What is the minimum exhaust length?

[acny]

Hi,

I'm using my 160 in the thick woods/brush and was hitting and bending my upright exhaust so I shortened it to about 15" high from the manifold. This works well in the woods but I wonder if it is long enough to keep the cool air from warping the valves. I tried a bottom exhaust but that gets hung up in minutes.
Thanks,
WM

 

[Bob]

Don't worry about it.

The whole "short exhaust = cold air = warped valves is 98.6% horsepuckey.

The only time I'd even consider believing that old mechanics wive's tale is if you were to pull it 'til the exhaust was red hot, then shut it down with no idle/cooldown period. Even then, I doubt if there'd be a problem.

 

[old]

As Bob say. Ya if you ran one with out the manifold ya you might have a problem with the valves but that is about the only way. If you think about it as long as the engine is running there is no way for cold air to get in to the valves since the engine is always blowing out from the exhaust

 

[acny]

Thanks, I don't think I'll worry about it then. Actually its more like 2 feet long anyway. Just a few inches higher than the loader frame.

Have a good one,
WM