Why do we need a prop before running it.

[Bavafa]

I was wondering just out of curiosity, what is the reason that we need to have a prop or fly wheel on an engine to run them. What could be caused and why in the absent of one.

Thanks in advance
Mehrdad
RV7A

[jsharkey]

A fly wheel or prop or "club" in the case of an aircraft engine helps smooth out the individual torque pulses generated when each cylinder fires. With out enough rotational mass to absorb these pulses the engine would probably shake itself to pieces - and anything else that it was attached to.
Jim Sharkey

[N941WR]

Mehrdad,

This question came up a few months back but I couldn't find the thread. Mel, can you find it?

There was some really good info on that thread.

[sakhurst]

I think this might be the one you were searching for:

http://www.vansairforce.com/communit...ght=dummy+prop