competition! - (That big end arrangement must have have worked ok Frits), the idea would probably have been borrowed originally from radial four stroke aircraft engines, with their master rod and many linked rods - (only one of each in this case).

It looks like suitable asymmetric exhaust port timing (necessary for the supercharger) was provided by having the crankshaft slightly offset from the centre of the bore.

[breezy]

So we have the split single of DKW (and Puch and others) fame, with a dubious big end arrangement, terrible cylinder cooling and a combustion chamber that is a real bottleneck for the flow,
we have the 'folded' single from the pictures on the previous page, which solved the big end issues, enabled better cylinder cooling, and brought a tiny bit of improvement for the flow,
and we have the Opposed Piston single, which is just perfect in all these aspects.

would this opposed set up have a reduction in torque?... as we are now expecting the combusted fuel to push two pistons and associated parts away from each other.is there any floors in this kind of engine?

[katinas]

Early type Vostok S-360 engine, copy of two cylinder 4t Jawa 350 cc, was used for other big project.
In 1963 work began on the creation of a F1 racing car. Engine named GD 1, was based on the Vostok-S-360 racing motorcycle two-cylinder 350 cc engine, 51 hp at 11,000 rpm, from which the following were borrowed: the design of the Hirth-type connecting crankshaft on roller bearings, one-piece connecting rods , heads with two camshafts and 10 mm spark plugs. The valve timing, the shape of the combustion chamber and gas channels were also repeated from Vostok. This helps to save development time.
The design power of the eight-cylinder GD1 engine, which had a working volume of 1500 cc, was 200Hp at 10,500 rpm. Already the first tests at 6000 rpm showed that it develops 162Hp. But its too late, as in 1966 F1 engine rules changed capacity from 1500 cc to 3000 cc and further work on the F 1 machine had to be suspended.
For Hirth's type crankshaft connection, differential type bolts ( two different threads on each side of the bolt) was used.

[WilDun]

Early type Vostok S-360 engine, copy of two cylinder 4t Jawa 350 cc, was used for other big project.....................

For Hirt type crankshaft connection, differential type bolts ( two different threads on each side of the bolt) was used.

Very interesting indeed! I do like Hirth couplings with the differentially threaded retaining bolt, but I am also interested in learning why a Hirth coupling was used on the crankpin! as well?? - the "zig zag" part being right in the middle of the journal?? - of course it would never move from being true as it might have done with the more common pressed up type we use in motorcycles today.
But we need to bear in mind that everything depends on that differentially threaded bolt remaining tight (and not just one in this case!).

I seem to remember that around the same era (or was it way earlier?) BRM built a flat 16 (possibly "H" 16) cylinder engine in their GP car (not a success) but still very interesting and it employed a Hirth Coupling on the crankshaft.

It would seem that there was both a V16 and an H16 tried by BRM - and there was a Hirth coupling employed in one of them, (dunno which) but need to check it all out!

[Frits Overmars]

Very interesting indeed! I do like Hirth couplings with the differentially threaded retaining bolt... I seem to remember that around the same era (or was it way earlier?) BRM built a flat 16 (possibly "H" 16) cylinder engine in their GP car (not a success) Forget BRM, take a look at the Auto Union Grand Prix car, the first mid-engined racing car, designed by (who else?) Ferdinand Porsche. I tried in vain to find pictures of the crankshaft,
but I saw it in Zwickau (otherwise known as Trabant City) where the original Auto Union race cars were built. It was a feast for the eyes and, unlike its later BRM copy, very successful.
https://en.wikipedia.org/wiki/Auto_Union_racing_car
https://www.youtube.com/watch?v=m0aPekqm2Do

(https://www.youtube.com/watch?v=m0aPekqm2Do)

[WilDun]

Forget BRM, take a look at the Auto Union Grand Prix car, the first mid-engined racing car, designed by (who else?) Ferdinand Porsche. I tried in vain to find pictures of the crankshaft,
but I saw it in Zwickau (otherwise known as Trabant City) where the original Auto Union race cars were built. It was a feast for the eyes and, unlike its later BRM copy, very successful.
https://en.wikipedia.org/wiki/Auto_Union_racing_car
https://www.youtube.com/watch?v=m0aPekqm2Do

(https://www.youtube.com/watch?v=m0aPekqm2Do)

Some exciting machinery around! - funny enough I had seen a lot of info on those rear (mid) engined Auto Union cars - nothing was able to come close once they got themselves established on the track! - So I guess the BRM etc were built from ideas 'whisked' out of Germany after the war! - another one was the beautiful (as I see it) "Bristol" car - however, was it was a BMW originally?? - and was it a commercial success?
Anybody know anything about the engine?

346735346733346734

What the hell did they fight for anyway? - they and the English were cousins really! - so much good stuff got lost (some good stuff got invented as well!) - but what a tragedy it all turned out to be for everyone in Europe!

UPDATE : - engine it seems (body maybe Bristol after all!).


Ok - BMW 328 2 litre straight 6 cylinder engine.

Production period 1936 - 1940

No. of cylinders 6

Bore / stroke 66 / 96 mm

Displacement 1971 cc

Maximum power 59 kW (80 bhp) at 5000 rpm

Production period 1939 1940

No. of cylinders 6 6

Bore / stroke 66 / 96 mm 66 / 96 mm

Displacement 1971 cc 1971 cc

Mille Miglia

Maximum power 95 kW (130 bhp)
at 5500 rpm 95 kW (130 bhp)
at 5750 rpm
Top speed 200 km/h (124 mph) 200 km/h (124 mph)

In all, just 464 copies of all BMW 328 versions were produced. Besides the two alloy racing coupes, several independent coachbuilders tried their hand at coupe bodies over the years, some of which were positively attractive. But the fascination of the 328 Roadsters remained unrivalled.
The BMW 328 Roadster was to have a profound influence on international sportscar construction well into the postwar period, with manufacturers such as Veritas, AFM, Frazer Nash, AC, Bristol, Cooper and Arnolt-Bristol profiting from the BMW 328 phenomenon - three magical numbers which will forever symbolize the sporting core of the BMW marque.

[Frits Overmars]

BMW 328 2 litre straight 6 cylinder engine. Production period 1936 - 1940.
In all, just 464 copies of all BMW 328 versions were produced.And then some.
After World War 2 the Russians started dismantling complete German factories and moving them to Russia, but Russian army officers who had grown fond of 'their' BMW 328 cars, decided to keep the BMW factory in the East-German city of Eisenach, where those cars had been built, in operation, so their supply of cars and parts would be secure.
Production kept going on after the war, which rather irritated the BMW hotshots in West-German Munich, who insisted on a change of name. So BMW Eisenach became EMW.
Like the BMW 328 had been for the Russians, the EMW 328 was a popular car with the East-German Police. When production finally stopped, EMW started producing the three-cylinder two-stroke Wartburg car (named after the local Wartburg castle) which became the standard service vehicle of the East-German police.

[katinas]

Thank you Frits, very interesting about BMW/Wartburg. Wartburg engines were used even on sidecars, for road racing.

At the moment I am little bit immers to that period, when German engineers began working in Russia after the war. A lot of interesting article. Add some text and photo. https://airpages.ru/eng/ru/troph3.shtml And two stroke Nomad II magnesium-zirconium alloy crankcase, piston with its stainless steel crown.


"In 1939, Schnürle began work on the Dz 710—a 16-cylinder, liquid-cooled, engine. The original design was a fuel injected, spark ignition engine, but the design was developed into a two-stroke diesel. However, the Dz 710 had trouble with its pistons and ultimately used a bolted steel plate piston crown. In addition, two crankshafts failed due to torsional vibrations."

"Schnürle was very committed to the Dz 710 engine. At the end of World War II, he made it clear to the Army Air Force that he was willing to go to the United States with his engines and continue their research and development. While the Dz 700 and the two Dz 710 engines were taken to the United States, it was not for Schnürle to continue their development. The ultimate disposition of the Dz 710 engines has not been found, but the eight-cylinder Dz 700 radial engine ended up in a private collection in Florida. Around 1998, it was purchased by a private collector in Germany and returned to that country."

"In 1947 the group of former BMW employees headed by Karl Prestel was mainly engaged in developing the 003C engine because of the August deadline. Germany to make turbine blades was the main obstacle. With the switch from German Tinidur to the domestic EI-403 alloy, engine operating time decreased."

"Work on the Jumo 012 that was to become a prototype for a future turboprop engine continued in a most energetic way. I would remind you that, by the autumn of 1946, two of these turbojets had been built in Dessau. In the USSR they were subjected to refinement in order to increase their operating time. Thus, at Brandner` s suggestion, a new combustion chamber was made. This was a combination of the BMW annular combustion chamber and the separate combustion chambers characteristic of the Jumo. To reduce the intensity of internal processes, the rate of compression was lowered from 6 to 4.5. Much effort was expended to observe the turbine blade-mounting angle since a violation of this parameter caused a breakdown of flow; vibrations, and other unpleasant phenomena. But, many difficult questions such as nozzle thermal stratification, blade flow phenomena, reasons for sympathetic oscillation, and so on could not be solved without the use of precision instrumentation, which the plant lacked."

[WilDun]

Looks like the 'cold war' between the Soviet Union and USA could have been caused by bickering over who had the 'best Germans'! :argue:

BTW I used to ride a Suzuki T20 (which I considered then to be fast), but one of those DKW Wartburg cars passed me when I thought I was really moving and blew me into the weeds!
However someone may have "breathed" on it - possibly it was one being developed as a rally car, I dunno! - but quite an embarrassment !

[Frits Overmars]

I used to ride a Suzuki T20 (which I considered then to be fast), but one of those DKW Wartburg cars passed me when I thought I was really moving and blew me into the weeds!
However someone may have "breathed" on it - possibly it was one being developed as a rally car, I dunno! - but quite an embarrassment !
Wasn't me! I used to win races in a rallycross car based on a DKW 1000S two-stroke triple, but I never took it Down Under. And I doubt that it would have been faster than a good Suzuki T20 (by far the most beautiful bike of its era if you ask me).

[katinas]

Very nice TS 20 crankcase, with vertical split and gearbox double fork is very interesting.

Add Zunddap S27 engine photo, from Sd.Kfz. 303 Leichter Ladungsträger Goliath. I am not sure, how intake flow was controlled. In small photo with crankshaft, clearly seen a hole in the center. As carb attached to crankcase and there is no disc valves, looks like intake flow goes through the crankshaft center shaft like on some RC engines. Or maybe this is piston ported intake, just tunnel goes up and then separated to both cylinders from sides.
https://www.youtube.com/watch?v=hXG7RQTKlBI

[WilDun]

Wasn't me! I used to win races in a rallycross car based on a DKW 1000S two-stroke triple, but I never took it Down Under. And I doubt that it would have been faster than a good Suzuki T20 (by far the most beautiful bike of its era if you ask me).

Yes I loved my T20 on which I was capable of beating the big Beezas and Triumphs on our short street circuits - but to be honest you had to be brave to ride it with its interesting handling characteristics - (bendy banana frame made it wallow somewhat in the corners, spindly front forks which locked up when you braked hard, (at least till the front drum brake started to fade later on, in fact became non existent!) - but I loved it and it went like the clappers and all with a very unsophisticated uncomplicated two stroke engine! and yes, a pleasant looking bike!

I would have loved to have had one of those DKW cars though!

KATINAS
Yes an interesting engine for sure - but I would have preferred just to look at the engine, rather than go anywhere near that "contraption"

[190mech]

katinas,thank you for posting the interesting info on various aircraft engine types from Russia and Germany!So many complicated reciprocating engine designs at the wars end only to be trampled under by the gas turbine engines..

[WilDun]

Yes there was a lot of very interesting stuff in your posts! :niceone:

BTW - Was it you who checked out and researched the "Ryger" stuff (quite a while ago) ?

[katinas]

Yes WilDun, last tests was ended with destroyed piston, because someone call at the moment when I prepare new ring for new test. So after call end, I simply forget to adjust piston ring gap. Very funny.
This year tests with Ryger like piston type shape on normal engine, together with direct intake to transfers, showed the possible cause of zero torque at midrange, before pipe is on, on the Rygerised engine. And surprisingly, this is maybe not because of reduced piston pumping capability, as I tough before.
Perhaps it would be interesting to discuss this a bit and maybe try it again.

Photos of the latest Rygerised version with Honda CR 125 cylinder.

[WilDun]

................ This year tests with Ryger like piston type shape on normal engine, together with direct intake to transfers...............Perhaps it would be interesting to discuss this a bit and maybe try it again.

Photos of the latest Rygerised version with Honda CR 125 cylinder.

Good to see you hadn't given up completely when the huge "Ryger Debate" stopped! - I did not pay much attention to the Ryger at the time because it was really getting out of hand, so I don't know a lot about it! (much of it was "over my head" anyway!) - but I did look in sometimes and the arguments there were pretty bad!
There were so many uninformed opinions which I would probably have added to! (as I said a few posts back I'm just a layman in this area) - the guy who started it all was arguing with everybody in reach - I did feel sorry for him however, in that he was seeing his brainchild going down the tubes!

I actually (me!!) asked him to stop arguing (for the sake of the thread) and making claims he couldn't back up - he said he would, but less than a week later he was at it again.
Obviously I wasn't a very good referee!! ...... so I didn't continue down that path!

I still felt a little sorry his dream led to nowhere though - but in saying that, I didn't really know him or what he was like! - others here did!

But yes, info on your experiments would make interesting reading here if you wish to share!

[Flettner]

Ryger, peer review didn't go so well for them. If you make such claims you need to be prepared to defend them, with actual reality. It didn't stand up to scrutiny very well.
But all was not lost, it created a lot of discussions and idea brainstorming, like I haven't seen in a while, or since. I would like to think progress came from the Ryger sarger. I know it made me 'think'.

[katinas]

........ experiments would make interesting reading here if you wish to share!

