Today I measured the Cylinder Head Combustion Chamber Volume. Also known as cc’ing the heads (cc = cubic centimeters). This is a process whereby we physically measure the volume of the combustion chamber.
You have to use this science lab setup looking setup with a buret. Nice intro video on YouTube. You also need a plate to cover the head and act as your fill limit. On some cars it would set on top of the head. On 356 / 912 it needs to go down inside where the cylinder sits, but remain on top of where the heads starts to angle. I made my own plate from a piece of 1/4 inch plex. I got the following measures for each part of the head in mL.
- 59.2
- 59.4
- 59.0
- 58.2
I’m not sure if this is a good spread or not. More research to do. I do know that these measurements are critical to determining the compression ratio of the engine. Ron LaDow has a great article on Why Should I Care About Compression Ratio?.
