Valve-Piston Clearance

With my adustible pushrods in place, I can now get an idea for how close the valves will get to the pistons when everything moves together.

With the head off and a piston installed, it was a perfect oportunity to check the deck height:

Measuring deck height on a Porsche 914 engine


It's measuring up at 0.022" which will give me a static compression ratio of about 9:1.

Now, I borrowed some of the boys' Playdough and put it on top of the piston. After putting the head and valve train back on, I turned the engine over a few times - relieve that I didn't feel any hard stops! Here's my Playdough after taking the head back off:

Measuring valve clearance on a Porsche 914 engine


I was thrilled to discover that I have plenty of valve clearance! The exhaust valve didn't even touch the Playdough, and the intake valve only made a small indentation. Here's a cross section to show how much clearance there is:

Putty showing the valve clearance on a Porsche 914 engine

Previous    Next

All pictures and text copyright 2008