Yes of course, just later after this weekend’s Austria 2, as I must focus on my commenting work.

Add Bernard Hooper patent for one cylinder stepped piston engine. Maybe not for very high output, but another “closed crankcase” type, without any additional external moving parts, just piston is opposite to Ryger.

[katinas]

....... I would like to think progress came from the Ryger sarger. I know it made me 'think'.

Two stroke land Holland, summer of 1945.......

[WilDun]

Two stroke land Holland, summer of 1945.......

No,no, - that's a 2017 symbolic monument to a certain failed project - (the R***r)!

I hope that you can learn from the past and manage to raise the (V2?) to greater heights! :niceone:

[katinas]

This photo is unbelievable. And what these two young heads thought in the green meadow……

Sometimes fighters pilots tried change flight path of V1 with a light touch of the wing.

[WilDun]

This photo is unbelievable. And what these two young heads thought in the green meadow……

Sometimes fighters pilots tried change flight path of V1 with a light touch of the wing.

Hawker Tempest/Fury, Meteor (I think) and maybe later Spitfires could do that - I think the one shown there must have been a 'test piece' otherwise it would have destroyed itself (and everything around it)! - but they did a lot of damage to London!

[Frits Overmars]

Two stroke land Holland, summer of 1945...."Umm ... there is a V1 in the backyard..."There was a V1 launch site 4 km from my birthplace, and a stray V2 made a hole in the ground 7 km from my birthplace. Luckily I wasn't yet around at the time; otherwise I would probably have gone and take a look at that hole, and died together with the 20-odd people who did, when twenty minutes after the impact the V2 timing device decided that it should have reached London by then, and went boom.

[katinas]

Frits thanks very much, when I found this previous photo the first thought was about you. But sometimes, only 1 percent of save can defeat 99 percent of the inevitable tragedy like with this unexploded V2 or Austria 1 race or how the arrested miner Dmitry, yesterday managed to escape from a Belarusian KGB/Nazi prison through a very narrow ventilation window and now he is save in Ukraine.
The V2s were first fired on London, but after the liberation of Belgium, the Germans targeted Antwerp. A few were fired on Paris and other French cities. This one fell on Rheims, but didnt explode

[WilDun]

I'm wondering, how come that one is still so intact? - (even if it didn't explode).
Frankly I wouldn't have gone anywhere near the thing knowing just what they were capable of!!

I think that some were shot down just after they were launched - the only time they could possibly be shot down by an aircraft!

I think that there is a lesson here too for the two stroke engine - these things were versatile (like the two stroke) and they, c/w designer found their niche in space travel).

The two stroke engine would be excellent if used as a powerplant for just about anything (as well as drones etc etc) :rolleyes: ...... but even more so when combined with a generator, it could provide simple, economical lightweight and useable power through electric motors for transmission (maybe even 'Ryger type' layout) ..... especially in places where power from an electrical grid is not available or unreliable (not all markets are in 'first world' countries!). - all better and much safer (environmentally speaking) than having power supplied by a crappy surplus nuclear power station bought on the cheap?

........ it could even be used in motorcycles! :laugh:

[husaberg]

oddballs galore
http://www.douglas-self.com/MUSEUM/POWER/unusualICeng/RotaryValveIC/RotaryValveIC.htm

[Frits Overmars]

The V2s were first fired on London, but after the liberation of Belgium, the Germans targeted Antwerp. A few were fired on Paris and other French cities. This one fell on Rheims, but didnt explode
I'm wondering, how come that one is still so intact? - (even if it didn't explode).I wonder too, as the V2 used to descend doing Mach 8; nothing anybody could do about it. So I have my doubts about the obvious soft landing in Reims.


The two stroke engine would be excellent if used as a powerplant for just about anythingEven as a powerplant for powerplants. Ever wondered how the engines of world's first jet fighter, the Messerschmitt ME262, were started? Each jet engine had a small twin-cylinder two-stroke boxer hidden behind its nose cone.

[jbiplane]

The two stroke engine would be excellent if used as a powerplant for just about anything
https://www.foxtechfpv.com/foxtech-nova-2400-generator.html
I am going to make something very similar but lighter and more fuel efficient with fuel injection

[WilDun]

https://www.foxtechfpv.com/foxtech-nova-2400-generator.html
I am going to make something very similar but lighter and more fuel efficient with fuel injection

Keep up your enthusiasm - (have not yet read your link though) - hopefully we'll all eventually come to agree on a common purpose and be able to save the two stroke!
UPDATE - Yes, that would be a basic example of my idea (actually it looks like a good idea!) but that would only be one example (of many) of how to use a two stroke! ..... except that if I were going to produce something to show to prospective clients I wouldn't have gone out on to the street and grabbed the first person I could find and told him to come in and weld everything up for me! - never mind, chrome can hide a multitude of sins!!


.................. Even as a powerplant for powerplants. Ever wondered how the engines of world's first jet fighter, the Messerschmitt ME262, were started? Each jet engine had a small twin-cylinder two-stroke boxer hidden behind its nose cone.

That's it! we are not going to let the two stroke die out! - it is not only indispensable, it is man's and the planet's best friend! ....... but we still have to look after it and upgrade it to satisfy today's needs! ..... or it's gone!
So, to my way of thinking, the electric motor could be seen as either a friend or enemy (of the two stroke! ) - I prefer to see the two stroke controlling the electric motor, rather than the reverse!

[ken seeber]

https://www.foxtechfpv.com/foxtech-nova-2400-generator.html
I am going to make something very similar but lighter and more fuel efficient with fuel injection

JB, the 4.2 kg weight is impressive, but the fuel consumption of 800 gm/kWhr isn't, I would be aiming at 400. Obviously it is based on some existing hand held engine, all high pressure die cast parts I would guess.

Maybe we'll see you in the Foundry section doing some magnesium casting. :facepalm:

[WilDun]

JB, the 4.2 kg weight is impressive, but the fuel consumption of 800 gm/kWhr isn't, I would be aiming at 400. Obviously it is based on some existing hand held engine, all high pressure die cast parts I would guess.

Maybe we'll see you in the Foundry section doing some magnesium casting. :facepalm:

Obviously that guy has been listening to my ideas :rolleyes: - he got it wrong however ..... (I said "inexpensive and simple'"- but he thought that meant 'crap'!)
and it still uses the old style two stroke with all the inherent downsides and problems - never mind, - nice paint job! :laugh:

I think his basic concept is fine though!

[katinas]

I wonder too about V2, but sometimes its happen.
https://www.dailymail.co.uk/news/article-2122370/They-V2-Pensioner-told-police-saw-Hitlers-rocket-drop-sea-vindicated-warhead-intact-mudfield.html

[WilDun]

(BTW An English guy told me this!) - ie that a typical English reaction to something big happening in the area is ....... "just ignore it and perhaps it'll go away!" - they've ignored this for quite a while! :msn-wink:

[katinas]

Again two stroke, this time in ME262. Thanks Frits, very interesting.

https://www.youtube.com/watch?v=BGUqV0dl9gA

https://www.youtube.com/watch?v=xz25KDRE9F4

[Frits Overmars]

I wonder too about V2, but sometimes its happen.
https://www.dailymail.co.uk/news/article-2122370/They-V2-Pensioner-told-police-saw-Hitlers-rocket-drop-sea-vindicated-warhead-intact-mudfield.html
Yep, that's the engine, so the complete beast is upside down in the mud. Must have been a 'soft' landing, compared to the V2's usual behaviour.
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[katinas]

More about ME 262 two stroke RBA/S10 starter. 270 cc 70 mm bore x 35 mm stroke 10.5 hp, 16.5 kg.

[Bonez]

This photo is unbelievable. And what these two young heads thought in the green meadow……

Sometimes fighters pilots tried change flight path of V1 with a light touch of the wing.Quite a few succeeded and there is B&W footage of it being done. It really pissed Herr Hitler off.

The affect of the V1 was more psychological. Hearing the V1 pulse jet fly over, stopping and had no idea where it was going to impact.

That V2 in katinas pic is too tidy for it ever to have ever flown. I was an armourer in a previous life..

[WilDun]

I like how that very compact little starter engine in the Junkers jet engine was used to spool up the compressor! - definitely no room for expansion chambers there!

Sorry, but that's why I keep going on about getting rid of the chamber and maybe replace it with a much more compact inexpensive little turbo! (not saying that I know a lot about that you understand - just what I've been hearing lately).

[WilDun]

Quite a few succeeded and there is B&W footage of it being done. It really pissed Herr Hitler off.

The affect of the V1 was more psychological. Hearing the V1 pulse jet fly over, stopping and had no idea where it was going to impact.

That V2 in katinas pic is too tidy for it ever to have ever flown. I was an armourer in a previous life..

Just thinking, I was actually alive in those days! - time flies! - the V2 was a fearsome weapon and untouchable!
Luckily remote control systems were not quite as advanced!!

[katinas]

Around 20 May 1944, a relatively undamaged V-2 rocket fell on the swampy bank of the Bug River near the village of Sarnaki, south of Siemiatycze, and local Poles managed to hide it before Germans arrived. The rocket was then dismantled and smuggled across Poland.
But yes, that Reims V2 maybe never flow and just little possibility of being pulled from the Vesle.

V-2 rocket being recovered from the Bug River near Sarnaki, about 129 km (80 mi) east of Warsaw

[katinas]

A little reflection, may be related to the Rygerised engine. Not about max power, just about very low Rygerised Honda NS engine torque at mid range, same with two different type of cylinders and different pistons shapes.

Add simplified different schemes, that was tested with pure intake through transfers, without any accommodation from crankcase pressure at BDC, just fluctuations through transfers. The engine response to different schemes has nothing to do with what I expected. Such a huge change, unbelievable.

The first thought about 1 type results, led me straight to 4 type of my NS Ryger's attempt three years ago, when there was very difficult to get out from nearly zero torque between 4000-8000 rpm. So similar engine response.

On Rygerised engine 4 type, transfers ports are connected with under piston pressure at BDC and this is why it was still possible to jump over zero torque interval, unlike with even stronger pulse of 1 type on normal engine, with special piston.
If that’s the answer, maybe worth testing with stepped piston

The published homologated Ryger scheme intake, is very similar, direct to transfers and partly to center, so I can guess that they had a bad mid range torque. But I know nothing about the original Ryger prototype which may be different.
Add red color, on Ryger engine photo, this was simplified example how just deeper pocket in the plate can revert 1 type to 2 type.

In Jbiplane design nice bottom pockets, say like for 2 type, but sadly he must use std cylinders, without big side intake boyesen tunnels, just normal center intake window . So it was impossible for him to extract real advantage of piston configuration, that helps charge engine directly through transfers ports, via crank space.

[WilDun]

A little reflection, may be related to the Rygerised engine. Not about max power, ........................


! am not familiar with the Ryger (didn't pay much attention when all the controversy was on!).
What I would like to find is a link with some explanation on exactly how it works! (sort of "Ryger For Dummies") :msn-wink:

[husaberg]

! am not familiar with the Ryger (didn't pay much attention when all the controversy was on!).
What I would like to find is a link with some explanation on exactly how it works! (sort of "Ryger For Dummies") :msn-wink:

The Ryger effect is a process in which large amounts of money are transformed into over-hyped smoke and mirrors, gag orders and condescending insults to anyone who questions the validly in anyway of a secret design that alledgdly makes 1.5 times the power of the most powerfull engine 70Hp for a 125 and revs to 30,000rpm

[WilDun]

The Ryger effect is a process in which large amounts of money are transformed into over-hyped smoke and mirrors, gag orders and condescending insults to anyone you questions the validly in anyway.

ok, I guess I shouldn't bother then? - Reminds me of our own Rick Maine when he fleeced the Aussies in the saga of his 'revolutionary engine'!- remember him in the early nineties?

[husaberg]

ok, I guess I shouldn't bother then? - Reminds me of our own Rick Maine when he fleeced the Aussies in the saga of his 'revolutionary engine'!- remember him in the early nineties?

Sorry Will i was being flippant.
Katinas is doing some interesting stuff with his own version

[WilDun]

Sorry Will i was being flippant.
Katinas is doing some interesting stuff with his own version

Being Flippant - that's a concept I understand very well! - Guess I'm a combination of both really!
I believe that Flippancy, Bullshit, Blarney, Sarcasm etc. - (call it what you will) is a very necessary part of life as well! ...... If you can't be flippant now and then, what's the point of living? :laugh:

Yes Katinas seems to have done a lot toward exploring the Ryger thing! - not that I had ever tried to understand it at the time!

[katinas]

WilDun, there has been a lot of talk about Ryger and maybe a bit boring to hear again, but for me really interesting again if new intake configuration could help to rise low torque at mid range.
The mechanical side of the stepped piston engine design, may have been tested in various forms in the past, but maybe just “Ryger” noticed that with stepped piston configuration it is possible to arrange intake directly through transfers for charge engine. And this is biggest difference from normal scavenging engine, not stepped piston itself. With stepped piston it is just a matter of self-determination which option will choose, normal or directly to transfers.

Can’t talk about max power, because I didn’t know anything about all other things of original Ryger.
With many mistakes on my previous Rygerised NS engine, zero torque at midrange was the biggest downside, not max power, that was somewhere at 30 hp.

In general, due to the con rod small end width / strength, it is very difficult to construct a narrow bottom part of the piston with a diameter of less than 35 mm.
It can be said, that for engines smaller than 100 cc, the only way is to keep a larger piston diameter / difference between the top and bottom, go oversquare.
So its amazing how Aalt Toersent found space for con rod small end on his Rygerised 50 cc.( add photo with red mark showing possibility of extended transfers pockets ).
In other words, more cc, more space for small end and pin. And the area ratio between the upper and lower parts of the piston could be progressively increased while maintaining the required con rod small end strength for bigger piston engines.

