Oddball engines and prototypes

[Frits Overmars]

Attachment 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]

Attachment 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/wik...-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!

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=wa...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/2015/07/0...-tales-galore/

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

[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....

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!!

[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.

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

[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

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?



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.