DaveR
I'm sure the technical difficulties are daunting, but what choice does YS really have? If YS wants to continue in the model engine market, they better figure out how to make a gas engine in the next few years, or they will be bankrupt and without a market like Kodak.
Can it be done by YS to produce an equal powerful engine running on petrol with the same physical dimentions as theirs methanol/mix engines? I do not think so, but if they do it, horray I was wrong.
I will try to substansiate the above. (Some math will be necessary to explain this)
2 and 4 stroke engines.
4 stroke Volume svept= n cylinders x pi/4xbore sq x lenght stroke
2 stroke, if the exhaust port closes some distance before tdc (top dead centre) then the trapped svept volume is:
2 stroke Volume trapped = n cylinders x pi/4 x bore sq x lenght stroke
This volumes can produce the work:
2 stroke Work indicated = imep x volume svept x rps
4 stroke Work indicated = imep x volume svept x rps/2
(imep = Indicated mean effective pressure)
(rps =revolutions per second)
Interpretation of the last one. A 4 stroke engine of equal power of the two stroke (Work indicated), with equal svept volume must have an imep value that is double of the two stroke engine. One can play with these three factors but the end result should be the same. Question, how practical will it be with a 4 stroker reving 16-20'?
I hope this will help to understand why i donot think a 4 stroke petrol engine will be as powerful as a methanol/mix engine compared as apple to apple. YS can make their engine more powerful by increasing svept volume and so on but that will be a totally different engine.
The YS 4 stroker really is a fantastic powerful engine running on methanol/mix. The CDI has the advantage that it donot need a lot of fuel to correct the ignition timing as glow need.
Hope I did not offended someone.
Best regards