Stepped piston lower part take away some working cc from upper piston. In my case with upper 57mm and lower 38mm, stroke 50.6mm, pumping capacity lowered from 129cc to 71,7cc, (Ryger homologated upper 54 mm, lower 36 mm, stroke 54 mm pumping capacity lowered from 125 cc to 68,6 cc)

Add photos that was posted some time ago.

[katinas]

A real pleasure to read this, after so many years. https://www.pressreader.com/uk/classic-racer/20191217/281565177631393 Tomm Herron just two days before......

I was twelve at the time and after watching the movie, five times, all the school’s math and literature notebooks became catalog of Silver Dream parts, especially the rectangular tachometer…..

Now I think, thanks to Freeman’s poor character, barely put an end to the end, is the reason why Soviet censorship allowed this film to be shown here at the time in 1980.

[WilDun]

WilDun, there has been a lot of talk about Ryger and maybe a bit boring to hear again, but for me really interesting again if new intake configuration could help to rise low torque at mid range.
.................................................. ..........................
Add photos that was posted some time ago.

Thanks, - I dunno why I didn't try to sort it all out in my mind before, but now it's all slowly starting to filter through! - guess there was so much confusion and contradiction at the time and I didn't bother!

[katinas]

Jak-15 with ME 262 engine.
Sound of two stroke RBA/S10 starter from 21.30 to 21.54. https://www.youtube.com/watch?v=LSfmMYsztAw&t=1423s

Again DKW, this time ZW 500 and ZW 600 "Inside the Panzer IV Ausf. A, an auxiliary DKW gasoline engine was provided to power the electric engine that was used to traverse the turret. A round fuel supply opening for the DKW engine, was placed on the rear left of the superstructure roof."

This engine was driving the Leonard-type electricity generator.

Auto Union, DKW-Motor, Typ ZW 500
Type Water cooled
Cylinders 2
Bore and stroke 68.0 x 68.5 mm
Displacement 498 cc
Compression 5.8:1
Max. governed speed 2800 rpm
Net h.p. 12
Length 560 mm
Width 340 mm
Height 510 mm
Weight 60 kg

[WilDun]

WilDun, there has been a lot of talk about Ryger ........................
for me really interesting again if new intake configuration could help to rise low torque at mid range.
.................................................. .......

In general, due to the con rod small end width / strength, it is very difficult to construct a narrow bottom part of the piston with a diameter of less than 35 mm. .................................................. ..........

In other words, more cc, more space for small end and pin. And the area ratio between the upper and lower parts of the piston could be progressively increased while maintaining the required con rod small end strength for bigger piston engines.

Stepped piston lower part take away some working cc from upper piston. In my case with upper 57mm and lower 38mm, stroke 50.6mm, pumping capacity lowered from 129cc to 71,7cc, (Ryger homologated upper 54 mm, lower 36 mm, stroke 54 mm pumping capacity lowered from 125 cc to 68,6 cc)


KATINAS,
In the photos of your "Ryger" type engine (which I seem to have lost), the 'crosshead?/gudgeon pin holder'? appears to be retained by being threaded into the narrow part of the piston?
Am I correct?

[husaberg]

KATINAS,
In the photos of your "Ryger" type engine (which I seem to have lost), the 'crosshead?/gudgeon pin holder'? appears to be retained by being threaded into the narrow part of the piston?
Am I correct?

Will to see any picture a user has posted click on their user name and view attachments by user
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[katinas]

WilDun, alloy part with piston pin is threaded into the steel tube. Tube wall thickness 1.3 mm.
All this complicated piston construction, with small fixing bolt inside, is designed only to make engine as compact as possible, but at the same time maintaining a longer thrust for smaller piston part at TDC (28 mm in my case ) and not to let piston pin hole to clash with lower cylinder seal as masked gudgeon pin is higher than seal at TDC.
So with 50.6 mm stroke, the minimum height of additional plate under the cylinder, that I could do, was 20 mm.
But after every test threaded part little lose, so it s not a good solution. Maybe longer height of that threaded small part could help, but fixing still needed.
Perhaps better chose solid piston with thin steel liner (I even already have it made from a tractor piston pin 38 mm dia. x 0.9 mm thick) and open hole for piston pin from one side, with normal circlip. Of course this add another 8-10 mm to plate so cylinder must be rise from 20 mm to 30 mm.
On Ryger pistons they use special key for pin from one side, but they still must use two bolts to fix it. Narrower part of Ryger piston was coated.

[WilDun]

WilDun, alloy part with piston pin is threaded into the steel tube. ..................

On Ryger pistons they use special key for pin from one side, but they still must use two bolts to fix it. Narrower part of Ryger piston was coated.

Tapered thread? ..... or threads with slightly different pitch?

...............................................

Thanks HUSA, - why the hell didn't I think of that??

[katinas]

The biggest downside of threaded joint, is that after two or three heat cycles, thread tightening between steel and aluminium changed, but piston exhaust side skirt must be fixed always at the same position. Higher accurate could be with bigger thread pitch, but this add more weight and less space.
But yes, tapered thread with side fixing screw, could be a good option without too much complications and helps to save 10 mm in height. Thanks WilDun.

Not in theme. I hadn’t been interested in things like torpedoes at all before, but I found this. Four con rods on one crank pin.
And good example of scaled "Rounded piston theme" with sharp edge at C, although the purpose is different

https://hmvf.co.uk/topic/39632-8-cylinder-torpedo-engine-restoration/

[WilDun]

The biggest downside of threaded joint, is that after two or three heat cycles, thread tightening between steel and aluminium changed,.......................................... .................................................. ........

I was thinking since I suggested that as a solution - when a taper is used in that situation it may tend to expand the tube and maybe not such a good idea after all .......I do still believe that two very slightly different thread pitches might work ( so long as they could be made to lock up at exactly the right place!).

Torpedo motors look very interesting too, (even though I don't know exactly how they work!). I believe the Germans made a very tidy little V8 fourstroke engine for their torpedoes (I may find a pic later) - pity it was made to be blown up! -

Who wants wars? - but then all leaders want to be great (and at the expense of others!). - the military men want to play with their new weapons even if it means sacrificing beautiful engines !!

[katinas]

This is V8 Junkers Jumo K8 engine with head disc valves. PDF format in first post https://ww2aircraft.net/forum/threads/junkers-km8-torpedo-engine.7556/

Yes WillDun, passenger liners Goya, Steuben and Wilhelm Gustloff, mostly with civilian refugees on board, one of the most terrible attack that soviets done with five or six torpedos at the nearly end of War. 20 000 deaths.
And nothing changed, they will do the same now in Belarus with own people, just now days internet not let them go too far.

In 1940 Stalin had all the latest German military equipment. Hitler gave away to soviets a few of the latest planes, tanks, ships (torpedo) for testing and for study, as Stalin abandoned some of the territories that were included in the Ribbentrop Molotov Pact.

[WilDun]

This is V8 Junkers Jumo K8 engine with head disc valves. PDF format in first post .................................................. ..................................
In 1940 Stalin had all the latest German military equipment. Hitler gave away to soviets a few of the latest planes, tanks, ships (torpedo) for testing and for study, as Stalin abandoned some of the territories that were included in the Ribbentrop Molotov Pact.

Yes that V8 is the one I was meaning - very interesting!

War to me is obscene and the only interest I have in it came from the fact that I was born in the last years of WW2 (I must admit I do find the technology fascinating though, especially the aircraft stuff),
So I was more or less interested by things like two Bristol (sleeve valve??) radial engines from a crashed wartime Wellington bomber which had been hanging from a high cliff for years and was eventually taken down and sent to the local scrapyard, which I visited regularly (on the way home from school, around 1957) - just to check that they were ok!. - but eventually they were taken away and no doubt got melted down, just like all the rest of the precious wartime machinery! :rolleyes:

[katinas]

Engine reaction to horizontal exhaust divider. Slightly stronger until 6000 rpm, but when engine is on the pipe, from 9000 rpm power is noticeably reduced. Tried 3 times directly on the road as it only takes a few minutes for changes.
Idea was to see how engine reacts to first part of exhaust opening with compact ex port , but of course is confrontation with returning process as separated lower exhaust part is closed as mix still returned.

[WilDun]

My old mate in Aussie found this photo on the net and sent it to me a couple of days ago (I think that it might actually have been the only photo ever taken of it!). - never thought I'd ever see it again! - dunno who took the photo though, but it was quite good! - thought that I'd send it in anyway just to prove that I'm not ALL talk! :msn-wink:

The guy (on board) got me to design and build a frame and somehow install 2X (co joined) Ariel Arrow engines in it just for an experiment.
The bottom engine was original and the top one had the gearbox sawn off and I made an adaptor to take the rest - The frame was made to accept a Triumph front end and he did all the other stuff ( technically it was his bike).
We got it going quite well (with quite a few problems to overcome) but we did get it going - not too badly! ...... this, I think was around 1969 - 70?

Sorry about the rusty pipes - it was sitting around in a shed for a couple of months prior to this!

Photo was taken at Bay Park (Mt Maunganui) around 1969 - 70 from memory. ........ a lot of sideburns etc, also people with white coats! - I wonder if there was any significance in that ?? :facepalm: .......... think that was maybe a drag race day - I dunno, - think I was in hospital at the time!

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[katinas]

WilDun, wonderful photo, it should be a great feeling to see your work from another world.
It reminded me of my youth’s attempt to put together two outboard 488 cc twins, but in the end the task turned out to be too difficult. The interconnection of the engines was with the chain and the big problem was finding space for the exhaust. At that time I had no way to work with the machinery, all the tools were files, metal saws and drill. Unfortunately no photo left (red where there was a second engine)
So finished with only one engine.

[WilDun]

Yours looks to be well into the seventies (or later?) - did you design it yourself? - I don't recognize it!
Gives a lot of pleasure to look back on them ...... ours also used chain drive but the outrigger bearings gave us endless problems!

I remember not having any machinery at home so I did it at work using all their welding equipment and tube benders etc - couldn't use their lathes though (they were always locked up in the toolmakers area) - it was a furniture factory where I worked for about 1 year - the factory foreman was a good guy who, although he wasn't really interested in bikes and actually quite strict, sometimes turned a blind eye to what I was getting up to! - ( I was a MIG welder and always got my quota done ASAP before building the bike!).

Unfortunately that wasn't me on the bike - but he did probably a good 50% of the work on it (I just designed the frame, built it and fitted the engines - he did the rest to finish it off.

To tell the truth I had lost interest by then and was more interested in racing a (near new) T20 Suzuki!
Having done that, I think I really should probably have got a speedway bike, because a little later I worked with a couple of ex speedway champions, who had a wealth of knowledge and could have helped me big time - I do regret not doing that!

But - all good fun!

[katinas]

The base for this bike was Jawa 638 ( photo ), but probably difficult to recognize it.
I modified it through years and the latest version was with custom made disc brake, as I started to work at racing car factory with huge machinery in 1991.
Until now I clearly remember the first touch to disc brake lever, absolutely shock with rear in the air, after many km s with drums. Impressive feelings.
At the same time in this factory, with such good machinery, I could even make a "racing" bicycle with disc brakes and rear with thumb brake. It was in 1994 and yes Mick Doohan inspired this. I like this rear thumb brake so much and later use them on all the bikes, even on of road. Control was so natural and harmonic.

[Pursang]

Pretty Cool Will. Plus Very innovative, using a knobby on the rear for maximum Drag-strip traction!

Cheers, Daryl

[WilDun]

Pretty Cool Will. Plus Very innovative, using a knobby on the rear for maximum Drag-strip traction!

Cheers, Daryl

Well, as I said I only made the frame and fitted the engine - I wasn't there when the photo was taken,
I was in hospital (for 8 weeks) suffering from burns after having a slight mishap at a beach race (we were having a bit of a party at the end of the beach afterwards and had a fire going. A bottle of meths was sitting too close to the bonfire and it exploded all over my legs!) and I guess the beach race explains the rust! - The rear knobbly was actually used at the beach and he must have taken it to the drags "as is".
Last I heard of him was that he highsided his Bultaco at Pukekohe (at over 70 years old!) ie when his gearbox blew up :facepalm: - that cut his racing career short! I haven't heard from him for quite a few years now! - but he sure did enjoy his racing though!

Katinas,
That machine was a very impressive piece of work, and I did think that brake was a bit before it's time (moto GP have only just got near that dimeter recently!). The "push" bike is also very impressive!

[Pursang]

No reflection on you Will.;)

Did anyone else notice that Elwood Blues was a race official at that event?347405

347406

Cheers, Daryl

[WilDun]

Elwood was a man of many talents (this included being a flag marshal) - but not many realized he was actually a talent spy for Suzuki (on the lookout for budding motorcycle engineers!).- but he was out of luck on that occasion, cos I wasn't present! :rolleyes: :msn-wink:

[Pursang]

:msn-wink::laugh:

[Grumph]

Will, that pic is a perfect period microcosm. So much is familiar even though I never got to Baypark in the period.
The tank shape is familiar - seen it many times but can't remember who made them. The tacho is the only one available in NZ at the time which would go over 10 grand. they're a pos. Mine is somewhere here still reading 1500rpm....
The crowd so close. Normal then. Sidecar Bob could probably put names to some of them too.

The back brake operating arm is impressive. No lack of leverage there, lol.

[WilDun]

Will, that pic is a perfect period microcosm. So much is familiar even though I never got to Baypark in the period.
The tank shape is familiar - seen it many times but can't remember who made them. The tacho is the only one available in NZ at the time which would go over 10 grand. they're a pos. Mine is somewhere here still reading 1500rpm....
The crowd so close. Normal then. Sidecar Bob could probably put names to some of them too.

The back brake operating arm is impressive. No lack of leverage there, lol.

Glad to see that pic, I was beginning to think that all these memories were just a figment of my imagination and I thought, 'gone forever'!
I have never seen that pic before ........ unfortunately I was too engrossed with the bikes to ever think about taking photos myself!.

