GASKET MATCHING VS PORT MATCHING

This is a commonly misunderstood subject. Many people think and believe the proper method of port work is to use whatever gasket comes in the box as a template to determine what size the ports or runners should be. It's not that easy or simple. I have seen many sets of heads destroyed by using this method. They look impressive to the untrained eye. You might even show some improved performance over stock, but overall you've created some airflow issues that can't be fixed. To assume that the gasket is an intelligent being would also be to assume that the gasket maker knows what size your ports should be. That is to assume also that the gasket maker knows your cubic inches, cam size, carb cfm., gear ratio, valve size, and RPM operating range, and more. Here's the story on gaskets. If gaskets protrude into the runner then shave or cut the excess off so that it doesn't obstruct air flow. That's it! Don't use gaskets as templates. My next post will be discussing the rest of port matching that wasn't handled here. - The Head Doctor

Dr. Denny does custom head porting & polishing. For more information go to DR.DENNY.COM