ok what I'm wondering here is where are the weak spots on head flow?

I know a lot of ppl shave the area near the valve guide to help out with flow and a few other things that I don't remember right now and wondering how just doing a few minor things like this to the head would help out with power?


I'm not interested in making the ports much bigger if anything would like to do it removing the least amount of material possible and instead just remove restrictions or reshape a little. this way I can still keep the low end power.


also on top of just how much of an ipmrovement can be made by reletivly minor head work what impact would just a basic head job do for gas mileage?

 

Have you checked out the Standard Abrasives Do-it-yourself Porting Guidelines?

Most of the gains appear to come from cleaning out the bowl under the valves, where the factory machining operation stops and leaves a ridge in the casting; and the "short side radius", the transition from the port to the valve on the "inside" of the turn.

Next is valve shrouding - depending upon the size of valves & chamber you have, may or may not be an issue.

Smoothing out/reducing the guide seems to be of benefit as well.

 

how would this minor reshaping affect gas mileage?

I'm interested in getting a little more pep without losing gas mileage and if anything would like to improve it

 

With which head castings will you be working?

 

first car kinda depends
a friend and I are going junkyard shopping tomorrow to see if we might be able to pick up a decent set of heads for a fairly mild carbed 350. mostly stock other then what we think is upgraded cam and edlebrock carb


the other car that we might try this on is the ol' cvcc honda head

and if all works out might have another car to try it on as well while doing a mild buildup of a poncho 428


the 428 is on hold for the time being though the main motors are the 350 which the heads I can get the casting number tomorrow if you want but that can change when we go junkyard shopping if we can find another good set of heads. any recomendations? and the cvcc honda head