As you more or less said, it was a rare find and should be treasured - not just for the bike (which was built from parts we had lying around and was just for a bit of fun), but the whole sixties/seventies NZ scene.
If the guy who was riding it is still around, (he'd be over 80 now), he would no doubt be very pleased to see that photo!
Maybe we shouldn't discuss the brake linkage! (perhaps we figured it might be needed when the brake drum at the front faded! :msn-wink:) - I really don't know if there was any theory behind it at all - a mystery!

[jbiplane]

JB, the 4.2 kg weight is impressive, but the fuel consumption of 800 gm/kWhr isn't
Chinese Foxtech design not the state of art, just working and increasing range in 4+ times related pure electric. I saw other 2-stroke UAV 11kw 180cc engine which use direct injection and have rather impressive 280gm/kWhr and multifuels. It use air injection system originated from 50cc italian scooters.

[ken seeber]

JB, from your description it sounds like the Orbital 2 fluid system. 280 gm/kWhr is good. If you have a look at this, you'll see that Orbital till makes engines, specifically for drones: https://orbitaluav.com/propulsion-solutions/. I thought that they were only 50 cc units, but they may have increased the capacity to the 180 cc to cater for larger drones.

One of the key selling features is that it can run spark ignited on heavy fuels, eg Jet Fuel A due to the very good atomization due to the compressed air being a propellant for the fuel charge. Jet Fuel A is a requirement set by the US military so that the majority of all their transport (sea, air and land) can run on the same fuel, this being for logistical reasons.

Might sniff around to see what engine capacities they are working with.

[jbiplane]

it sounds like the Orbital 2 fluid system
Aprilia of DiTech Di = Direct injection / Tech = Technology
Piaggio/Gilera's = PureJet.

[husaberg]

Aprilia of DiTech Di = Direct injection / Tech = Technology
Piaggio/Gilera's = PureJet.

both owned by same company...........
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[breezy]

https://youtu.be/t3zzD3sp5zo

[katinas]

Inner face of "Fieseler Storch" Argus As 10C engine piston.

[Stefan38]

WilDun, alloy part with piston pin is threaded into the steel tube. Tube wall thickness 1.3 mm.
All this complicated piston construction, with small fixing bolt inside, is designed only to make engine as compact as possible, but at the same time maintaining a longer thrust for smaller piston part at TDC (28 mm in my case ) and not to let piston pin hole to clash with lower cylinder seal as masked gudgeon pin is higher than seal at TDC.
So with 50.6 mm stroke, the minimum height of additional plate under the cylinder, that I could do, was 20 mm.
But after every test threaded part little lose, so it s not a good solution. Maybe longer height of that threaded small part could help, but fixing still needed.
Perhaps better chose solid piston with thin steel liner (I even already have it made from a tractor piston pin 38 mm dia. x 0.9 mm thick) and open hole for piston pin from one side, with normal circlip. Of course this add another 8-10 mm to plate so cylinder must be rise from 20 mm to 30 mm.
On Ryger pistons they use special key for pin from one side, but they still must use two bolts to fix it. Narrower part of Ryger piston was coated.

Can you tell me anything else on the Ryger? They still in business?

[katinas]

Can you tell me anything else on the Ryger? They still in business?

Hi Stefan,

In fact I know nothing about Ryger group, except what has been published in various forms on the internet. So I can’t say anything further about their work.

I still think that stepped piston concept is the simplest of all possible options to separate crankcase and use the fuel without oil. And no additional moving element.
Another question is how to take advantage of the stepped piston for scavenging.

I nearly started again with stepped piston on NSR 250 crankcase, but decide to continue my tests with direct to transfers scheme, with inside reed valve.
This time with 54 mm stroke and Honda RS gp cylinders, adapted to Honda NS 400 crankcase.

[husaberg]

Always cool stuff Kat

I have seen this on a trawl today.

https://www.youtube.com/watch?v=k_MrPylnsDg&t=1088s

[shoom]

Seems like at least one has been located, I doubt they ever sold many at all
https://www.facebook.com/116916108330930/posts/cb350-k4-4-valve-dual-cam-cylinder-head-with-central-located-spark-plug/786227134733154/


I'd be surprised if that survives. Probably re-engined in period.
Lyster's next step was an 8 valve head for the CB450 - which was a much better package and easier to do.
The one he did do became the property of the American who paid the bills - he got the patterns too.
At the time of Colin's death he was working on patterns to recreate the 8V honda heads.

[husaberg]

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

[katinas]

JU-87 Stuka engine gear. Looks like teeth edges rounded directly in form at forging process.

[Frits Overmars]

JU-87 Stuka engine gear. Looks like teeth edges rounded directly in form at forging process.I wonder what purpose this rounding might serve. Maybe to maintain an oil film between the side of the gear and whatever it may be leaning against in case of lateral forces?

[katinas]

The first thought that comes to mind, is teeth cracking prevention. This is the crankshaft gear that turns propeller gear.

[190mech]

Yes,I agree that those fillets are to prevent cracking in that highly loaded part..I continue to be amazed at the very high quality of the parts built during wartime conditions with manual machines from all of the nations..My hat is off to all of the masters who have lived before us and that we may continue in their foot steps!

[Muhr]

I read a bit about that a while ago.
https://www.geartechnology.com/issues/0584x/geardesign.pdf

[ken seeber]

This makes con rods just so "ho hum"....

http://www.nadiraksoy.com/

[ceci]

This makes con rods just so "ho hum"....

http://www.nadiraksoy.com/



It reminds me of how diesel pumps work.
This type of pump is serving as an orientation to create a specification for the two stroke engine
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[lohring]

Radial piston hydraulic pumps and motors have been built in a similar way for years. The translation into an IC engine hasn't worked. It's a lot harder to seal a piston that's not bathed in oil at moderate temperatures.

Lohring Miller

[katinas]

Finally engine run today with intake through transfers type, adapted for Honda RS 125 GP cylinder. Still not ready for riding or dyno tests, just checked if this could work at all, without damage. Add short video https://www.youtube.com/watch?v=uK-MLMWTl-g

[ceci]

Finally engine run today with intake through transfers type, adapted for Honda RS 125 GP cylinder. Still not ready for riding or dyno tests, just checked if this could work at all, without damage. Add short video https://www.youtube.com/watch?v=uK-MLMWTl-g

Very beautiful, it is a pleasure to behold.
Excellent work, I keep seeing them over and over again.
congratulations on a job well done

[katinas]

Thank you Ceci, but I have some doubts. Intake through transfers scheme, with Honda Rs cylinder, have one down side. Two wide exhaust ports restrict intake ( red zone) through whole A transfers area. Only at TDC piston fully uncovered A. With one exhaust port type cylinder, A is not restricted, but exhaust became restricted.

[ceci]

Thank you Ceci, but I have some doubts. Intake through transfers scheme, with Honda Rs cylinder, have one down side. Two wide exhaust ports restrict intake ( red zone) through whole A transfers area. Only at TDC piston fully uncovered A. With one exhaust port type cylinder, A is not restricted, but exhaust became restricted.

I disagree that the problem is filling, I see more restrictions in the evacuation of cargo trapped in the crankcase

[ceci]

I disagree that the problem is filling, I see more restrictions in the evacuation of cargo trapped in the crankcase

The imperfect evacuation of charge from the crankcase becomes an intake problem

[katinas]

The imperfect evacuation of charge from the crankcase becomes an intake problem

Yes, this could be huge restriction if the all flow mass, that goes into crankcase through A and B, evacuated only through the bottom crown side reeds.
But with this concept, I guess the most interesting thing is that the bigger part of the mass flow returns to the transfers channels, again through A and B windows when the piston moves down. The previous inertial flow from carb collided with returned flow, intake reed valve closes and all this increases the high pressure in the transfers tunnels. And this is why, maybe it is possible extract something from this concept.
Yes, crankcase separation crown with reeds, just needed to evacuate what left in the crankcase and later this helps to increase negative pressure just before the intake process started through A and B, when piston moves up.

As flow through A and B goes in both directions, before they opened for scavenging, even small restriction could be critical for build up high pressure in transfers tunnels.

Would be good to do three main comparisons tests with the same cylinder.
1 Spec piston and separation crown with side reeds (intake through A and B).
2 Spec piston and opened crankcase ( normal intake )
3 Std RS 125 piston and opened crankcase ( normal intake )

Still not ready for tests, but not many things left to do.

[katinas]

Finally finished tests with direct to transfers intake configuration. No dyno, just all road tests 800 km, always on the same 3km section, so just comparison between different configurations, but this enough to feel the engine reactions.

Test engine
Honda NS400 crankcase with adapted modified NSR 250 (54,5mm stroke) half crankshaft to 1cylinder.
Cylinder Honda RS 125 gp, with 22,5mm thick plate between cylinder and crankcase for reed intake route. Because of this conrod length 120mm ( original NS400/250 and latest Honda RSW 250 109mm and std RS125/250 104mm)
Carburetor Mikuni TMX05 38mml in non pressurized airbox, reed valve cage RGV 250 with manifold from Polaris Sportsman 500 HO
Ignition Honda RS 250 1987 (some tests with Honda CR 125 2003 ignition, but rev limiter at 13700rpm. )
Pipe Honda RS copy stainless 0.8mm

Pistons for normal configuration
1. Honda RS 250 nx5 A kit locating pin at C
2. Custom made identical to Honda RS 250 just with lowered side transfer cutouts, at the level that A and B is closed when piston at TDC.

Piston for direct to transfer intake configuration, custom made from 2618 alloy with special shape that works together with crankcase, one way flow, separator. Intake duration through A,B fixed at 206 degrees.

After many back-to-back tests, with huge other small changes, the power with standard configuration were higher from low to 10000 /10500 rpm and more or less similar at max 13000 rpm.
There was not a surprise of lower output at mid range, because very similar reaction was from previous last year test with one exhaust port NS cylinder. But doubts about restricted intake through A (because of wide two exhaust port Honda RS cylinder), seems confirmed, as no improvement at top end over standard configuration.

Honestly I was happy, that for this 3-cylinder NS project with RS barrels, no need to do complicated pistons and crankcase separators, until decide to do last modification with direct to transfers intake configuration.
So finally decided to destroy cylinder and cut two compensation intake passages under front part of A, positioned at same angle where exhaust overlapped A. Passages opens and closes at the same time with A and B. The total additional intake area corresponds to 18mm dia.

The engine reaction was what I looking for. From 10000 to 13000 rpm the best output of all tests after four moths, wheelie in 1 and 2 gear. Mid range better than before, but not higher than with standard configuration. And most importantly, it was repeated on other days.

I guess that if A opens fully all the way like B, without piston skirt restriction, engine goes even better without additional passages, but this is impossible to do with exhaust ports that partly overlapped A. and A fully opens only short time just at the moment when piston is at TDC

[Frits Overmars]

Something I just encountered on that other great forum ( http://www.pit-lane.biz/t117p246-gp125-all-that-you-wanted-to-know-on-aprilia-rsa-125-and-more-by-mr-jan-thiel-and-mr-frits-overmars-part-1-locked ).

Nothing to do with motorcycles, but this is definitely a two-stroke:
https://www.youtube.com/watch?v=bsSo34HQCac#t=1m30s (https://www.youtube.com/watch?v=bsSo34HQCac#t=0m50s)

Now this has something to do with motorcycles:
350072

Your thoughts please?

[katinas]

Something I just encountered on that other great forum ( http://www.pit-lane.biz/t117p246-gp125-all-that-you-wanted-to-know-on-aprilia-rsa-125-and-more-by-mr-jan-thiel-and-mr-frits-overmars-part-1-locked ).

Nothing to do with motorcycles, but this is definitely a two-stroke:
https://www.youtube.com/watch?v=bsSo34HQCac#t=1m30s (https://www.youtube.com/watch?v=bsSo34HQCac#t=0m50s)

Now this has something to do with motorcycles:
350072

Your thoughts please?

Never interested in hammers before, but indeed from video looks like two stroke open engine with real piston, thank you Frits


But for motorcycle, some backward horizontal force occurs on arc, when the cylinder falls down and gradually changes direction from vertical to horizontal, too.

Reminds me old compressor ( engine on the paper), just because of "arc traveling" nothing more.

[Ocean1]

Nothing to do with motorcycles, but this is definitely a two-stroke:
https://www.youtube.com/watch?v=bsSo34HQCac#t=1m30s (https://www.youtube.com/watch?v=bsSo34HQCac#t=0m50s)

The Russian army tried strapping those to their feet.
And they could out-run an unequipped runner. Briefly.

[Frits Overmars]

Some reading for the weekend:

www.techbriefs.com (http://www.techbriefs.com)

www.createthefuturecontest.com (http://www.createthefuturecontest.com)

https://contest.techbriefs.com/2021/entries/10870

[lohring]

More HCCI engines. It's a four stroke, sleeve valve engine. They obviously didn't read Ricardo on sleeve valves, but because of the seal type lubrication might not be a problem.

https://www.greencarcongress.com/2012/04/pinnacle-20120424.html

Lohring Miller

[WilDun]

More HCCI engines. It's a four stroke, sleeve valve engine. They obviously didn't read Ricardo on sleeve valves, but because of the seal type lubrication might not be a problem.

https://www.greencarcongress.com/2012/04/pinnacle-20120424.html

Lohring Miller

Lohring, - just having a quick look in after a long time - I see you have not been fully sold on the EV just yet! (guess you are part way there though!)
If we refuse to convert to electricity, then we will all be forcibly removed by those in power (or who want to be! as we are seeing in some countries today!) ...... These people in power (in every nation) have already more or less suffocated the two stroke to death, next the four stroke? - we are in a rapidly changing world - our old post war freedoms and opportunity to be enterprising quite frankly are disappearing fast! - (mine are now long gone with changing times within the family anyway!) :facepalm:
Bright future! -
Then again, I could bury my head in the sand, become an optimist and tell myself not to worry and that it'll come right, but I feel somehow that I'll need to stop myself aging in order to ever see that! ........ (What a misery guts! :rolleyes: ) ........... Happy new year! :laugh:

[lohring]

Will, I'm very sold on my Tesla, but I love the complexity of IC engines. Two strokes are even more fascinating since even modern computers have a hard time simulating all the aspects of their operation. However, my Tesla costs at least $100 US less to operate per month than my last IC car. For that it has used an average of 300 kW per 100 miles over the last 50,000 miles. That's around the equivalent of 100 miles per gallon. I also get the ability to accelerate from say 45 mph to close to 100 mph in the length of a semi when I pass. Autopilot makes highway driving much more relaxing, and it pays better attention to traffic than I do. Over the air updates fix most issues and improve the basic car. In contrast my wife's Hyundai needed the engine replaced because of a software glitch in the knock sensor.

