What Specs to resurface head???
 

2.5L 85 -66K restore: head off and cleaned, the usual corrosion in the water jacket areas of the head. Can anyone provide information on the amount to
cut and then which thickness of head gasket to use? My machine shop had something in PROISIS for a measurement "from the valve......" but the entry was incomplete. This appears to be the first time the head has been off. I'm hoping for a cut, say .5mil that lets me use the regular gasket, and retain the compression ratio +/- , or at the other extreme, not use too thick a gasket, increasing the quench area volume too much.. Please help with the right info.

thx very much

The "recommeded" specs. are in the FSM, and how to measure the head. They so say to only shave the most minimum amount to get "flat". You must not have that info? If not, you NEED to acquire it. A Porsche familiar machine shop, WOULD have that info, and should be able to make a decent suggestion to you. I'm running an '83 with a head shaved approx. .018", and using the stock sized gasket. It does boost the compression ratio, but you must understand this, and consider other things.........sometimes. FSM, says to go to the oversized gasket, with this much shaved. You do, need more info. Wished I could help more here, right now. Good luck!

Right, so if I had the FSM, and found a Porsche source
that would readily provide this info without obligation for service, I wouln't need the help of the fine folks on this board?

Thanks for the anecdotal info, I'll keep looking.

That makes me curious. The head i just took off an 85 if i remember correctly had rienz turbo headgasket. I'm asuming this is the oversized one or the turbo Gasket is the same as an NA for an 85.5 model?

I'll get the new gasket set tomorrow- I'm told and read elsewhere that the turbo gasket is what is in all the sets
for the last few years of suppy. I'll measure it and the old gasket, compare and post the info.

If any one else can nail the data on cut versus which of three
thicknesses, it would be greatly welcomed
:rolleyes:

Ok, I think this is what you wanted to see?


http://forums.pelicanparts.com/uploa...1138153495.jpg

sorry, I've got a new computer, new software, and I'm an IDIOT with it! I'll keep trying!

Ok, we will try from the old computer. GOD this thing IS slow!

http://forums.pelicanparts.com/uploa...1138155691.jpg

I'll be! It worked! Just for GP, this is what FSM says. You can exceed the limit (slightly) and still use the stock gasket. I am currently doing so, and I know many others are also. Just know what the "book" says. :)

Don't worry that is says "turbo" on it. They ALL do now. It will work just fine.

Yeeaaaaaahhhhhh baby, !!! Thanks a lot Granite!

I was also able to get the FSM info!!!

Off to the machine shop!!!

best

Here's the result! Resurfaced .012 to clean up the fire
ring and ports. Also the original gasket pics holes
and all the mess. The cut more than doubled the area
behind the fire ring for a clean seal.....http://forums.pelicanparts.com/uploa...1138334121.jpg http://forums.pelicanparts.com/uploa...1138334221.jpg