2 stroke thread (with occasional F1 relevance!)

[autogyro]

Here is another ( current) example of a smooth running 2-stroke aero-mill..

http://www.zoche.de/

Very nice and worth trying.
We did experiment with LPG as a fuel at one time.
Partly because aviation fuel was getting so expensive but mainly to use the tip jet VTOL system I had been working on.
We even sourced an auto-clave and were working on the manufacture of carbon fibre pressure fuel tanks.
Trials were to be undertaken in a Piper with the wing tanks replaced.
All the pre-flight tests were positive.

[J.A.W.]

Actually A-G, if you care to check the facts - viz read the ~20yo NASA report which details the Garrett ICE helicopter
mill study ( high efficiency 2T turbo-compound-diesel good for 2.2Ltr/1000hp), you will have to concede that
U-F, is of course - quite correct - in his emphatic assertions..

Of course he is correct the data he used was also correct.
However outright power to weight is not the main issue with a light aircraft engine.
Turbo compounds of 2.2 litres per 1000hp are hardly worth considering.

a 2.2Ltr/1000hp 2T - is in fact - directly relevant to this thread.. ..surely..

[autogyro]

http://en.wikipedia.org/wiki/Rolls-Royce_Crecy

In which case this is also relevant to the thread.

[J.A.W.]

I understand Ricardo still has some of the R-R Crecy test-cylinder clips on hand, A-G, it'd be cool to check 'em out..
I wonder if any footage of the full 12cyl beast running still exists, that would be something to see/hear..

[uniflow]

Autogyro, this is probably not the forum to be talking about Autogyro's, Lets continue this conversation at http://www.pra.org a real autogyro forum. You may even learn somthing of the modern gyros available today, I know I have.

R.A.W , yes there must be original film of at least one of the Crecy's run. I do belive it would be music to the ear!
On the subject of noise it is interesting to note that in modern motorcross the fourstroke engines are by far the worst at noise production. The twostroke by way of useing the exhaust pulses to to do charging work, lets a lot less exhaust energy out to atmosphere, quieter. How times change. And with power valve gates in the exhaust used mostly now, less noise at lower speeds, also much wider and more useful power curves (and less fuel wasted out the exhaust). Way more useful for lite aviation than they ever have been in the past.

[J.A.W.]

Sound frequencies have a bit to do with it too, U-F,
& it was interesting that FIM had to relax the sound level rules which would've cruelled Moto GP 4T outputs..

My pick of the Moto GP 4Ts sound-wise was the Aprilia Cube triple, I heard that live @ Phillip Is, it was ..LOUD..
..but with that harmonious even firing 120` 'musical' quality.. ..that I'm sure your 2T triple puts out too..

Ironic that F1 never had any noise issues, 'cept ironically, with the new turbo units dulling it..

[FW17]

2 Stroke Petrol has a few limitations hence not commercially viable for cars and bikes on road but the same cannot be said about 2 stroke diesels.

2 stroke diesels can be up have up to 20% more power 40% ore torque, lighter and yet be less pollutant than the 4 stroke, so why has there been no major studies on this? why no Audi LMP 2 stroke engine?

[Cold Fussion]

2 Stroke Petrol has a few limitations hence not commercially viable for cars and bikes on road but the same cannot be said about 2 stroke diesels.

2 stroke diesels can be up have up to 20% more power 40% ore torque, lighter and yet be less pollutant than the 4 stroke, so why has there been no major studies on this? why no Audi LMP 2 stroke engine?

Would it not be in the rules mandating a four stroke engine?

[FW17]

Would it not be in the rules mandating a four stroke engine?

LMP is quiet open, if a manufacturer is interested in making a 2 stroke to compete in LMP then they would rewrite the rules accordingly

This was quiet impressive

[olefud]

2 Stroke Petrol has a few limitations hence not commercially viable for cars and bikes on road but the same cannot be said about 2 stroke diesels.

2 stroke diesels can be up have up to 20% more power 40% ore torque, lighter and yet be less pollutant than the 4 stroke, so why has there been no major studies on this? why no Audi LMP 2 stroke engine?

Perhaps more to the point, why no Detroit diesel –out of production for maybe 15 years now.

[J.A.W.]

Good points..
As for "commercial viability"..
.. certainly one of the complaints of the sports operators of competition motorcycles re: SI 2Ts being 'ruled' out,
is the greatly increased cost involved in 4T consumables, - check the complexity of components above the piston..

Maybe good "commercial viability" for the makers spare parts dept.. .. but not so good for the operator..

& even on a 'green' basis, the significantly greater cost/usage of resources/processes in manufacture of complex 4Ts
needs to be taken into account..

[J.A.W.]

As recently posted in the "IMAGE" thread,( & where collateral discussion is verboten, apparently),
- here is a wild 2-stroke GP racer from ~80 years back.. ..16cyl, blown 2-row radial & FWD..

http://www.oldmachinepress.com/2012/09/ ... co-trossi/

Paired cylinders ( one head/combustion chamber per co-firing pair).. so..8 banks of 2, or 2 banks of 8?

[uniflow]

I imagine its eight split singles all bolted together. Supercharger does the job the crank case normally does?

[autogyro]

As recently posted in the "IMAGE" thread,( & where collateral discussion is verboten, apparently),
- here is a wild 2-stroke GP racer from ~80 years back.. ..16cyl, blown 2-row radial & FWD..

http://www.oldmachinepress.com/2012/09/ ... co-trossi/

Paired cylinders ( one head/combustion chamber per co-firing pair).. so..8 banks of 2, or 2 banks of 8?

I love through scavenged two strokes, either this way or opposed piston.

[J.A.W.]

This following vid shows the addition of a turbo pumping ~1bar boost to a regular 125cc production 2T allows..
..a peak power output ~equivalent to the best N/A pursang G.P.125 bikes..

http://www.youtube.com/watch?v=Oxj_OAb5bqk