Why don't they put bike engines in cars?

ha yeah how long before you ended up upside down though

Some people do put bike engines into cars. Check out these videos for a laugh http://uk.youtube.com/results?search...&aq=1&oq=smart

And the reverse is not a problem if you want to build a decent one. A reliable reversing box like this works well http://www.rallydesign.co.uk/advance...enlqrle1324vt2

http://uk.youtube.com/watch?v=mnfxG4...eature=related this is a funny little one

[Sid Squid]

Originally Posted by Flamin_Squirrel

Not enough torque, I'd imagine.

Quite, the demands made of the engine by a bike and a car are quite different, thus the designs are very different.

Originally Posted by G

And to be fair its much of a muchness.......an engine is an engine.

Not so, not by a long, long way. Cars require torque such that they can carry lots of bodywork around, this means a very different approach to engineering the motor.

Originally Posted by G

Putting a 600cc engine in a 1ton car is pointless.

Why? If it were suitably designed it would work fine, obviously at that capacity and weight it's never going to be a performer, but there's no reason why not.

Originally Posted by Stu

Why does no one put a car engine in a bike?

Been done many times. But for specific needs, as above - build, (or choose), the motor that features what you need.

Originally Posted by yorkie_chris

Car engines tend to have longer stroke and milder cams for torque. Also helps economy.

Very true.

There's no such thing as 'right', what do you need your engine to do? It's design will need to take account of that, bike and car engines are very different nowadays. Our bikes have heavily over-square designs, that keep peak piston speeds within the materials acceptable limits, car engines typically have the opposite so their volumetric efficiency, (thus BMEP), is spread across a wider portion of the speed range, typically they will have smaller valves too, this keeps gas speeds high so VE is preserved too.

[Mr Speirs]

Check it:

http://www.zcars.org.uk/mini/index.htm