HughA44s

Is there any performance to be gained in putting 944 T valves and springs in a N/A head? I realize other areas need to be addressed but in general is this possible and does it make the head flow better? This would remain a N/A motor and cost is not to big of a concern as I will need to rebuild the head anyway. (stripped timing belt) Would I need to be replace the valve seats, or just regrind them? Any help appreciated. Yes I already used search and didn't come up with much info.

Zero10

Might as well have a turbo head put on if you want it, and it will give small if any gains.
You would need to grind the valve seats out quite a bit, as the turbo valves are bigger (I'm sure you know that part).

Skunk Workz

Hardly. Valves are same size,flow are just a couple CFM's different. The turbo has a better exhaust port,might help a bit...but not on stock cams.

Predator

I thought that the 944 8v head was exactly the same as the 951, except for sodium filled exhaust valves and ceramic exhaust ports? Worth about .oo1 hp.

special tool

Yes - the 951 flows about the same.
The sodium and ceramic allow you more boost/EGT margins, so that you can, for example, kick the **** out of any NA small block.

Skunk Workz

Nope,the intake side is virtually identical (valves are not the same,but same size) ,but the 951 exhaust has a tighter section right after the valve than the 944,slightly limiting reversion and making the overall (average) port diameter about 4mm smaller...improving port velocity.

tod84944

I have some experience with this. On the advice of Jim Pasha, I put a 951 head on a 88 block. Used the tube factory headers. I have only one thing to say about the difference.
......WOW.....
Of all the 944's that I have had, and still own, this is the fastest 8V car I have ever had. It is simply leaps and bounds faster than the other cars.
According to Pasha, putting a 951 head on a 88 block only (higher compression), would make a big difference. I was somewhat unsure if I could notice much difference, but after getting the car together, It was a ton of difference. I later added a K/N airfilter, and a Flow Master muffler. Even better. I then added a MSD coil and Jacobs plug wires, could not really tell much difference. Then added a PowerChips chip, big difference above 3K rpm.
So to answer the question, in my experiecne, putting a 951 head on a 88 block, yes it makes a difference. Not sure if it would make a difference on the 87 and earlier blocks, but it does on the 88

porschefig

cool, figured as much

Fishey

Does Turbo/NA use the same Cam?

MM951

Early N/A cam is same as Turbo cam irrc

Fishey

What about late Cams? Seeing as if one cam has more lift/duration I think it would help performance in a Turbo.

MM951

I think the late cams are different. How? I'm not positive..I'll search it

EDIT: https://rennlist.com/forums/showthre...early+late+cam

Zero10

Late N/A cam has 1* more exhaust lift, and 7* more exhaust duration (or was it 6*?...)
I am running one in my 951. I was told it helps cut turbo lag. Honestly I believe it does, but I made a few changes at once, and am unable to verifiably attribute it to the change in cams.

Skunk Workz

Hugh - If anything gave Todd an improvement,it was the turbo head. Not the valves alone. Said earlier,valves are same size,turbo head has a better shaped exhaust port. My guess is that the turbo exhaust port helps with scavenging,thus giving Todd his increase...

HughA44s

Thanks Skunk - Thats what I was trying to sort out.