I'm trying to install canisters into an existing plane that has a canister tunnel..Problem is that that the tunnel is to short to accommodate the header and the MTW 75 canister length supplied by DA..Not impossible but i really don't want to change the tunnel that's there.

So i'm wonering what the consequences would be if i shortened the 10.5" headers by 5"??? Or is it a must that the headers be that length.

Thanks Jack

The MTW canisters are tuned. That means, that performance will suffer when you shorten them. Best length for performance around 7000 rpm is 10" Any shorter than that, and engine running will become harsher and less smooth.

Thanks Pe, I somehow knew it would be wise not to do it

Jack

You could install a set a BMB canisters. They are tuned for short headers 3'' to 4'' headers and DA is dealer un USA/Canada. I had good results on DA-50.

http://www.desertaircraft.com/page.php?Page=BMB

Get as big a JMB can as you can fit in the plane and run the header as short as you want..

The JMB however is rather restrictive. I also had ~50°F higher cylinder temperatures, as compared to MTW.

All a compromise - I detest peaky, balky exhaust setups

I do not Dick. All things have their pro and contra. If you find out which is which, you can use that knowledge to make the most of it considering your needs of the moment.