azmi951

Anyone have pictures of the pads that you measure to determine how much your head has been shaved? Jon at JME said there are three pads and the stock thickness is .944 inches.

Thanks.

azmi951

no one has a spare head laying around they can take some pictures of???????

hosrom_951

Yes, there are three 'pads', and i measured them to be 0.5mm deep

Sorry, no pics

Pauerman

There's a witness mark on the deck's face. This mark tells you how much deck material you have left before reaching the minimum deck height. It's located just under the #2 intake valve. I'm working on an untouched stock head right now and the witness mark is ".022 deep.

azmi951

I was told that there are other ones not on the deck surface that can be measured without the removal of the head. JME said there are three of them and that they measure .944 and that the SCCA allow them the measure .913 and .929 for PCA.

Thanks for the input guys but I can not really measure the depth of the witness mark in the deck surface since it is on the head.

M758

There is a spec in the factory manual that mesures the head to block dimension. Not sure what it is, but you can measure it with everthing still in the car.

azmi951

Joe, where is that measurement taken at?
Thank you.

hosrom_951

Joe is right, technically the manual describes where you should measure, but because there is a lot of stuff in the way.........

Worth a try (look at distance A)

M758

That is the exact page I was talking about.

The measurement is not that hard to get to on an NA. I checked this out as a potential method to check compression on 944 spec car.

Does anyone know how much shave would get you to 10.5:1 CR starting the 9.7:1 pistons?

azmi951

That is it. Thank you.

Waterguy

0.76 mm (0.030")

There have been threads on this subject before, which included consideration of valve clearances.

M758

Thanks!