Re: Bicycle Engine
lol, guys VVT has been around since the 90s. Almost all new vehicles now are using some form of vvt that will adjust the valve timing of the engine based on rpm. The aggressiveness of the variable valve timing will determine how much of a kick you notice in the higher rpms.
As for two strokes vs four strokes: it is what it is imo. They both have their applications. I am almost ready to fire up my 66 cc chinese bike kit engine and I have ported out the chug and flushed out the crankcase with wd 40 then engine oil. I would highly recommend you flush the crankcase on a new engine just based on how filthy the first bath of wd40 came out.
I dont know if any of you guys are into boating, however right now out of all the new outboard boat motors being manufactured, the evinrude etec advanced 2 strokes are the best choice for a power plant for your boat imo. Look up evinrude etec technology. Basically it uses the 2 stroke cycle, however it is a direct injected two stroke. The engine has an ecu computer that wont inject the fuel until the piston has traveled up enough to close of the intake and exhaust ports. It basically acts like a 4 stroke when both valves are closed. It can also control when it injects the fuel in the stroke so that it can inject less of it later at lower rpms to only use a smaller displacement of the cylinder, saving fuel. Its a really amazing motor and i strongly recommend you google it if you are interested in innovative motors and mechanics. If I were to buy a boat motor right now to repower my 1973 fifteen foot chrysler tri hull boat, my first pick would be and Evinrude Etex, but if I had to go with a fourstroke I would look at either a Mercury EFI, or a Honda.
anyways thats my contribution to this debate.