I'm afraid the handwriting is on the wall, but it will take years for the complete transformation. After all, we still have horses, just not for every day transportation. Old guys like us will still love the sound of a big V8 or aircraft radial at startup.

Lohring Miller

[WilDun]

Will, I'm very sold on my Tesla, but I love the complexity of IC engines. Two strokes are even more fascinating ............. .However, my Tesla costs at least $100 US less to operate per month than my last IC car. ..... around the equivalent of 100 miles per gallon.

I'm afraid the handwriting is on the wall, but it will take years for the complete transformation. Old guys like us will still love the sound of a big V8 or aircraft radial at startup.............

Lohring Miller

Yes it will all be good for cities to have EV and also will be good in all the developed countries with a solid infastructure (if it's not destroyed by lunatic Presidents (many candidates for that role these days!) - There are many countries where there will never be any noticible infrastructure - and I guess the humble two stroke in another form (generator) could be beneficial! - but I recently advised my son not to get an electric car (maybe I shouldn't have) for driving up here to (Auckland - a two hour country trip) each week for a couple of days - he pointed out how cheap it would be and I said that when this thing gets in full swing the power stations (here in NZ ) will not be able to cope (we use hydro) and the price of electricity would soar! so I advised him to wait also because there were much better batteries on the horizon so then his nice new electric car would become obsolete! - He has a little old school Mazda now (which is well proven and economical) and which will serve him well in the interim! - just hope I was right! ........ But - horses for courses I guess!

[lohring]

New Zealand is a lot like Oregon where I live. Most of our power comes from dams and wind in the Columbia river gorge. Most of my charging is done at home nights and is good for trips of around 200 miles if needed. I bet there's plenty of power available late at night or early in the morning for home charging.

Fast chargers are needed for trips. However, they cost twice as much as home charging. New Zealand's long narrow shape makes locating charging stations easier and there are a lot of them. See below. I usually need to stop every 2 or 3 hours to pee or eat. The car usually charges at these stops and is ready to go when I'm ready.

Take a look at the power plant of a dual motor Model 3 below. Those two red objects put out somewhere between 450 and 500 hp in my car when you need it. Imagine what commercial IC engines with this performance look like.

Lohring Miller

350840 350839
350841

[WilDun]

New Zealand is a lot like Oregon where I live. Most of our power comes from dams and wind in the Columbia river gorge. Most of my charging is done at home nights and is good for trips of around 200 miles if needed. ...........

........ Take a look at the power plant of a dual motor Model 3 below. Those two red objects put out somewhere between 450 and 500 hp in my car when you need it. Imagine what commercial IC engines with this performance look like.

Lohring Miller



Yes there are strong similarities between here and Oregon - especially our South Island! - I guess we are ok for power etc etc, (in the meantime) but will probably need to build new hydro plants! - but I guess someone will eventually try to give us a "good deal" on a Nuclear plant! (with lots of reassurances to clinch the deal!) and we'll take the easy way out! - however, these little islands of ours are not called the "Shaky Isles" for no reason and we do need to take notice of what happens in Japan! - BTW I use a mobility scooter and to be honest I think that electrics are excellent! - but batteries (in cars etc) still do require some attention regarding cost and durability and how to dispose of them! - but the torque and simplicity of an electric motor is unbeatable! - now, ........ we just have to find a spot for a two stroke powerplant somewhere in the equation ! :rolleyes:

[WilDun]

Just having the customary look in here again and nothing has moved (got to get it moving again!)

Looks like the battle between Hydrogen and Battery Storage is still on! - It seems that someone has found a way to store Hydrogen in Silica without needing to be pressurised at all and is safe to transport (much safer than most conventional fuels or lipo batteries)

it is essentially sand (somehow) containing Hydrogen, which can be released just by the addition of good old H2O!! This is then good for use in either internal combustion engines or to produce electricity from a fuel cell!
They say it is already reality and sounds like it might be a great solution.

As always, I guess we shouldn't just dive in straight away, at least until it has been proven on actual vehicles! but here's hoping! at least it is a (last) chance to extend the life of the fast dying good old Two Stroke!

https://interestingengineering.com/innovation/silicon-based-powder-transporting-hydrogen-fuel

https://www.epro-atech.com/media

[Frits Overmars]

It seems that someone has found a way to store Hydrogen in Silica without needing to be pressurised at all and is safe to transport (much safer than most conventional fuels or lipo batteries)

it is essentially sand (somehow) containing Hydrogen, which can be released just by the addition of good old H2O!
https://interestingengineering.com/innovation/silicon-based-powder-transporting-hydrogen-fuel
https://www.epro-atech.com/mediaStoring hydrogen without the need to pressurize or cool it is commendable. But I can't see me refueling first with a shovel and then at a water pump. And do I have to remove the sand that is formed after extracting the hydrogen with that shovel or can I just scatter it on the street? That would be good in slippery winter conditions.

I still think the best way to store hydrogen atoms is to package them between carbon atoms: the so-called hydrocarbons; you may have heard of those.
You can already get hydrocarbons at every gas station these days. A reformer under the hood can release the hydrogen. The efficiency will be slightly lower than that of pure hydrogen, but on the other hand the infrastructure is ready-made, which you cannot say for gaseous or liquid hydrogen. And what remains of the efficiency of pure hydrogen if you first have to produce the stuff, then cool it, compress it and transport it?

[WilDun]

Storing hydrogen without the need to pressurize or cool it is commendable. But I can't see me refueling first with a shovel and then at a water pump. And do I have to remove the sand that is formed after extracting the hydrogen with a shovel, or can I just scatter it on the street? That would be good in slippery winter conditions.

I still think the best way to store hydrogen atoms is to package them between carbon atoms: the so-called hydrocarbons; you may have heard of those.
You can already get hydrocarbons at every gas station these days. A reformer under the hood can release the hydrogen. The efficiency will be slightly lower than that of pure hydrogen, but on the other hand the infrastructure is ready-made, which you cannot say for gaseous or liquid hydrogen. And what remains of the efficiency of pure hydrogen if you first have to produce the stuff, then cool it, compress it and transport it?

Everybody needs a little excercise sometime and I would prefer shoveling that stuff than trying to dig a grave for an extinct battery or be blown to kingdom come by an exploding hydrogen cylinder (that sand would probably be fine for making casting patterns in my next home foundry, in my next garage, for my next two stroke engine (but I haven't asked the boss lady yet if that's ok!) - I'm sure she will be quite enthusiastic when I explain it all to her!
:rolleyes:

[OopsClunkThud]

There's been some advancement on solar to syngas as well

https://www.cell.com/joule/fulltext/S2542-4351(22)00286-0?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com %2Fretrieve%2Fpii%2FS2542435122002860%3Fshowall%3D true#secsectitle0010

[husaberg]

I was reading about the cross rotary valve it turned out he invented a new kind of way of making piston rings whist he was doing it and lost interest as that was great money spinner.
What i would like to know is could a lab seal be used to provide a gas seal?
i understand the rotary valves biggest issue is distortion with it seemingly being ceramics not providing the complete solution as "coates" have been working on this for 20 years.
the early ones cooled with copious oil to lube and cool but it was dirty

Could the rotating ball housing have sodium in it to splash around to even up the heat.

351561351562351563

The two spherical ones with two valves have advantages bit maybe these are also disadvantages.

https://www.youtube.com/watch?v=vjHkAgi9TbY
https://www.youtube.com/watch?v=pDsRa4eT7co

one of my first posts was a Aussie diy one i like better.

351566351565351564

[lohring]

Sealing is always the issue with the various rotary valves. A steam engine designer commented there are poppet valves and valves that leak. I observed a rotary valve Crosley 4 cylinder engine that had been converted to overhead rotary valves. I think it used the Cross design. A wealthy friend of my family financed the project. The engine ran fine, but burned too much fuel for its size. The idea was to sell it as an outboard power head. This was around 1960 and the project died.

Lohring Miller

[WilDun]

Looks like all these ideas failed because of the lack of adequate lubrication! and years of research got them nowhere!

I thought well, the piston seems to work ok these days for sealing off the gases, then why not replace these rotary valves with pistons instead! So I delved in to it and came up with a brilliant idea which I reckoned might work and thought, why not use opposed pistons instead!
However I have found that someone else had already come up with the very same idea about 100 years ago! :msn-wink: and also some guy down in the Waikato was currently having a go!! :facepalm: (wouldn't you know it!).

So I've had to revise my thinking and I found this stuff which could fix the lubrication problems encountered with those rotary valves in the head, also the (perceived) pollution problem of the two stroke!

https://www.mining.com/platinum-gold-alloy-wear-resistant-metal-world/

This of course could be just a tad expensive, (using Platinum coated with gold) but why not give it a try!- and imagine a cylinder bore coated with the stuff - practically oil free! - of course I have not got the wherewithal to do this (only imagination) - Got to be the answer! :msn-wink:

[ceci]

However I have found that someone else had already come up with the very same idea about 100 years ago:

That tends to happen much more than we think, when you have time to search the Japanese patent office, you discover that much of what you thought was innovative, the Japanese had patented several decades before.
The more I investigate in the past, the more I see that the present has nothing innovative

[husaberg]

“I think there is a world market for maybe five computers.”

Thomas Watson, president of IBM, 1943

“Television won’t be able to hold on to any market it captures after the first six months. People will soon get tired of staring at a plywood box every night.”

Darryl Zanuck, executive at 20th Century Fox, 1946

“Almost all of the many predictions now being made about 1996 hinge on the Internet’s continuing exponential growth. But I predict the Internet will soon go spectacularly supernova and in 1996 catastrophically collapse.”

Robert Metcalfe, founder of 3Com, 1995

“Apple is already dead.”

Nathan Myhrvold, former Microsoft CTO, 1997

;)

[WilDun]

That tends to happen much more than we think, when you have time to search the Japanese patent office, you discover that much of what you thought was innovative, the Japanese had patented several decades before.
The more I investigate in the past, the more I see that the present has nothing innovative

Ceci, - Although the bearing part is essentially true and worth a look at least!, I did mean the idea of having discovered "opposed piston" to be a silly joke (which backfired).

Yes, there are no longer all the "breakthroughs" we used to get in the last century! but there will also be a lot of lapsed patents from that time - which need to be looked through (you have found quite a few already) and probably which could inspire a starting point for other designs!

The evolution of electric vehicles has somehow upset the flow!

[WilDun]

“I think there is a world market for maybe five computers.”

Thomas Watson, president of IBM, 1943

“Television won’t be able to hold on to any market it captures after the first six months. People will soon get tired of staring at a plywood box every night.”

Darryl Zanuck, executive at 20th Century Fox, 1946

“Almost all of the many predictions now being made about 1996 hinge on the Internet’s continuing exponential growth. But I predict the Internet will soon go spectacularly supernova and in 1996 catastrophically collapse.”

Robert Metcalfe, founder of 3Com, 1995

“Apple is already dead.”

Nathan Myhrvold, former Microsoft CTO, 1997

;)


Yep, all true nobody knows what's ahead! (except me!).:msn-wink:

(and I have grave doubts about " The Two Stroke" - (The Return Of.) -

but there is still hope! (don't forget the compactness and Power to weight ratio!)
Still a couple of little details to "clean up" etc and it'll make a spectacular return when they all come to their senses!
.

[ceci]

Ceci, - Although the bearing part is essentially true and worth a look at least!, I did mean the idea of having discovered "opposed piston" to be a silly joke (which backfired).

Yes, there are no longer all the "breakthroughs" we used to get in the last century! but there will also be a lot of lapsed patents from that time - which need to be looked through (you have found quite a few already) and probably which could inspire a starting point for other designs!

The evolution of electric vehicles has somehow upset the flow!

I'm sorry for not understanding your humor.
The world of the two stroke engine is very beautiful, that beauty catches you and that leads you to want to know everything about it.
You feel a contradiction when you discover that you were enthusiastic about it and that you currently believed "in evolution projects". These already existed before, and the question is whether these people who present it as "innovative" were already aware of its existence

[ken seeber]

Over here in Western Australia, we have a lot of development going on with renewables, particularly wind and solar, the main application for local usage (particularly in mining) and the potential to export the energy. One in particular is:

https://ffi.com.au/technology/green-ammonia/

As you can see, normally "Ammonia is a colorless highly irritating gas with a sharp suffocating odor. It dissolves easily in water to form ammonium hydroxide solution which can cause irritation and burns. Ammonia gas is easily compressed and forms a clear, colorless liquid under pressure", but the stuff made here is green.;)

Lots of apparent effort going into using hydrogen and ammonia as a combustible fuel.

Just hope that the huge number of required solar panels can be made here rather than from China where they value add the raw materials from Australia. :weep: Also the wind turbines and towers.

[lohring]

It's more than solar panels and wind turbines. Australia is on the cutting edge of the new power generation.
https://en.wikipedia.org/wiki/Hornsdale_Power_Reserve

Lohring Miller

[WilDun]

That does looks like great research! - maybe there still some great breakthroughs still to be made!

Around maybe 30 years ago, there was a burst of energy with research into using Silicon Nitride (basically pressed / sintered silicon powder which was nitrided in the same fashion as steel (done at relatively low temperatures using Ammonia Gas) - this was being promoted as a possible great material for cylinder bores (even totally ceramic engine castings) - seemingly an extremely lightweight, hard and shock resistant ceramic material - anyone here know why that didn't ever actually come to pass?

