944 S2 w/968 head?

[Mike the mechanic]

Hi guys, don't know much about the 944 and 968, so a little advice is needed!

What would it take to bolt on a 968 variocam head to an 89 S2? I know they are both 3litres, I know the head must bolt up to the S2 block, but what else will be needed for the swap? Also, will there be a power increase?

Just need to know what parts are needed, like timing belt, etc..

Thanks!

[SlowToady]

Um..I think the water passages are different, and I think the 968 block might actually have some cylinder placement differences, so I'm not sure if the ports of the head and the cylinders would line up.

I might be wrong though.

[mike944]

The bare head for the S2 and the 968 head are almost identical. The differences are in the cams, the chain between the cams, and the variocam actuator, the mounting pads for the actuator, and the valve cover. It should bolt right onto an S2.

Here's where the trouble would lie: You would need a way to actuate the variocam mechanism, since it's electrically driven. Search 968.net for the RPM ranges that it's active in. I believe it's "on" below 1500-2500 RPM (load dependent) it's "off" above that, and switches back "on" above 5500 RPM. It's matched to the dual-tuned 968 intake though, so you would probably need that intake as well to realize any power gains. I don't know if the pistons are the same, so there could be valve clearance issues as well.

[Mike the mechanic]

Thanks for the info, guys. Is the variocam electrically activated by the ecu like Honda's Vtec? If yes, they sell rpm switches that can control that.
The reason for this swap is due to a cracked head on an S2, and we are having trouble locating a good S2 head. We came across a good used 968 head, and thought it would be a good thing, since power can be gained also.
But, upping the power is only secondary to getting the car back on the road.

So is this something you guys would do? Or just wait until a good S2 head turns up?

Thanks!

[fast924S]

Well If its a project car and you had some time to play with it, I would do it. But if its a daily then no way

[mike944]

How much are they asking for the head? does it come with cams & variocam mechanism? 968 heads with all of the above routinely go for $1500-$1800 USD. You need to inspect the cam gear teeth carefully for undercutting. This can happen when the chain stretches, and if it's severe, then the cams are not usable anymore. At the very least, you'll need to replace the chain ($30) and variocam tensioner pads ($60) as these are problem parts on the 968 head.

Yes, it's activated by the ECU, and there's no reason why you couldn't actuate it with an RPM switch. You could experiment with RPM settings looking for more power. I believe the low-RPM "off" position is only to improve emissions, and may not be needed. Beyond that, you'd only need the RPM switch to turn the variocam off at your desired RPM. This could be your only issue, since RPM switches usually turn things on at high RPM

Read the article below for variocam information.

As far as whether to try it or not? Personally i'd reccomend sticking with the S2 head, since by the time you figure out the tuning and any problems that may crop up, it may have been quicker to wait for an S2 head. But.....If you're like me, and would want to undertake a potentially challenging project, Go for it!

Link for variocam information: http://www.968s.com/DIYPDF/
Click on the one that says "procedure for inspec..>" I can't give you a direct link, because it doesn't work correctly that way

[operationcougar]

i like the idea, i dont know much about the 944 yet (still learning with the first) but the idea of frankenstiening a better head seems like a great idea, ive done it with hondas in the past many times and always worked out for the better-and when installing a turbo/supercharger it takes 50% of the headache out of the whole situation

[944 Ecology]

We have a couple of good S2 heads in stock at the moment.

gb

[operationcougar]

but if it works, just please -- LET ME KNOW --

[will944]

Yes....please update us on what you decide....I am very interested in this idea.

[Z-man]

A 968 head won't fit on a 944 S2 block. When my 944S2 head went this summer, my mechanics looked at this solution and determined that the 968 head would not match up with the 944S2 block.

I wound up getting a refurbished head from Porsche AG for about $2100.00. Yes, this is more than going to the private market, but when the head arrived, to my surprise, it was not a stripped head, but it had the valve guides, valve springs, EVEN all 16 valves! (remember, our valves cost about $93.00 PER valve). Plus since it was bought from Porsche directly, the head has a 3 year warranty.

Good luck!
-Z-man.

[SlowToady]

A 968 head won't fit on a 944 S2 block. When my 944S2 head went this summer, my mechanics looked at this solution and determined that the 968 head would not match up with the 944S2 block

That's what I thought..and was trying to get at. I read somewhere that the the two blocks have their cylinders in different locations.

Holy cow, just the valves for that head are just under $1500; that's a pretty good price, IMO, for that head Z got.

IMO, I'd just do like Z and get a head from Porsche.

[operationcougar]

is there anything out there as far as frankenstein heads? anything high perfromance around those lines would be great

[carsontc]

Originally posted by Z-man
A 968 head won't fit on a 944 S2 block. When my 944S2 head went this summer, my mechanics looked at this solution and determined that the 968 head would not match up with the 944S2 block.

what am I missing here?

[SlowToady]

Originally posted by carsontc
what am I missing here?

Cylinder placement. The blocks are different.

[Z-man]

Originally posted by SlowToady
That's what I thought..and was trying to get at. I read somewhere that the the two blocks have their cylinders in different locations.

Holy cow, just the valves for that head are just under $1500; that's a pretty good price, IMO, for that head Z got.

IMO, I'd just do like Z and get a head from Porsche.

Sometimes, when you pay a little more, you GET a little more!
-Z.

[Panzer909]

Originally posted by Z-man
..................I wound up getting a refurbished head from Porsche AG for about $2100.00. Yes, this is more than going to the private market, but when the head arrived, to my surprise, it was not a stripped head, but it had the valve guides, valve springs, EVEN all 16 valves! (remember, our valves cost about $93.00 PER valve). Plus since it was bought from Porsche directly, the head has a 3 year warranty.

Good luck!
-Z-man.

That's a darn good price for what you got - especially if it came directly from Porsche. Was there a core charge at all?

[Z-man]

Originally posted by Panzer909
That's a darn good price for what you got - especially if it came directly from Porsche. Was there a core charge at all?

IIRC, there was, and unfortunately, where my head cracked up top, and they didn't want it! The charge wasn't that high though - a couple hundred dollars. Still a good deal.

-Z.

[carsontc]

Originally posted by SlowToady
Cylinder placement. The blocks are different.

how are the S2 block and 968 different? ok the 968 has additional cooling via piston squirters...but what else?

[AznDrgn]

That is very interesting since I've heard of S2 and 968 racers swap blocks back and forth using either head. As far as I've seen there are some small differences but they are interchangable. Also the idea that the cylinders are in different places is odd since they use the same head gaskets .