Austin09

Hi all,

Hoping someone will know the answer to this. I have a crack in my cylinder head and it will need replacing.
I've been looking and some reconditioned used heads, does anyone know if I can use the 250bhp head on my 220bhp car. Mine is a 1987.

Aside from Porsche main dealers, is there any where else to got to get a new one if I wanted to go down that route?

Thanks!

carlege

There isnt any difference between the turbo s head and turbo head.

Paulyy

All the same. only difference is the 2.7 8v head.

Austin09

Is it the same part number? When I called porsche they said the 220bhp part number for my m44/51 car has been superceeded but wasn't sure if it worked on 250bhp cars.

Is the turbo s a surperior head but directly compatible?

carlege

its the SAME

Thom

It's nice to upgrade to the later style oprv if your old head has the ball type oprv.

Voith

You can even use na head with valves and springs from yours. Can you post the picture of crack?

Tom M'Guinn

The extra horsepower in the Turbo S came from the turbocharger itself and extra boost pressure, not the head. So there is no such thing as a 250hp head, per se. When fully assembled from the factory, the Turbo S exhaust valves were 1/100 mm thicker than the non-turbo exhaust valves, so that may explain in part the updated part number. For your purposes, any turbo head from an '86 to '89 944 Turbo fit and work exactly the same as any other. Brand new heads are very expensive, but used heads are very cheap (go figure), so most folks just find a good used head and give it a valve job and resurfacing. If you go that route, look for a head that has not been surfaced already, and check that the deck and cam tower surfaces are flat (using a precision straight edge), and inspect the ceramic liners in the exhaust ports for signs of cracking or chipping.

p.s., are you confident your head is cracked? That's sometimes a hasty but incorrect conclusion by mechanics who are not familiar with the 951's proclivity for head gasket failures...

rlm328

If you don't want it send it to me.

blade7

If the rest of the head is good I'd have a proper prep and weld done on the crack. then a skim.

V2Rocket

ive got a 1986 951 head with some missing ceramic in the #1 exhaust port, complete and in good shape, needs rebuild...$100+shipping...

Austin09

I'll let everyone know what the machine shop says.

While the head is off, whats the best way to check for the health of the block? I did a compression test a few miles before the strip down and it was all great, but i don't know if the bores for cycling 1 or 4 are scored given its in TDC. I don't want to spend a fortune on a new head if the block is trash.

Also, when reinstalling, can I get away with reusing the head bolts?

blade7

I'd put the head back on that block if all the compressions are good and equal. If you mean can you reuse the studs and nuts the answer is yes if the threads are in good condition.

carlege

While its off i would get it reconditioned. Effort and time to do it again would out weight my willingness to spend 500 getting new valve guides and everything done.

What were your symptoms to make you think your Head was bad?

Austin09

While it is exposed.... how can i test the condition of the pistons / rings and bores. I did a compression test before, but now its off can I check the block?

As for my head, its with the machine shop now and I'll feedback anything with pics in case its helpful to anyone. Water must be getting into the exhaust port somewhere but I can't see where.
I may recondition mine but only if the block is decent.