[Toki]

The main problem with rotary valve head engines is when they use oil to cool and lubricate the valves.
Unlike poppet valves, they introduce oil-wetted, moving surfaces to the combustion chamber, resulting in burnt oil and smoke.
Labyrinth seals work well for 2 stroke crank chambers, but then there are no hot gases to control, and pressures are relatively low.
Tests with un-oiled (eg graphite sealed) rotary valves reportedly did not produce good results - maybe because being carbon, they burnt.
Maybe one day they'll invent some new material that will cope.

[husaberg]

Odd (lab seals) can seal a turbo and a gas turbine, both were developed with a war time rush and unlimited funding.
Lots of gas turbines use lab seals as do some steam turbines
from wiki.

modern high-performance gas turbines use dry gas seals which use spring-loaded rings with an inert gas in between the faces of the rings to provide the seal. This creates even lower friction and provides a liquid-free seal


Labyrinth seals on rotating shafts provide non-contact sealing action by controlling the passage of fluid through a variety of chambers by centrifugal motion.

there is another from of Lab seals that were used on two stroked that used piston rings First time i seen them used was on the DKW threes
i have posted pics before.
351689
STD lab seal convoluted path Yamaha type this on is TZR250

351690351691
above piston ring types
you will note similar ring seals well grooved for the rings mentioned in the text on the aussie rotary valve i posted a few pages back
351692351693

Before materials (most developed funny enough for gas turbines ie austenitic steel) caught up with HP development things like sodium filled valves were used to help dissipate the heat. not cool all they do is move heat. From the head to the stem
Nuclear reactors French and i think us have been built with internal sodium used as a heat transfer medium.
“Superphénix,”
(not to be confused with molten salt reactors)

Norton Creighton (i think rather than hele) designed a system that used a vacuum form the exhaust to draw air through the middle of the rotors to cool the Norton rotary
originally it had a system that used its air charge to cool the rotors which is not great for power obviously

With an engine from a scrapped police Interpol and working out of the caretaker’s shed at Norton’s Lichfield base, Crighton’s masterstroke was coming up with what he called the ‘exhaust ejector’ which, similar to two-stroke expansion chamber theory, used the notoriously hot rotary’s exhaust venturi to drag cooling air through the engine’s internals in turn allowing air for the carbs to arrive unrestricted.

The effect almost doubled the rotary’s power output and also made it incredibly loud, although for racing purposes that didn’t really matter…


Norton rotary, Cycle's April 1990 article.

"Unlike most other Wankel rotaries, the Norton engine uses air rather than oil to cool its rotors. This reduces internal friction and makes for a
mechanically simpler engine, at the expense of having to route intake air
along a convoluted path.

"Entering through air filters inside the right and left sides of the fairing,
twin airstreams travel down through the rotor bearings (lubricated by
two-stroke oil), cool the spinning rotors from the inside, then meet in the
engine's middle before being drawn up and out into a plenum chamber. From there, the air enters the two 34mm Mikuni downdraft carbs and is charged into the combustion chambers."

"On the race bike, a simpler, more effective intake system is used:Carburetors pull cool air directly from the atmosphere, while the rotors are cooled by air sucked through the engine and into the exhaust by an air-ejector system (which means the two-stoke oil that lubricates the engine passes through unburned). Those two modifications win an extra 30 horsepower, but aren't practical for road use."


but hey if it was easy to would be done already....
was looking for the air cooling system and found this worth a read
https://www.nortonownersclub.org/history/rotary

[Toki]

Interesting to see the DKW all-metal seals, just like the one in my Goggomobil bubble car (centre seal).
I wouldn't have thought of it as a labyrinth seal though, as it relied on sliding parts rather than no-contact labyrinths.

I didn't know about turbines having lab seals.
I imagine they wouldn't be as simple as the one in my Yamaha YL-1.

[pete376403]

Not sure if this has been posted here yet but anyway. The bike will be on display this weekend in the BSA club show at Upper Hutt
https://www.engrichmotorcycle.nz/

[Flettner]

Willdun, Im just going to run with this for now, my twostroke future, as it were 😁. Finaly found the time and got the bugger off the dyno for a rip around Saturday, angry yet refined is the best way to describe it, vairable rotary disc valve TPI engine, E85 fuel. It goes real well.

[husaberg]

Willdun, Im just going to run with this for now, my twostroke future, as it were ��. Finaly found the time and got the bugger off the dyno for a rip around Saturday, angry yet refined is the best way to describe it, vairable rotary disc valve TPI engine, E85 fuel. It goes real well.

For some reason i have a strong urge to feeding candy down the lid of it. I have no idea why.

the cover on the left side looks awesome.

[WilDun]

Willdun, Im just going to run with this for now, my twostroke future, as it were �. Finaly found the time and got the bugger off the dyno for a rip around Saturday, angry yet refined is the best way to describe it, vairable rotary disc valve TPI engine, E85 fuel. It goes real well.


Neil,
Very impressed with your perseverance and it must feel great to have it all working - congratulations!
Not many people are prepared to put in the effort to get that far!
BTW, I see you have abandoned the side tailpipe and gone for the scooter type of setup (just for convenience?).

I wish I had started doing stuff much earlier (too late now!) but unfortunately, when you called in to my place I was already well on the way out ( health and mobility wise) - but the little bit I did do, really was all great fun
I did manage to design and build my own little home foundry and do a few pours - this was all inspired by your efforts! and it also got me interested in bikes again after many years away from them - that also made me feel good!
I was hooked on foundry stuff ever since the fateful day when I got a severe bollicking for walking over what I thought were "sand dunes" which actually were just finished moulds, ready for the CI pour!! - (that was at in the local foundry, when I was a schoolkid nearly 60 years before).

We have just sold our house and will probably be moving to the Tauranga area soon (where the family live).
Also probably where we eventually will end up, - Probably it will have nowhere with even a hint of a workshop! - (which I predicted was going to happen!). - That's life I guess! ....... reduced to activities such as bowls, croquet and snakes and ladders next! (like hell! - got a lot more left in me yet!).

Well done with your new "Yamahintz"! - please keep us advised on it's progress!

[ken seeber]

What is that tapping sound ??
Big ends gone ??

https://newatlas.com/automotive/two-piece-con-rod-thunder/

Might not need cammed piston skirts though..

[lohring]

I would think that the resulting short rod would put more load on the piston skirt. I always felt that placing the wrist pin high in the piston was the way to go. Also, that looks like a great way to make a heavy piston. Again, we thinned our pistons as much as possible; sometimes to the point of failure.

Lohring Miller

[Frits Overmars]

I always felt that placing the wrist pin high in the piston was the way to go. Also, that looks like a great way to make a heavy piston.What makes you say that, Lohring? The bulk of the piston mass is situated between the crown and the piston pin bores, so putting the pin as high as possible is the best way of weight saving that I can think of..

[lohring]

Sorry, my answer wasn't clear. I always advocated for a high wrist pin placement. The pictured system for lowering the wrist pin not only should cause more side loads but also adds reciprocating weight to the piston. The performance should be poorer with the two piece rod system.

Lohring Miller

[husaberg]

Posted for Greg, as a former Manx owner i thought he might appreciate this.

https://www.youtube.com/watch?v=hoLBOWaVdqQ
Even makes decent sounds

[Frits Overmars]

Even makes decent soundsStill sounds like a foul-stroke to me. Must be my hearing aids cheating on me:scratch:

[Grumph]

Not a fan thanks Husa. That much effort building it and it still uses those wheels.

[husaberg]

Still sounds like a foul-stroke to me. Must be my hearing aids cheating on me:scratch:
As far as fourstrokes go i can appreciate a high reving V twin or small multi

Not a fan thanks Husa. That much effort building it and it still uses those wheels.
i like the premise, the tank si so well done but yes the wheels d let it down especially as they do a kit to convert comstars to spoked wheels. but ti was mainly to wind up purists i guess.

https://www.gazzz-garage.com/2019/06/05/honda-cbx550-wheels-exploded-view-backstage/


352277

[Frits Overmars]

As far as fourstrokes go i can appreciate a high reving V twin or small multiSo can I Husa. https://www.youtube.com/watch?v=hjZWrvUGAV8

[katinas]

Just two years ago, we discussed the use of two-stroke engines in WW2. And now, it's hard to imagine how two-stroke engines could be used in a worse way than they are now over a Ukrainian city.
Post Soviet terrorist , with Putin in command, use Iranian Shahed 131 drones with Wankel engines and Shahed 136 with 4-cylinder two-stroke MD 550 types engines, copies of Limbach. Ukrainians immediately called them mopeds. Russians renamed them to Geran.

Add video of Shahed 131 drone attack over Kiev. From 20 seconds can be heard clearly the sound of Wankel rotary engine. In peacetime, this sound was heard in a different way, but in the context of the war in Ukraine, it sounds terrible. https://www.youtube.com/watch?v=YcRSlBCr-bo

What the Ukrainians have done is a real miracle. Standing up to such a post-Soviet monster in the first months of the war without greater support, just a miracle . Since the beginning of the war, it was difficult to do anything, I put all my project aside. Thanks of great support to Ukraine now, from many countries.

[WilDun]

Just two years ago, we discussed the use of two-stroke engines in WW2. And now, it's hard to imagine how two-stroke engines could be used in a worse way than they are now over a Ukrainian city.
Post Soviet terrorist , with Putin in command,............................Thanks of great support to Ukraine now, from many countries.

To relegate the two stroke engine to a sacrificial end (exactly the same way as he is treating his own people!) is totally inexcusable (and inexplicable!) - all because of a dream of greatness ! - This for him will end in either death or misery living in a bunker till that will most certainly happen in a few years time!) - what is he thinking? :weird:

[katinas]

To relegate the two stroke engine to a sacrificial end (exactly the same way as he is treating his own people!) is totally inexcusable (and inexplicable!) - all because of a dream of greatness ! - This for him will end in either death or misery living in a bunker till that will most certainly happen in a few years time!) - what is he thinking? :weird:

Hi, WilDun
The best actions illustration of the Putin's terrorist army in Ukraine, could be just this one photo. This mine was found in a piano by a Ukrainian family, when they returned to their home, after liberating one of the cities from the terrorists of Putin's army a few months after the start of the war, last year.
Other photos, just part of "collection" that was landed on Ukrainian cities.
In the last photo, is bombed location near Kiev, where was damaged main Ukrainian's "Chaika" ( Gulls ) racetrack.

[pete376403]

Not just the bad guys* - https://www.liquidpiston.com


*depending of course who you support but AFAIK these are not being used to target civilians

[WilDun]

Not just the bad guys* - https://www.liquidpiston.com


*depending of course who you support but AFAIK these are not being used to target civilians

Yes well, we also have heard all the official replies from people in high places (from everywhere in the world) to controversial incidents such as these (the official replies usually go something like this :- "I seen no evidence to suggest that this is happening" - thus keeping the controversy going and buying time to destroy as much as possible (including people and their lives) - no regard or pity for anyone - none so blind as those who will not see!

Most people world wide, are ordinary decent people and we all love to see these engines being developed and want to see them succeed, they give us pleasure!
However, when a war comes along, all our endeavours are totally ignored, destroyed and of no consequence anymore (although still used for something evil)
It doesn't matter to those "dumb warriors" - they don't care who or what they are hitting and they don't care what or whose technology they are using to do so!

What an end to something good! - but then, mankind has been doing this forever (ie ever since we came into existence). - we were lucky and privileged to have been given a little window to pursue our own hobbies! - it hasn't always been like that!

I feel we are all pawns in the hands of just a few megalomaniacs!

[katinas]

[/COLOR]

....... we were lucky and privileged to have been given a little window to pursue our own hobbies! - it hasn't always been like that!......



Yes, absolutely agree. But we still have time, before the global confrontation between democracy and autocracy and new cold war will begin throughout the 21st century. The war in Ukraine may be just a prelude.

After using two-strokes for military drones, I wouldn't be surprised if we will see more horrible kamikaze drones with "echo" of V 1 pulsating engines in the near future. They can be cheaper and maybe lighter.
Add pdf "Valveless Pulsejet Engine" https://digitalcommons.calpoly.edu/cgi/viewcontent.cgi?article=1014&context=aerosp "The Kadenacy Effect was first discovered by the Dutch physical scientist Christiaan Huygens in the 1600s, but got its name from the physicist Michael Kadenacy who studied it in the 1930s. He found when studying two stroke
engines that the momentum of the exhaust gases leaving the cylinder will assist in the suction of fresh air into that
same cylinder."


https://en.wikipedia.org/wiki/Kawanishi_Maru_Ka10
https://www.bbc.com/news/world-middle-east-55229443
https://www.thedrive.com/the-war-zone/41263/air-force-finds-new-need-for-low-cost-engine-tech-used-on-nazi-buzz-bombs

So, return to my unfinished NS 250, with the cylinders from the very first Honda RS 250cc 1984 racer.

[husaberg]

Yes, absolutely agree. But we still have time, before the global confrontation between democracy and autocracy and new cold war will begin throughout the 21st century. The war in Ukraine may be just a prelude.

After using two-strokes for military drones, I wouldn't be surprised if we will see more horrible kamikaze drones with "echo" of V 1 pulsating engines in the near future. They can be cheaper and maybe lighter.
Add pdf "Valveless Pulsejet Engine" https://digitalcommons.calpoly.edu/cgi/viewcontent.cgi?article=1014&context=aerosp "The Kadenacy Effect was first discovered by the Dutch physical scientist Christiaan Huygens in the 1600s, but got its name from the physicist Michael Kadenacy who studied it in the 1930s. He found when studying two stroke
engines that the momentum of the exhaust gases leaving the cylinder will assist in the suction of fresh air into that
same cylinder."


https://en.wikipedia.org/wiki/Kawanishi_Maru_Ka10
https://www.bbc.com/news/world-middle-east-55229443
https://www.thedrive.com/the-war-zone/41263/air-force-finds-new-need-for-low-cost-engine-tech-used-on-nazi-buzz-bombs

So, return to my unfinished NS 250, with the cylinders from the very first Honda RS 250cc 1984 racer.

