This is a ported '70 351w head (DOOE). 160cc intake volume. I ported these heads in 2002 and they are on a 331 Ford. I never had them flowed, but with nothing radical, the engine is making peak power of 420 HP @ 6500. Power drops off about 30 HP @ 7000. It runs very well and it really loves to rev. This mold was made from a spare DOOE head that I experiment with. If I ever take my heads off, I would not mind spending a few more hours making some port improvements while i'm at it.
Cam is a Comp 282S with 236@.050 and .528 lift. I have Probe 1.7 shaft rockers so the lift is .560 minus lash. I also have a ported and port matched Victor Jr intake, 750 HP carb, 9.7:1 compression and Dougs tri-y headers.
The min CSA in this port was a few inches into the port. It was about 1.72 sq. in. and is it now 1.92 sq. in.
What I did to the port:
- raise the roof of the intake port about 1/8"
- cleanup the pinch area which opened it up to 2.02 sq. in.
- opened up the bowl to 90% of the intake valve diameter
- widened the runner after the pinch and before the turn about 1/16" per side to 1.92 sq. in.
- layed back the short side radius.
What I noticed from the mold:
- The valve pocket around the guide is deeper on one side than the other. Should I deepen the other side?
- The roof of the runner inlet where I raised it has a bit of a curve to the roof and it could be straightened out. Leave it as is?
- The short side radius looks good. Leave it as is?
- Except for the inlet, the CSA through the port is fairly consistent. It varies from 1.92 to 2.16 sq. in.
- The diameter of the bowl is about 90% of the intake valve. Should I try for 91% or 92%? Its only .015 to .030 more