Originally posted by eddiethefish
I run RB Rody X12 5-Port and still slower than compaqboy's on the straight. My gearing is right, but just not any faster...
come to think of it, 5 supposed to be faster than 3 on the straight, but it isn't!
Depends on too many factors. Head clearance, nitro %, pipe and pipe length, timing, length of the straight etc.
With the correct set up a 3-port will match any 5-port for power. Technically, any engine only has 3 main ports and an exhaust port. What the manufacturers refer to as a 5/7/8 port etc engine is just taking the 3 main ports and splitting them up to direct the flow of the mixture as they want it to maximise the efficiency of the engine. This does increase the performance of the engine but only if the straight is substantially long.