Is that a "Shorty PWK"of a Kawasaki KX or similar?
Tips his hat, your stuff is always so clean

[katinas]

Yes, one Keihin from YZ 250 03', second from RM 250 06'. Main difference between them, is position of PJ spraying tube. On YZ horizontal, RM slightly angled. I will try to adapt them to E85 , like before with Mikuni TMX. Very good results with E85.

But more interesting things, Husa. Finally, I accidentally found the most rarest and mysterious engine. I really knew it existed, but only found it now .
Kawasaki 250 cc racer (1989 code 009B, 1990 code 009C with double type KIPS ), from returning to GP program. Yes they used same intake concept like Honda, but cylinders banked at 75 degrees, like Honda started to use on NSR 250 two years later in 1992. Was only used in All Japaneses Championship, two years without better results. In 1991 they made radical upside down 250 cc X9, but this engine is well documented.

[husaberg]

That Kawasaki is very Honda looking right down to the sideways reeds.
Very detailed and neat clutch cover castings.
Very cool find

[Grumph]

The external positive stop mechanism is amusing. Similar system as used on a lot of Kawasakis - but they're usually indoors where they can be lubricated.
Spring loaded sliding plates, don't think they'd keep working well in a wet race. High maintenance.

[husaberg]

I never looked at the other side:laugh:
Its got a shit ton of webbing everywhere on the casings
Plus that clutch is as wide as the rest of the engine.

[katinas]

More pictures and with the bike, maybe someone will recognize who is on 76?

[husaberg]

More pictures and with the bike, maybe someone will recognize who is on 76?

AMA suggest a yank? he looks a little bit eddie lawson?

[F5 Dave]

Could be me from that picture. But it's not. (I'm the guy in the disco white pants).

[husaberg]

Could be me from that picture. But it's not. (I'm the guy in the disco white pants).

Well its not eddie as it 89 and 90....whoops
Doug Chandler?

[F5 Dave]

Actually I made a mistake too. That's not me in the white slacks.

I'm the three other guys in green overalls.

[husaberg]

Useless fact about AMA sticker in that era.
After this race 1990 Daytona Team Marlboro/Roberts withdrew from the AMA series in a dispute over placing a series sticker on the bike
Rich Oliver ended up racing the WERA Formula USA Series for the next couple of seasons as a result.

[katinas]

Sorry, just noticed now that 76 photo is later version 1991 1992, with upside down engine X 09. Dave, if your real name Trevor Crookes, it's you.
Trevor Crookes finished Daytona in 6 place, after very bad start. Kirk Hoeppner was AMA Kawasaki racer 89/90 in 250 class, but maybe on production KR 1.
Both engines V75 and upside down V90 had very low mid range, especially early V 75, that was main reason for poor results in 1989 1990 All Japanese Championship.

Very interesting article, but this is about V 90 upside down version. https://www.facebook.com/groups/1423373831228579/posts/1426543004244995/

[husaberg]

Sorry, just noticed now that 76 photo is later version 1991 1992, with upside down engine X 09. Dave, if your real name Trevor Crookes, it's you.
Trevor Crookes finished Daytona in 6 place, after very bad start. Kirk Hoeppner was AMA Kawasaki racer 89/90 in 250 class, but maybe on production KR 1.
Both engines V75 and upside down V90 had very low mid range, especially early V 75, that was main reason for poor results in 1989 1990 All Japanese Championship.

Very interesting article, but this is about V 90 upside down version. https://www.facebook.com/groups/1423373831228579/posts/1426543004244995/
Re Kirk Hoeppner
You could ask him about it

https://www.facebook.com/people/Kirk-Hoeppner/pfbid02grLLWuTGTohcud9MSjpt4SLXoHBYrXFmudvZvCDHBwZ H39EDb8bqbriJpAm8sGRvl/

found vis this
https://www.facebook.com/RiderFiles/photos/a.153854791325761/5555866184457901/?type=3

[katinas]

Thank you Husa, so many interesting black/white photos from 20 century.

[Grumph]

Got any details on the air-cooled single ? Thanks.

[katinas]

Got any details on the air-cooled single ? Thanks.

No idea, all photos from previous Husa reference to USA Facebook link.
Just can say that this carb is Amal. I have one special "methanol" type with large bowl. Add picture later.

[husaberg]

Got any details on the air-cooled single ? Thanks.

Its a Sachs engine if that helps
it has a cable rear disc
352700

i looks like the subframe has been lowered the rear loop almost looks RD/TZ

[husaberg]

Eddies 1981 factory KR250
note the rear sprocket and drive
Race on Sunday sell on Monday.
352701

[Grumph]

Its a Sachs engine if that helps
it has a cable rear disc


i looks like the subframe has been lowered the rear loop almost looks RD/TZ


Wallace identified the front half of the frame as road Suzuki T20/T250. Rear looks home made.

[katinas]

Eddies 1981 factory KR250
note the rear sprocket and drive
Race on Sunday sell on Monday.
352701

Belt drive, but slightly different.
Third photo, chain drive, but with huge rear brake disc.

[katinas]

Two-strokes that fell from the sky.
The Ukrainians tear down the engine from one of the downed Iranian kamikaze Shahed 136 drones, which the russian terrorists army attacks Ukrainian cities. They tries to identify the manufacturers of the parts. https://www.youtube.com/watch?v=OPDpaDJhi3U

[pete376403]

Two-strokes that fell from the sky.
The Ukrainians tear down the engine from one of the downed Iranian kamikaze Shahed 136 drones, which the russian terrorists army attacks Ukrainian cities. They tries to identify the manufacturers of the parts. https://www.youtube.com/watch?v=OPDpaDJhi3U

Lawnmower-level tech. But it only has to work for maybe an hour so maybe not even up to Briggs & Stratton / Tecumseh standard

[pete376403]

This is pretty...

[katinas]

Unbelievable holiday discovery in the beautiful mountainous area of Sardinia near Pedra Longa.
A lithographic quarry, called "Su Stabilimentu" opened in 1909 and operated until 1914​ and this engine was used to transport the extracted slabs of limestone by cable car to a dock, about 128 meters down.
One cylinder two stroke diesel engine with direct injection, two reed valves houses on the oposite sides on bottom of the crankcase for fresh air. Aluminium piston clear visible through transfer port, cooling intake pipe mounted under exhaust. Except numbers, the only possible identification logo is "GG" letters. I tried to ask the seller of the bookstore in Baunei town about the engine, but he only guessed that maybe it was German.

Indeed, sometimes strange things happen.

[F5 Dave]

Ahh, it will be a GasGas surely, they use that notation on their barrels:msn-wink:, heck my Trials bike does now I think of it.

[katinas]

Nice comparison, but similarity with Gas Gas only in letters. And interesting, that GG symbol casted only on the reed valves covers.
Add map of engine location if anyone travels here.

[F5 Dave]

That's the exhaust port, not that it makes a difference, and I was wrong about my trials bike. Just one G. Didn't dig my Enduro bike out of the dark for just a joke:rolleyes:

[katinas]

While looking for the GG engine, found interesting old books.
Magnesium powder and small pieces of silk for scavenging visualization.

[Pursang]

Oddball engine - amazing story!


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

[F5 Dave]

I watched that day before. Very Once over lightly.

Love Speed and Loss is a ore complete story, and then is the book Kim.

[katinas]

Interesting engine upgrades of EFI 2024 KTM 250. Brand new cylinder with reduced scavenging ducts.

[katinas]

Honda NSR 500 crankcase oil slots are arranged in an interesting way.
Crankcase coud be from 88 to 90 NSR 500 (or from 91 with different left side cover) as intake side studs placment is narrower and vertical reed cage position used before BigBang.

[husaberg]

Interesting is def an earlier version with the sideways intakes ala NSR250. Lawson ish period
Those orings in place of base gaskets seem like a bloody good idea.


354547
The later ones are very conventional.
354545354546354548354549

[katinas]

Earlier versions of 112 angle from 1987 to 1991, can be recognized by under engine water pump, unit crank and vertical side by side reed cages. Only 1990 model carbs positioned in skew way. But easiest way to recognize year is the engine left side gear cover, as they all different from 1987 to 1991 (89 and 90 just different colours).

[katinas]

Since 1991, an additional lower radiator has been used, but very ineresting that one of the Garder's 87 NSR 500 was equipped with additional radiator.

[pete376403]

Stolen from Facebook - Here's an engine rarely seen since they were intended to be disposable. This is the 4 cylinder radial engine from a WWII German G7A torpedo. It ran on Decaline fuel (decahydronaphthalene), which was first burned using compressed air (stored in a tank onboard) as an oxidizer. The combustion byproducts were then passed through a device called a 'wet heater', which also introduced water (from a 57L storage tank) to produce superheated steam. This high pressure mixture of superheated steam and compressed air was finally sent through the engine to drive the pistons.
Since the entire internal combustion/steam generator system was self-contained inside the hull of the torpedo, it could run underwater. The 4 cylinder, 'X' type radial engine produced up to 350 horsepower at its maximum power setting, which was enough to push the 26' (just over 7 meters) torpedo (the length of a large Uhaul moving van here in the States for comparison purposes) along at nearly 50mph while submerged.

[husaberg]

Around 90-91 Honda changed the crank from a 90 even fire to a two up two down this was to replicated the Yamaha .It made it more rideable this was later refined to firing all under 90 degees. ie big bang . 1992? The configuration Dohan returned to when he got bored after the unleaded fuel came in was the two up. the big bang needed a balance shaft af the engine was drove through the center to the jackshaft.
even when it was reverted the two up (ie screamer) they retained the balance shafted as it lessened the gyro making it turn easier. Not sure if this was the balance shaft or the fact it reversed the engine direction but likely both

[F5 Dave]

It sure sounded good from bottom of Lukey when he span it out of there. Marvellous stuff.

[husaberg]

edit it looks like pre big bang already had a jackshaft for reduced gyro.

[jato]

88 was the 90 degree firing - it had weird sound as you would expect. watching it exiting corners it seemed to give away a bike length or two compared to the 180 degree bikes (everyone else?) does anyone know for certain when the nsr first had a backward turning crank?

[katinas]

Not sure, but try to list in short way, just the main changes through the years, without obscured test models.

1981 - 1983 NS 500 V3 112 deg. symetrical 1-3-2 firing every 120 deg. - with long jackshaft, crank turning backward.

1984 NSR 500 V4 90 deg. symetrical 1-4-3-2 firing every 90 deg. - with long jackshaft, crank turning backward.

1985 - 1986 V 90 deg. symetrical 1-2-3-4 firing every 90 deg. - without jackshaft, crank turning forward.

1987-1989 V 112 deg. symetrical 1-4-3-2 firing every 90 deg. - with long jackshaft, crank turning backward.

1989/1990-1991 V 112 deg. symetrical paired 1.2-3.4 firing every 180 deg. - with long jackshaft, crank turning backward.

1992-1996 V 112 deg. big bang paired 1.3-2.4 firing 68 deg. two cranks connected to short jackshaft from center, crank turning backward.

1997-2002 V 112 deg symetrical paired 1.3-2.4 firing every 180 deg two cranks connected to short jackshaft from center, crank turning backward.

[katinas]

Stolen from Facebook - Here's an engine rarely seen since they were intended to be disposable. This is the 4 cylinder radial engine from a WWII German G7A torpedo. It ran on Decaline fuel (decahydronaphthalene), which was first burned using compressed air (stored in a tank onboard) as an oxidizer. The combustion byproducts were then passed through a device called a 'wet heater', which also introduced water (from a 57L storage tank) to produce superheated steam. This high pressure mixture of superheated steam and compressed air was finally sent through the engine to drive the pistons.
Since the entire internal combustion/steam generator system was self-contained inside the hull of the torpedo, it could run underwater. The 4 cylinder, 'X' type radial engine produced up to 350 horsepower at its maximum power setting, which was enough to push the 26' (just over 7 meters) torpedo (the length of a large Uhaul moving van here in the States for comparison purposes) along at nearly 50mph while submerged.

Found such old drawings of a torpedo engine. Very interesting two in one valve configuration

[Pursang]

Interesting engine upgrades of EFI 2024 KTM 250. Brand new cylinder with reduced scavenging ducts.

Perhaps trying to maximize bottom end power for stadium Superenduro ???

[katinas]

Perhaps trying to maximize bottom end power for stadium Superenduro ???

Everyone who tried it are very satisfied and yes much better througth rev range than older ones.

Upd. After 16 hours of run, piston ring snagging again. Very clear boundaries of piston dome color.

[Pursang]

Here is a video with some interesting moments (and a fair bit of Seppo Youtube Wankerism)

https://www.youtube.com/watch?v=LyI3KWMWbB4

Tip: watch without sound, pick through the bits with the viewing peaks.

Overview: 3D printed carbon fibre reinforced piston fitted in an old quad bike.

Test run: repeating slow U turns and accelerating, up to 42 mph.

Results: lasted 1min 30sec. Top ring separated and stuck in top of bore.

Melted crown, but skirt and gudgeon pin looks OK. (Go to minute 26).

My Take: Idea has some potential, if development and testing is done under controlled conditions.
eg, I think, at one point, some extra height was arbitrarily added to the crown. If it was detonating it would probably be quieter than usual.
Perhaps it needs an alloy insert to protect the crown and conduct some heat through the rings.
Different combinations of carbon and poly might be more heat resistant.
Perhaps oven/kiln baking to reduce the Poly and Set the carbon could work. Lots of ideas to investigate. Please let me know, when You get it right!

[ken seeber]

Firstly, I have to agree with your introduction words Dazza.

