Hi all,

I read this thread about glow engines and gas engines, as glow engines have glow plugs, gas engines have spark plugs which I have seen being used in cars or in motorbikes, and gas engines are run by gasoline, am i right or wrong. I have seen higher displacement glow engines as well as lower, so are the gas engines. I have a question, that when the displacement or CC/CI inreases rpm decreases, the smaller the engine more the rpm. Does higher rpm make a difference in engine's performance, and can it take plane to a vertical climb up? or the gas engines with low rpms they have more power?. Why the rpm decreases when the size of engine increases?

Thanks

Mody