View Single Post
ChrisBennet ChrisBennet is offline
Registered User
ChrisBennet's Avatar
Join Date: Aug 2001
Location: Nashua, NH USA
Posts: 8,089
Re: Help - 964 head gaskets again...

Originally posted by Sid
Chris (or any else who might be able to tell me..)

I note that you measured the groove on the barrell before you realised that there was still some of the original aluminium gasket left (and hence the heads did not sit very well). Did you measure the depth of the groove when it was fully cleaned?
I ask because I am considering modifying my barrells to accommodate the new gasket (my car is '90C4 with no gaskets and a combustion leak and a v.tight budget...)

I know that the 'proper' way is to replace all the pistons and barrells and then have the heads skimmed (as per Adrian Streathers book etc). I have also read that a 'fire-ring' can be used as an alternative to the latest steel gasket - but I cant find any details of this fire-ring anywhere or the groove that should be machined into the barrell to accept it.

Help/info/comments gratefully received.
Sorry Sid, I didn't measure the groove depth.

I've heard of people adding the groove to the earlier cylinders but they also added material on the sides of the cylinder. If you look at the picture of my cylinders you can see how close the groove comes to the edge. The early cylinder's mating surface isn't as wide so I think if you machined the late style groove it would either hang out the edge or come very close.

If you're on a budget, get some used late style cylinders and have the heads modified when you have the valves done. The 2 places I checked had them for $800 and $1000 a set. I realize none of this is cheap (wait till you see what 964 valves cost), only cheaper than brand new P&C's.

The late style heads do not have a groove in them, they just have a wider machined face to match the wider cylinder sealing surface.
'80 911 Nogaro blue Phoenix!
'07 BMW 328i Coupe
Old 11-01-2004, 04:41 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #15 (permalink)