How To Trick Out Your Stock Cylinder Heads

Porting
It's true that a lot of extra airflow can be realized by porting the runners, but it's just as easy to ruin a good set of heads with a bad porting job. To port a cylinder head means changing the size, shape, and finish of the runners. It's a process done by hand or a CNC machine. Reshaping the runners' path, especially in the transition area where the runner necks down to the valve opening, increases the velocity of the air traveling into or out of the combustion chamber, making your cylinder heads breathe more efficiently.

Porting the runners is a job best left to your engine builder, but there are a few things a guy can do at home. An easy procedure is called gasket-matching. It involves grinding away extra material at the port opening so it matches the exact shape of its gasket.

If your budget permits it, you could have your heads fully ported. If not, look into what's referred to as pocket-porting to clean up the area in the bowls and the transition area between the runners and the valve seats. "It blends the valve job into the bowls and you can gain 20 to 30 hp if this is done properly on stock heads," Mamo tells us. It's more affordable, too. Pocket porting may run you about $300.00, compared with a $1,000.00 port job.

Ambitious sorts can take a stab at pocket-porting their heads in the interest of saving money. Massingill tells us he used to always pocket-port his own heads. But this brings us to the inevitable conclusion: Is all this work worth it? How much money will you have invested in hopping-up your stock castings and how does that figure compare with what it would cost to buy a set of aftermarket heads?

"The problem is that you're working with old technology with stock castings," Mamo says.

"That is the age-old question," Massingill quips. "The cost of new heads is so affordable and the technology is so good that it is almost a better investment to spend your money on aftermarket heads." He admits he often counsels his students at the School of Automotive Machinists to skimp on building the short-block if money is that tight and spend the extra money on cylinder heads as long as the reliability of the short-block is not compromised.

Our guys all agree that stock heads should at least get a good valve job, back-cut valves, and have the bowls pocket-ported. The bill for all that work can quickly run up more than $600.00, and that's not much of a screaming deal when you figure you can buy a new pair of aluminum Patriot cylinder heads for small-block Fords and Chevys for less than $1,000.00. Most new aftermarket cylinder heads are probably better out of the box than your stock heads, and many are better than OE heads could ever be, no matter how much money and work you throw at them. The Patriot Chevy heads offer similar performance to a factory Vortec head, one of the best production heads GM has made. And according to Mamo and Massingill, production Ford heads flow so badly, you're almost better off buying aftermarket heads from the start. Do your research when deciding where to spend your money.

By John McGann

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