Cylinder Head Theory

You can also pour the intake and exhaust runners the same way. For the intake runners, lay the head on its side with the intake ports facing up. Put a little Vaseline on an intake valve stem and valve face where it seats in the head to prevent leaks, grease the intake port and place the plexiglas over the intake port the same way you did for measuring the combustion chambers. When you've done the intakes, turn the head over so that the exhaust ports face up and repeat the process with Vaseline on the exhaust valve face and stem. It won't take a whole lot of Vaseline on the valve stems, just a light coat. You just want to prevent the alcohol from leaking between the valve stem and the valve guide. If you put too much on, the glob that results will skew your results and make the runners smaller by the volume of the glob. If you pour the chambers, intake runners and exhaust runners and record the results, you will be armed with information that will help you to know what to do next. Choosing the proper cam for a street motor requires that you know the actual static compression ratio of the motor and to do that, you need to know the exact volume of the chambers.

You can also pour the intake and exhaust runners the same way. For the intake runners, lay the head on its side with the intake ports facing up. Put a little Vaseline on an intake valve stem and valve face where it seats in the head to prevent leaks, grease the intake port and place the plexiglas over the intake port the same way you did for measuring the combustion chambers. When you've done the intakes, turn the head over so that the exhaust ports face up and repeat the process with Vaseline on the exhaust valve face and stem. It won't take a whole lot of Vaseline on the valve stems, just a light coat. You just want to prevent the alcohol from leaking between the valve stem and the valve guide. If you put too much on, the glob that results will skew your results and make the runners smaller by the volume of the glob. If you pour the chambers, intake runners and exhaust runners and record the results, you will be armed with information that will help you to know what to do next. Choosing the proper cam for a street motor requires that you know the actual static compression ratio of the motor and to do that, you need to know the exact volume of the chambers.