It seems that if the pipe is able to carry the hot gases from a single cylinder's pulses it could carry the pulses of any number of cylinders as long as no two pulses come at the same time and it doesn't slow down. If it is put into a larger pipe and allowed to expand it will slow down and the train behind it will rear end it. Then the trains start piling up all the way back to the cylinders. This is a great thread. I am getting ready to build headers for the 4 cylinder. Beater
