Stupid Question Re 968 head
- Thread starter colin944
- Start date
JamesO
New member
I ran an S2 head on a 968 block for a while so I see no reason it wont work the other way round. The 968 head has bigger valves and ports plus the different cam set up, so you would need the 968 cams and tensioner too.
The valve cover is even swappable (except the hole for the variocam solenoid)
ETA
The inlet manifold also fits both heads.
The valve cover is even swappable (except the hole for the variocam solenoid)
ETA
The inlet manifold also fits both heads.
924nutter
PCGB Member
Succinctly put. Best contemporary road test on a new 968 was 232 bhp wasn't it, and most of that due to the bigger valves I shouldn't wonder. Would S2 cams in the 968 head work well? This assumes that the slipper can be locked in the correct postition to emulate the 944 set up. I suspect that it would make the S2 more top endy, due to the reduction in gas velocity brought about by the larger valves. ( to sweep a given volume of gas through a larger orifice would reduce its velocity)
JamesO
New member
Unfortunately the s2 cams won't fit iirc the sprockets aren't in the same place. I have seen 968 engines on the web using fixed cam timing somewhere I'm sure. One had two cam pulleys to eliminate the tensioner and chain iirc. I was trying to find a way round broken cam sprockets on my engine and went for the s2 head for a while.
Neil Haughey
New member
Ask EMC, Alex Eacock built an S2 endurance race engine several years ago that used the 968 top end with S2 manifolds etc.
The inlet valves are loads bigger but the question is does one really want to rev the nuts of the S2 bottom end? I have been advised by them many times for example to be careful about revving the engine round past 6500 rpm as a lot of failures under racing conditions seem to involve lots of revs. On that special engine they would have used their custom all steel bottom end as seen on the website.
The inlet valves are loads bigger but the question is does one really want to rev the nuts of the S2 bottom end? I have been advised by them many times for example to be careful about revving the engine round past 6500 rpm as a lot of failures under racing conditions seem to involve lots of revs. On that special engine they would have used their custom all steel bottom end as seen on the website.
Neil Haughey
New member
Yeah I am fairly sure I read either on here or on 968uk that someone tested it and without the variocam the engine would either make 7 hp more or 7 lb/ft less depending on how it is set. ISTR it was Barry Hart who did the testing as I believe he had some system for controlling the variocam solenoid.
Ex Skyline
New member
Give Jon' Mitchell a bell [
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Indi9xx
New member
Electrically.. For the variocam to work on a 944 S2 ecu and loom, just add a £50 off the peg rev limiter and a relay to switch it at a what ever point you choose.. Then a custom remap just to get fuel and spark to match the new cylinder filling. I would probably recommend using a bit of logic to make sure it only switches at full throttle and remap the full throttle map for it in one variocam mode and the part throttle maps for the other variocam mode.
Mechanically, using the 968 head, you could just bolt it on and suck it and see, but that could wind up with the chance of valve to piston collisions at high rpm.. in some cases it should all clear, but sods law will say a set of used springs, a slightly worn cam, s2 pistons and 968 valves may hit a anti-sweet-spot and result is a nasty mess...
968 and S2 cams do indeed have different sprockets
Mechanically, using the 968 head, you could just bolt it on and suck it and see, but that could wind up with the chance of valve to piston collisions at high rpm.. in some cases it should all clear, but sods law will say a set of used springs, a slightly worn cam, s2 pistons and 968 valves may hit a anti-sweet-spot and result is a nasty mess...
968 and S2 cams do indeed have different sprockets
Indi9xx
New member
Experimentation is cool.. Go for it!
I have always wanted to build an experimental 944 engine, not to be the biggest, or the baddest, but to build one to destructively test just how far the engine could be put on a diet and remain reliable, I am pretty sure the internals could be put on a diet and loose 30% of their considerable internal mass, as well as loosing about 40% from the clutch and flywheel weight, and still remain reliable... It might idle like a muscle car.. but it would pick up like a motorcycle engine and loose a massive amount of parasitic losses, add to that a dry sump, make it breathe and raise the rev limit and I think it would be an awesome engine.
But, I never get round to it.. I should.. Build that 968/S2 hybrid!
I have always wanted to build an experimental 944 engine, not to be the biggest, or the baddest, but to build one to destructively test just how far the engine could be put on a diet and remain reliable, I am pretty sure the internals could be put on a diet and loose 30% of their considerable internal mass, as well as loosing about 40% from the clutch and flywheel weight, and still remain reliable... It might idle like a muscle car.. but it would pick up like a motorcycle engine and loose a massive amount of parasitic losses, add to that a dry sump, make it breathe and raise the rev limit and I think it would be an awesome engine.
But, I never get round to it.. I should.. Build that 968/S2 hybrid!
edh
New member
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