Originally Posted by foxmustang
Hopefully I attached these right, here is some of the portwork that I have been doing on a set of d0ve C heads. Please let me know what is though of it and what should be improved. I have not done any gasket matching yet. All of the work has been done to the bowl and runner. This is all on the exhaust side, I have only smoothed the castings on the intake side. I have to buy longer burs before I really start on the intake.
I dont know if you can really tell or not, I have taken the buldge out of runner where header bolt is by atleast 70%.
Also there is surface rust in these photos (I forgot to put oil on them so they wouldnt rust).
I would estimate from the port
work (your bowl
work is not shown) that you have increased max flow capabilities by about 18-20%. Good bowl work and especially good combustion chamber-to-seat-to bowl work is critical as well.
That exhaust port, as you have shaped it, will allow for notable power gains, perhaps 25HP on a stock engine and much more with a cam that would open the exhaust valve more and take advantage of the freer flowing port. Careful that you do not grind the smog bump down (that was on the right side of the port roof) any lower than the actual roof of the port...or you risk hitting water.
Bigger is not always better and depending on what you are building for an engine, you likely don't want to gasket match the exhaust side. Also, believe it or not the exhaust manifold bolt boss (on the LH side of the port wall as you look into the port from the exhaust manifold side of the head) is better left untouched.
I suggest you stop from any futher "hog & hope" porting as some of what you have already done actually restricts the possiblity of your heads ever being a "champion" set of ported iron heads. But rest assured that you have indeed increased the hp potential of your engine build.