Irrespective of the clearances, profile and squish, a few things come to mind:

The ring groove. As the seat of the groove must be very flat and smooth for ring sealing, I’m not sure how good this could have been, direct off the printer. Despite being a flat surface in the X & Y directions of the print head, there is every chance for some waviness and minor projections. This means leakage = high temps = death.

From some views it looks like some form of ring anti-rotation is present. As they didn’t mention an actual pin, then one can assume that it was a printed projection at the base of the groove. This would prevent any lathe turning to smooth up the groove.

With the much lower thermal conductivity of the printed material being far less than aluminium, the crown surface temp would inevitable been very high. As the glass transition temp of even the highest temp printer materials is around 180C, there is the likelihood of bits just falling off, just as in the vid = death.

Not sure if they reamed out the piston pin bore and what form of retention was used.

It just shows that aluminium is pretty good stuff.

It also shows than many things can be made to work, it’s just a matter for how long.

Anyways it was interesting, to a point.

[katinas]

Long time ago, carbon piston was tested in small RC engine. Working fine, but after some time the piston deck starting to crush.
Add other carbon piston photos, first from Arctic Cat testing program.
.https://core.ac.uk/download/pdf/42785511.pdf

[R650R]

Stolen from Facebook - Here's an engine rarely seen since they were intended to be disposable. This is the 4 cylinder radial engine from a WWII German G7A torpedo. It ran on Decaline fuel (decahydronaphthalene), which was first burned using compressed air (stored in a tank onboard) as an oxidizer. The combustion byproducts were then passed through a device called a 'wet heater', which also introduced water (from a 57L storage tank) to produce superheated steam. This high pressure mixture of superheated steam and compressed air was finally sent through the engine to drive the pistons.
Since the entire internal combustion/steam generator system was self-contained inside the hull of the torpedo, it could run underwater. The 4 cylinder, 'X' type radial engine produced up to 350 horsepower at its maximum power setting, which was enough to push the 26' (just over 7 meters) torpedo (the length of a large Uhaul moving van here in the States for comparison purposes) along at nearly 50mph while submerged.

Very cool. This is probably where most of the “engines that run on water” prototypes start from. It’s a great idea in principle as steam is the single most efficient transfer of heat to mechanical energy. However no one can make a piston/cylinder combo that will last longer than the life of a torpedo run. Apparently the steam has a cavitation type corrosion going in this environment. For some reason maybe the larger bore sizes and slower speeds not such a problem for locomotives

[husaberg]

Classic motorcycle mechanics ran a story on a guy building engines in about 1982 84with the new then PEEK aka teflon
It had ceramic coated domes.
if I was doing one I would use MCM or plastic ceramic coated with sleeves to run the rings in

[pete376403]

No substitute for cubic inches - Nordberg two stroke radial startup

https://www.youtube.com/watch?v=u5p7GIJ9fz0

[Pursang]

https://www.youtube.com/watch?v=uMEegb-IrRQ

[lohring]

What a mechanical engineer's dream. Why they aren't investigating much simpler 2 strokes with their electric turbocharger is a mystery to me. Even a conventional 4 stroke combined with this turbocharger should allow a standard engine that can recover exhaust energy like was done in Formula I. The bottom line is that battery electric power is going to replace IC engines in cars and probably trucks, not because of government rules, but because they will last longer and are much less expensive to operate. I'm concerned that Chinese electric cars will destroy Germany's' car companies.

Electric cars haven't found their way into the popular consciousness yet since there aren't many electric cars on the road. As companies learn how to build electric vehicles the cost has come down to the cost of IC vehicles. Today I can buy a Tesla Model 3 performance version for close to half of what I paid in 2018. My car still runs well after 118,000 miles, saving over $2,000 a year in fuel costs alone. Its performance and handling is far better than any car I've owned in the past 60 years. The Supercharger network allows long trips even though Superchargers aren't as common as gas stations yet. Just got back from a 1,000 mile each way trip, and have gone on trips as long as 2,500 miles each way.

Pepsi has been running Tesla semis with very good results. The charging network is just starting to be built for these trucks. All this has been done over the last 12 years with little or no government help under an administration that can"t say Tesla, a company run by a very unpopular major stock holder.

Lohring Miller

[lohring]

https://autos.yahoo.com/fleet-operator-reveals-astonishing-performance-110057665.html

Lohring Miller

[katinas]

Some photos from The Italian Air Force Museum.
The piston cavities above the pin and one of the first piston opposed engines, 8 cylinders four stroke.

[Pursang]

A lot to like about this idea. Pretty Damn KISS!
It might be a '4 stroke' cycle but it is valveless!


https://www.youtube.com/watch?v=gi7IOXQ7oyo

[Pursang]

What a mechanical engineer's dream. Why they aren't investigating much simpler 2 strokes with their electric turbocharger is a mystery to me. Even a conventional 4 stroke combined with this turbocharger should allow a standard engine that can recover exhaust energy like was done in Formula I. The bottom line is that battery electric power is going to replace IC engines in cars and probably trucks, not because of government rules, but because they will last longer and are much less expensive to operate. I'm concerned that Chinese electric cars will destroy Germany's' car companies.

Electric cars haven't found their way into the popular consciousness yet since there aren't many electric cars on the road. As companies learn how to build electric vehicles the cost has come down to the cost of IC vehicles. Today I can buy a Tesla Model 3 performance version for close to half of what I paid in 2018. My car still runs well after 118,000 miles, saving over $2,000 a year in fuel costs alone. Its performance and handling is far better than any car I've owned in the past 60 years. The Supercharger network allows long trips even though Superchargers aren't as common as gas stations yet. Just got back from a 1,000 mile each way trip, and have gone on trips as long as 2,500 miles each way.

Pepsi has been running Tesla semis with very good results. The charging network is just starting to be built for these trucks. All this has been done over the last 12 years with little or no government help under an administration that can"t say Tesla, a company run by a very unpopular major stock holder.

Lohring Miller

In Kiwi Biker Land we tend to have a preference for the max HP option. High volume manufacturers are subjected to increasingly strict emissions regulations and must comply, to stay in business. A little, additional, but basic, mechanical complexity that reduces emissions and still maintains a high performance output is worth investigating.

[lohring]

According to a friend who worked first at Eco Motors on electric turbos and now works on this project (https://www.garrettmotion.com/news/newsroom/article/what-is-an-electric-turbocharger/), Porsche is considering this technology (https://newsroom.porsche.com/en/2024/products/porsche-new-911-world-premiere-hybrid-36322.html) as well. I think it would be an even better solution for two stroke diesels like the Achetes opposed piston engine. Running on hydrogen their engine would have essentially zero emissions.

Lohring Miller

[Pursang]

Here is another, more independent, look at the Omega engine.
Better idea of the operation and some plus & minuses.


https://www.youtube.com/watch?v=pgQSCFRPac4

[lohring]

Good luck with sealing. There's a reason round pistons in round bores are used in all successful steam and IC engines. It's easy to get a good seal even when the parts are made by early, low precision machines. Fancy engines, even with modern machines and materials, have always stumbled on the sealing issue.

Lohring Miller

[ken seeber]

Good luck with sealing. There's a reason round pistons in round bores are used in all successful steam and IC engines. It's easy to get a good seal even when the parts are made by early, low precision machines. Fancy engines, even with modern machines and materials, have always stumbled on the sealing issue.

Lohring Miller

Have to agree with Lohring. I worked on the Sarich Orbital engine in the mid 70s. It became clear after some time that there were fundamental issues with this engine, ultimately leading to the two fluid (air and fuel) fuel injector and its application to various engine applications. The 4 main key faults of the engine, which can be seen on the many new IC engine concepts are:

1. The total seal grid length of anything other than a round piston can me many times longer friction
2. Any square corners are very, very difficult to seal = leakage
3. Any combustion shape that has large squish areas will suffer from "quenching" of the combustion flame = inefficiency & unburnt HCs.
4. Any combustion shape that departs from being spherical means a high surface area to volume ratio = heat loss = inefficiency.

For me, it is 2 strokes and after that it is electricity. Interesting that many companies are now dropping the "green hydrogen" concepts, particularly combustion, and going electric & batteries. Here's my perspective as to why:

355062

Sorry, bit of a rave...

[lohring]

We're getting way off topic. It's very hard to beat the modern two stroke for compact IC engine power. Two strokes dominate the small and large engine areas. They suffer from breathing issues so more complex four strokes have taken over in the middle sizes. Honda especially has perfected the small four stroke and gas turbines have taken over all but the very largest IC engine sizes.

However, even gas turbine mechanical simplicity can't beat an electric power plant. Mobile electric power has been limited by battery technology from the beginning. Stationary electric motors dominate everywhere there is an easy electricity connection. Electric motors have very long lives, even in inexpensive versions. We are in an era of exploding (not literally with proper design and care) battery technology. This is starting to make electric power popular in the small to medium size mobile power areas.

In my sphere of radio control racing, 26 to 36 cc two strokes still dominate, but electric power has replaced IC in many non racing model airplanes and boats. It's slowly expanding into race boats. I have loved small two strokes since before I built one in high school shop. I still love them as high power racing engines. We'll see how long they last.

Lohring Miller

[Pursang]

...
We don't need no 'Stinking Chambers'......the Bloohie pipe lives


https://www.youtube.com/shorts/fIGne6fW8mE

[katinas]

Not sure, but try to list in short way, just the main changes through the years, without obscured test models.

1981 - 1983 NS 500 V3 112 deg. symetrical 1-3-2 firing every 120 deg. - with long jackshaft, crank turning backward.

1984 NSR 500 V4 90 deg. symetrical 1-4-3-2 firing every 90 deg. - with long jackshaft, crank turning backward.

1985 - 1986 V 90 deg. symetrical 1-2-3-4 firing every 90 deg. - without jackshaft, crank turning forward.

1987-1989 V 112 deg. symetrical 1-4-3-2 firing every 90 deg. - with long jackshaft, crank turning backward.

1989/1990-1991 V 112 deg. symetrical paired 1.2-3.4 firing every 180 deg. - with long jackshaft, crank turning backward.

1992-1995 V 112 deg. big bang paired 1.3-2.4 firing 68 deg. one piece crankshaft connected to short jackshaft from center, crank turning backward.

1996 V 112 deg. big bang paired 1.3-2.4 firing 68 deg. two cranks connected to short jackshaft from center, crank turning backward.

1997-2002 V 112 deg symetrical paired 1.3-2.4 firing every 180 deg two cranks connected to short jackshaft from center, crank turning backward.

The last two "Racers" issues are dedicated to GP two-strokes, YZR 250 vol.74 and NSR 500 vol.75.
I must correct my previous post about the NSR 500 crankshaft from 1992 to 1995. It was a one-piece crankshaft, with a central gear and a short jackshaft. Two pieces crank was used from 1996. Looks like central gears made like one piece with center pin.
In general, a lot of interesting material. The NSR 500 crankshaft absolutely piece of art.

Third picture, reed valves from early versions of 112 deg. NSR 500

[husaberg]

This does raise and interesting (well to me anyway) question For Mr Thiel if he's about. Plus Mr Overmars
Given the rules of he period for the GP500 class hat layout and engine configuration would he have chosen
l always admired focused output ideal with the single crank and liked the room for intakes and transfers with the single crank and balance shaft set up.
Especially;;y Compared to the Twin crank set ups.
But would they have gone twin crank and Disc valve "V four" twin, 3 ? stepped Square?

[katinas]

The balancer weights are very interestingly arranged on the intermediate shaft. I marked them with three arrows.
Looks like this is 1993 model with additional fuel pump for the EFI system.

Some Interesting disclosure from Honda engineers.
From 1994 to 1999 there were 5 different crankshaft pins phase tested. In addition to the two main ones ( 68 degree and 180 degree), three more were tested
A. 90-degree equal interval explosion (like 88 89)each crank pins phased 0-22-180-202 deg. tested in 1998.
B. 90-degree Big Bang crank pins pairs set at 22 deg.
C. 112-degree explosion, all crank pins set in line

[F5 Dave]

This does raise and interesting (well to me anyway) question For Mr Thiel if he's about. Plus Mr Overmars
Given the rules of he period for the GP500 class hat layout and engine configuration would he have chosen
l always admired focused output ideal with the single crank and liked the room for intakes and transfers with the single crank and balance shaft set up.
Especially;;y Compared to the Twin crank set ups.
But would they have gone twin crank and Disc valve "V four" twin, 3 ? stepped Square?
My gues is; only if the tracks were longer with less of those pesky corners. Maybe 2025 tyres could have altered the formula. . .

[katinas]

A few photos of Honda RS/NS 500. 1985 looks more like NS.

https://www.ebay.co.uk/itm/306230838147?_trkparms
https://www.ebay.co.uk/itm/306230838044?_trkparms

[Pursang]

Here is an interesting video on a 3cyl with an unusual configuration.

Made in Oz, exported to the USA.

Not a two stroke, sorry.


https://www.youtube.com/watch?v=80Mifwt1zz8

[Pursang]

Looks Good!


https://www.youtube.com/watch?v=5czHDU6pK8E

[F5 Dave]

So, ahh, what lubricants the top end?
I smell a rat.
Also power claims are tremendous.

[diesel pig]

So, ahh, what lubricants the top end?
I smell a rat.
Also power claims are tremendous.

I would have to agree. I don't know how much oil compression rings need but it is not none at all.

[lohring]

All the issues mentioned were solved in the last century by Junkers' opposed piston two strokes. They were aircraft engines which need both light weight and fuel efficiency. Today if you add an electric turbocharger (https://www.garrettmotion.com/news/newsroom/article/what-is-an-electric-turbocharger/) that can provide starting and idle air flow, you get even better power to weight since the compressor won't need engine power at maximum output. In any case no large manufacturers of medium to small IC engines is going to put lots of money into a technology that's being replaced by electric power.

Lohring Miller

[katinas]

Very similar to an old Swiss "Sulzer" marine two stroke turbo engine.