ESE's works engine tuner

[WilDun]

If pistons are flat, no need for overlap...but good thinking, if any other kind of dome,higher compression ratios are not achievable.

I never think domes with opposed piston, Especially if it's HCCI. ..... It was just a mental exercise really, not to be taken as a new invention! nor for anyone to think that I was contemplating doing it! - I like thinking about and exploring all the different scenarios, (most of them possibly not viable!) - but with no real workshop or a place to have one anymore, none of the stuff I dream about will ever come to fruition - guess being a thinker only, is not enough! - gotta be a doer!

BTW, hope you don't mind me asking - would you consider yourself Croatian? or Dalmation? - Many people in New Zealand have Dalmatian ancestors.

[Frits Overmars]

I thought Duckworth was a far seeing man, but he didn't consider the two stroke or turbos...

Oh yes, he did. He proposed a Formula 1 two-stroke engine with a huge compound turbo and a huge exhaust timing, so the combustion engine would in practice serve as a combustion chamber for the turbine that would drive the wheels. The advantage over a conventional gas turbine would be that the combustion takes place intermittently at a higher pressure. The higher pressure would ensure a better thermal efficiency and the intermittent character would reduce the thermal load, keeping the engine parts from melting (no ceramics to speak of available back then).
At the same time Duckworth proposed a restricted fuel regime instead of the cylinder capacity regime. In other words: "Here is your 100 liters of fuel and you can do with it whatever you want".

[WilDun]

Oh yes, he did. He proposed a Formula 1 two-stroke engine with a huge compound turbo and a huge exhaust timing,................
At the same time Duckworth proposed a restricted fuel regime instead of the cylinder capacity regime. In other words: "here is your 100 liters of fuel and you can do with it what you want".

Frits,
Well, there you go! - that news restores my faith in him - I had always heard that he was a great man, but I guess I didn't dig deep enough!
On the other hand, I have heard a few things about Chapman which weren't terribly complimentary though!

Has anyone ever tried using the Wankel layout for a blower (possibly even without seals, as in the Roots type supercharger?).

[Pursang]

Hi Folke.
I am a faithful defender of the basis of its principles, but I disagree in the form.
I don't understand why it needs to be. "Having a solid seal on the exhaust valve will allow additional inlet pressure to be added and will also prevent the fresh fuel mixture from escaping."
I do not see the need for the "theoretical plug" to have to be SOLID (an example: neither is it necessary to have a deflator to direct the load upwards) you only have to orient the jets properly).
I may be wrong wrong about the ways, but the important thing is to show that the principles are appropriate and in that I see that you are fighting to achieve it

Perhaps a variation on the COMPREX supercharger principle could provide a valveless seal/plug in the exhaust duct, phased to rpm (and a pressurised charge).




cheers, Daryl

[Frits Overmars]

Has anyone ever tried using the Wankel layout for a blower (possibly even without seals, as in the Roots type supercharger?).

Yes, there are multiple examples of it. The first may have been NSU (who else?) , supercharging the piston engines in some of their land speed record machines.
Rolls Royce went one better: they used a Wankel blower to supercharge their Wankel diesel, and drove that same blower with the diesel's exhaust gases, much like a turbocharger.

[Philski]

Hi all. Thank you all so much for blowing my mind so often. Artificial intelligence variable valves. omg. um. I was just wondering if anyone has seen a tesla turbine on a bike? I was thinking of a tesla crank web to help pull fresh charge in.

[lohring]

The common screw type (Lysholm) compressor has a lot of advantages for small engine superchargers. It can generate high pressure efficiently at engine rpm. You would still need to supply back pressure to keep the mixture in the cylinder. That's the reason turbos are a good idea. You can set up the whole system so most of the power comes from either the engine or the turbine. All this was known and tested a very long time ago. One of the most efficient engines developed with these principles was the Napier Nomad. More successful was the Wright R-3350 turbocompound engine. Both were stopgaps until efficient turbines were developed. Detroit Diesel built a series of successful both naturally aspirated and turbocharged two strokes from 1938 to 1997. Today snowmobiles are the main user of turbocharged two strokes. Modern turbos are available at low cost in very small sizes. They should work very well with two strokes as small as 50 cc.

