PDA

View Full Version : What head will flow better


White325is
03-04-2007, 11:19 PM
ok i have a 325e and iam doing a E to I swap and i have the chance to just get a I cam and valve springs now i know the intake ports are bigger on the I head so would it just be better to go with the I head or keep the E head swap the cam and springs then spend the time opening up the intake ports and whats the difference in the intake and exhaust valves or are they the same size just the ports are different
if someone could help me out on this that would be great
thanks

e30_325es
03-04-2007, 11:33 PM
E valves are 2mm smaller than I valves, both intake and exhaust. It's really up to you if you want to port the hell out of an E head so that you can retain an E's CR, or if you want a better flowing head and a drop in CR. I think that a ported E head will allow you to keep most of the low end, while an I head will give you a slightly better top end.

bottlecape30
03-05-2007, 12:55 AM
If your going NA port the e head. If you are going to change your pistons go with the i head.
Althou the i head is much better design, it does not match up to the e piston design.