Porting cylinder heads has long been a right of passage for serious hot rodders looking to add power on a modest budget. Armed with the right knowledge, the correct tools, and a couple of nights in the garage, it’s an easy and almost free way to pick up airflow, which results in increased power and decreased e.t.’s at the track. However, with the wrong knowledge, or an overzealous hand, home porting of cylinder heads can literally ruin a set of castings, taking them from a quality off the shelf piece to a set of paperweights in less than a minute. And because of this, it’s pretty difficult to find anyone out there willing to show the ins and outs of a hand-porting job, since it’s easy to put the wrong info into the wrong hands. Well, that, and the fact that cylinder head porting is more akin to a witches’ brew of knowledge and experience than a straightforward bolt-on modification. But that doesn’t mean there isn’t hope for the budding enthusiast looking to modify a pair of heads in their free time and try them out on the engine of their choice.
This month, we’ve teamed up with Gabe Darveau, of Vengeance Racing, to go behind the scenes of a cylinder head porting job. Gabe’s been doing this type of work on LS cylinder heads for years and has been taught by some of the very best at the School of Automotive Machinists, where he honed his skills before heading out into the performance aftermarket. What Gabe shared with us was a meticulous approach to cylinder head porting backed by science and experience, both of which we can learn from and apply to our at-home projects. If this is going to be your first time jumping into a set of ports, we recommend you get a spare set of cheap castings and think of them as an experiment; cylinder head porting is tricky and you can “find air” on a set if you go too far…so take your time, do your research, and think before you grind. If you’ve been around the game for a long time, feel free to combine these tricks with your existing knowledge to tweak just a little more out of your hand ports, as there is practically never enough to learn about the world of airflow as it pertains to an engine combination.