Need help asap - Thermal Efficiency of a Two Stroke Engine
 

Hi guys,

I would just like to find out what the thermal efficiency, TE, of a typical model engine is. (TE = ratio of heat converted into work compared to heat recieved). I know that in a 4-stroke gasoline engine the TE is approx 30%.

i.e. Normal, low compression car -> .26
Racing Car -> .34

What kind of number should I expect from a model engine. This is really important for me as i need to now this as soon as possible for my professor. Are they more or less efficient than a typical two stroke engine??

Thanks,
UCC

Need help asap - Thermal Efficiency of a Two Stroke Engine
 

Ha. Good luck. Try this: Typical fuel consumption in oz/min= displacement in 1*cid. So, 1.0 cubic inches = 1 oz/min. AND, typical power in Hp = 2*cid. So, 1.0 cubic inch = 2 hp.

So we have 2 Hp at 1 oz/min methanol. This is not at peak operating condition, rather, at normal "flight load" conditions. You'll have to calculate the heat value of methanol.