Lohring Miller

[lohring]

Note that the Detroit Diesel engine could be configured as a constant power engine. That gave it the performance characteristics of steam engines and electric motors. Truckers especially appreciate this characteristic.

Lohring Miller

[ceci]

Can you tell me some 4S engine that uses piston pump supercharging.
At 2S we all know that they were serially produced by a certain brand and for a few decades

[WilDun]

Can you tell me some 4S engine that uses piston pump supercharging.
At 2S we all know that they were serially produced by a certain brand and for a few decades

This probably doesn't really help in answering your question of course! .... but the piston type compressor was used on quite a few successful two stroke engines based on (relying on my memory here) Ricardo's "Dolphin" V2 layout ie Power cylinder/compressor cylinder arranged as a V twin) this engine appeared around 100 years ago, and I think was also used in fishing boats.

https://www.kiwibiker.co.nz/forums/a...4&d=1586821782


This layout was also used successfully in the Trojan light delivery truck in Britain - I think a V4 - it also used 'split single' layout) - however, basically the Dolphin layout).

https://www.kiwibiker.co.nz/forums/a...5&d=1586821791

Then of course there was the DKW racer which was raced in pre war, pre-expansion chamber days and which (reputedly) shattered windows all round the IOM TT circuit! - it used the 'split single' arrangement and a piston type supercharger.

(DKW)

(Montesa)

(Motobecane)

Another interesting site :- https://www.elsberg-tuning.dk/supercharging.html

[Muciek]

Rg250 turbo from back in the day.

[Flettner]

Is this turning into the odd ball engines thread? If so.

My uniflow engine has ended up 295mm crank center to crank center, 48 stroke on each, 100mm long rods. Not as bad as it could have been. Normally I build my uniflows with a split in the middle between the cylinders but this time Im having a go at casting the whole cylinder as one. With lugs cast in for sparkplugs, or whatever, or not at all. Three lugs at 120 degrees with water flow right over the lugs. Same size pistons this time so the bore can be bored, nikasil finished easily. Six transfers, three from each crankcase, four exhaust ports. In house manufactured pistons, or should that read round the back of the house. The plan is to still run tuned pipes and a kind of powervalve setup, blocking off two of the ports at low speed? Possibly some on the fly timing changes between the cranks? Many possibilities.

[WilDun]

Note that the Detroit Diesel engine could be configured as a constant power engine. That gave it the performance characteristics of steam engines and electric motors. Truckers especially appreciate this characteristic.

Lohring Miller

Yes, it's probably worth looking at these types of layout - but we took a wrong turn way back in the sixties and opted for high revving top end power instead - mistake! - we were all guilty!

[WilDun]

Is this turning into the odd ball engines thread? If so.

My uniflow engine has ended up 295mm crank center to crank center, 48 stroke on each, 100mm long rods. Not as bad as it could have been. Normally I build my uniflows with a split in the middle between the cylinders but this time Im having a go at casting the whole cylinder as one. With lugs cast in for sparkplugs, or whatever, or not at all. Three lugs at 120 degrees with water flow right over the lugs. Same size pistons this time so the bore can be bored, nikasil finished easily. Six transfers, three from each crankcase, four exhaust ports. In house manufactured pistons, or should that read round the back of the house. The plan is to still run tuned pipes and a kind of powervalve setup, blocking off two of the ports at low speed? Possibly some on the fly timing changes between the cranks? Many possibilities.

Just look on it as "helping ESE out" because of buckets not being allowed out to play these days! - I do hope TZ sees it that way! - reckon "Oddball" will get this sort of stuff back again one day! - that's why it started anyway - to relieve the congestion here at ESE!!

Your scheme sounds good so far - lots of future variations and possibilities available and above all, some concrete evidence ( as opposed to all the wild theories we have been chucking around!). .... I'm a little biased of course, but just do it I reckon!

[Flettner]

Or perhaps three exhaust ports, block two off at low revs then one, and then none at high revs. Three small pipes of varying lengths with little flaps in them to make them the same short lenght at high speed, mmmm.