I posted this on Modifications but did not get any advice so I will repost here in hopes that some engine expert will see it. I have a C-90 that is in overhaul. My engine guy told me that the exhaust was not properly built. It is a J-3 style and the pipe after the rear cyl on each side continues to be 1.5" dia i.e. the dia. does not increase as the rear cylinder's exhaust joins. He says it should be a bigger dia. than the stacks coming off the jug i.e. it should go up to 1.75" or 2" from 1.5". He believes having the same dia. downstream of the 2nd cylinder is creating back pressure and robbing me of power. Can anyone confirm/deny this? What should the pipe dia. be after the 2nd collector - 1.75" or 2"? See my post on the modification thread for pictures.
thanks for any advice
thanks for any advice
thanks for any advice
thanks for any advice
