Intake/head port mismatch
08-08-2011, 09:31 AM
#1
Intake/head port mismatch
This past spring I upgraded blowers, from a 177 to a 250. Turning the blower slower now. Was running 5psi on the 177 at a 2.15 ratio, and 5psi on the 250 at a 1.6 ratio. Even tried 7psi at 1.8 ratio this weekend. Problem is, I havent really gained anything power wise, maybe even lost a little. The 250 blowers have good teflon and low hours.
One thing that I noticed, when installing the new intakes, is that the intake ports are larger than my head ports. They are older Dart aluminum heads, rect port. There is a wall, lip, or whatever you want to call it, when looking down the plenum into the runners, on the bottom/floor where it meets the head port. Rough guess is maybe 1/8", maybe even 3/16.
Some people say this should'nt be a big issue being that its a blower combo, some say it can rob lots of power. I wasn't expecting a big power increase, but was hoping for a tad more, and definitly not a tad less.
Either way, i plan to port match the stuff over the winter, but still would like to hear some thoughts on this.
One thing that I noticed, when installing the new intakes, is that the intake ports are larger than my head ports. They are older Dart aluminum heads, rect port. There is a wall, lip, or whatever you want to call it, when looking down the plenum into the runners, on the bottom/floor where it meets the head port. Rough guess is maybe 1/8", maybe even 3/16.
Some people say this should'nt be a big issue being that its a blower combo, some say it can rob lots of power. I wasn't expecting a big power increase, but was hoping for a tad more, and definitly not a tad less.
Either way, i plan to port match the stuff over the winter, but still would like to hear some thoughts on this.
