What size pipe should be used for headers?  I assume it will be 321 stainless. Wall size?  Thanks for any help.

 

Joe Berki

Limo EZ

Just a bit bigger ID than the exhaust liner exit hole. The rules of thumb are: (depends on your engine) 1 7/8" ID or 2" ID in .062" stainless or .125" wall mild steel. As large a radius as is possible on bends. Primary lengths in multiples of 10" to 12". Both primary tubes exactly the same length. A flex joint of some sort to allow for engine movement. Otherwise the whole system must be mounted rigid to the engine and properly supported. The lowest back pressure muffler possible.

 

Do not wrap mild steel with insulating tape. The steel will decompose and blow out the outside of the bends (where it is thinnest). 

 

The engines are 4 strokes but tune like piston port 2 cycles. So, exhaust design makes a big power difference.

 

Lynn E. Hanover