S'up guys... just gopt my '83 944 a month or so ago. Question is, i have a 2.5 block, bored to 2.7. I have a chance to get a S head with cams, turbo valves, port/polished, 5 angle valve job, and shaved a couple hundredths. All this for 1100. Should i get the head? Worth it? And the moain question, will the water/oil passages line up? also, my balance shafts were eliminated so what about my timing belts, and the sprockets? Thx in advance

 

Ummm, NO! however for $900.00 you can have your own head Ported, Polished, rebuilt, and computer flowed and you will be in business my friend. Lindsey racing or Powerhaus can do it for you.

 

He also wants the benefits of the 16 valve "S" head as opposed to the 8 valve head that comes with the stock 944. It is a rather expensive swap but can work. I think it will bolt on -- *BUT* you have to replace the ignition system, cam timing and the balance shaft belts & Pulleys, balance shaft, the DME and the intake system. I think the S has better heat exchangers too. I'm not sure if having an early 944 will cause any additional problems. The real S had lots Turbo parts throughout.

For all of this you only get 20 - 30 HP. Buy a good exhaust and "chip" the car and you'll get around as much HP for a fraction of the cost. Personally I'd stop there (with maybe a new Suspension). If you are into major MODs that might blow your engine buy a supercharger kit. You'll produce loads of extra HP. You'll need to rebuild the engine and upgrade just about everything else first. But the power ...

 

So ah... which Turbo parts are on the S that's not on the normal 944???

 

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Let me enlighten you a little bit..

The s head will fit WITHOUT modification on ANY 2.5 block - no water problem.
You will have some machining of the 100mm head to match a 2.7

The above DOES NOT MATTER because you are not going to buy an S head that someone has told you has TURBO valves - IMPOSSIBLE - way too big, heads and stems. RUN away from anyone who told you it has turbo valves.

Also - I am sure you are aware that the s head has oval ports, and a different rail.

If you need any further info, e-mail me and I will give you real, non-speculation info on these heads.

 

Special Tool: From what i understand is that the the intake valves are larger and oval on the S head compared to the 951 head. However, the exhaust valves are fine but isn't really required because no turbo is being used, if he is planning on turbocharging it ($$$$) then he should adress the springs as well (from the 951 also). But the 951 valves are also ~0.5mm shorter than the stock S valves, no problem since shims could be used to compensate that.


You comment on 951 valves NOT fitting a S head was slightly off, but i agree with the intake valves (size and shap are different). So i do not see a problem with a S head fitted with 951 valves (again it isnt needed unless you need some serious HP/TQ numbers which is where a turbocharger is required).

 

I think you guys are getting the '88 4-valve 2.5L 944S head mixed up with the '89 2-valve 2.7L 944. The 2.5L 4-valve S head will bolt right onto a 2.5L 951 100mm-bore block without any problems. The 4 valves in fact are all smaller than either of the 2 valves in the 951 head. The '89 2-valve 2.7L 944NA head is another unicorn. This head bolts onto a 104mm-bore engine and has intake-valves that are 3mm larger than the 951. However this head WILL NOT bolt onto the 2.5L 944/951 block, even one bored to 2.7L because the water-passage in the front corner is configured for the 3.0L 104mm engine. This head is usually prized by those seeking to turbo 3.0L engines because the head can use 951 intake-manifolds and headers without any mods needed, AND it will fit onto a 104mm block.

 

I was just relating the steps a friend of mine took to make the swap. Some (not much as I recall) machining was also required. In the end the HP gain was never really worth the effort. The car did run well though – even passed a smog test before he sold it. This all happened about 5 years ago but I do remember it pretty well.

The parts I listed are pretty extensive. I think the clutch and breaks are different on the S too. Wasn’t the suspension also tighter? I could be wrong I never owned an S model.

The bigger belts and pulleys were an important upgrade as adding the S head is more that just a little modification to the standard engine. With the S head a broken belt can end up eating up the cam sprockets – the head itself can also be damaged beyond repair. Treating this like a quick bolt on type project will get you into trouble.

 

Well, considering the original poster has had his '83 944 for one month, and he's already got an engine thats bored to 2.7 ltrs... I am wondering who did the boring work, what pistons, etc?

Just one more example of someone who is going to create another firebreathing 944NA, eh? lol Best of luck, you'll need it.

Regards,