elanman

Putting the head back together after cleaning and new stem seals
Little unclear what the length should be for the measurement between the spring cup in the head and the retainer. Should it be set to 41.0mm on both inlet and exhaust with the shims? This is a 87 turbo cylinder head, I cant access a turbo manual. Early NA heads have different lengths for exhaust and inlet. What does the Porsche manual mean 41+0.5? Is that between41.0 to 41.5mm but should not be less than 41.0

(An update on cleaning- Never found anything to clean off baked on carbon in exhaust ports. I had to carefully remove it by manually chipping it away carefully and then with rotary wheel brush.All ceramic on exhaust ports appears intact

gruhsy

I keep posting about cleaning anything on our cars with Naptha

Nothing works better. I used it on the ports on my cylinder heads I have.

It's used as a final cleaning product prior to painting. You can buy it at an auto body supply place for sure. I purchased mine through a vendor that sell to my work however.

Take a look at the latest photos on my thread.

I will try to remember to add some photos of cylinder head cleaning today.

Naptha cleaned off the carbon deposits in the ports on my heads.

https://rennlist.com/forums/944-turb...old-car-4.html

https://rennlist.com/forums/944-turb...fuel-rail.html

931guru

Yes, 41+0.5 means exactly that. 41.0 - 41. 5

I have attached a pdf from the 944 turbo tech specs book. It seems that the turbo and the 8v na heads have the same installed valve spring length.

elanman

So the lengths are different for exhaust and intake for a turbo M44/51 which I believe my 87 turbo is

41.0 for intake and 40.0 for exhaust

Good to see it from the Porsche manual