s2 or 968 head on 2.7 NA
06-01-2011, 06:01 AM
#1
Racer
Thread Starter
s2 or 968 head on 2.7 NA
Would this work without changing pistons? i.e. would there be the correct valve clearance? If not, would it be as simple as adding 968 or S2 pistons retaining the rest? I don't feel like shelling out for a 3.0 crank or new rods just yet...
The reason I ask is that I've been working on an ITB setup for a while now, and the s2 head would seem to be better suited as the spark plug is located on top of the head, not under the manifold as in the 8v.
My aim is not power so much as a free-revving, responsive 944. Think hachiroku
http://www.youtube.com/watch?v=EFvI8B6nU84 (comedy value)
The reason I ask is that I've been working on an ITB setup for a while now, and the s2 head would seem to be better suited as the spark plug is located on top of the head, not under the manifold as in the 8v.
My aim is not power so much as a free-revving, responsive 944. Think hachiroku
http://www.youtube.com/watch?v=EFvI8B6nU84 (comedy value)
06-01-2011, 12:33 PM
#2
Rainman
Rennlist Member
Rennlist Member
Head won't have enough clearance with those pistons. As for swapping in the pistons, there may be a problem with the 2.7 crank/rod/piston pin setup compared to the piston pin location of the S2/968 piston.
That said, if you want revvability, making the rotating bits lighter will be the best way to do it...a 16v head won't make the car rev better, maybe just support higher revving...
That said, if you want revvability, making the rotating bits lighter will be the best way to do it...a 16v head won't make the car rev better, maybe just support higher revving...
06-01-2011, 12:49 PM
#3
Three Wheelin'
16v head together with ITB's makes much more power compared to 8v. If you stay NA, I would take S2 head as the port size is a bit smaller and suits better to stock rev range. Stock S2 pistons doesn't cost a kidney also and you don't need new rods.
06-01-2011, 07:31 PM
#4
Racer
Thread Starter
Right, thanks for that. S2 pistons or 968 pistons and head assembly on the shopping list. May swap for the 2.7 parts when ready to proceed. I'll need to look at what changes need to be made to the pulleys etc first, whether I go Variocam too.
V2 - I do plan to reduce rotating weight in the next phase, but the aim here is to sort the breathing first, ditch the AFM (rogue tuning kit, possibly) and modernise the ignition.
V2 - I do plan to reduce rotating weight in the next phase, but the aim here is to sort the breathing first, ditch the AFM (rogue tuning kit, possibly) and modernise the ignition.
06-02-2011, 05:10 AM
#5
RL Community Team
Rennlist Member
Rennlist Member
2.7 pistons won't work with the 16v head, not only is the CR too high but the valves will probably hit the pistons.
I think all rods are the exact same physical dimensions except for weight.
making it rev-happy will involve opening up the engine, buying lots of expensive parts and machine work, etc. You could spend less and save time and just buy a 3.0L engine - plenty of responsiveness.
I think all rods are the exact same physical dimensions except for weight.
making it rev-happy will involve opening up the engine, buying lots of expensive parts and machine work, etc. You could spend less and save time and just buy a 3.0L engine - plenty of responsiveness.
06-02-2011, 06:00 AM
#6
Racer
Thread Starter
Hmm, the 2.7 head is worth a bit. I figured 2.7 head plus pistons for S2 or 968 head and pistons might be cost-neutral. I'm not sure what challenges there will be in the plumbing and belts yet. That might yet change my mind.
The rest will be piece-by-piece DIY. Bike throttles, modified Jetta coil-on-plug, a variable intake controlled by arduino, and much much more up my sleeve.
The other plan is a cheap 968 import from Japan for parts. But crashed cars are few and far between and the rest are just far too good (and expensive) to pick up for parts. There might be something out there... but I'm making do for now.
Perhaps someone on the big-displacement turbo thang will just swap me the 2.7 for a used 3.0???
The rest will be piece-by-piece DIY. Bike throttles, modified Jetta coil-on-plug, a variable intake controlled by arduino, and much much more up my sleeve.
The other plan is a cheap 968 import from Japan for parts. But crashed cars are few and far between and the rest are just far too good (and expensive) to pick up for parts. There might be something out there... but I'm making do for now.
Perhaps someone on the big-displacement turbo thang will just swap me the 2.7 for a used 3.0???
06-02-2011, 12:22 PM
#7
Burning Brakes
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Location: Montreal, Quebec, Canada
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the 16v heads are harder to come by and therefore costly to purchase. So don't think you will be cost-neutral unless you ignore the cash you will have to pull from your pocket.
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06-02-2011, 12:32 PM
#8
Burning Brakes
The 2.7 heads and S2 heads are comparable in price. The valves are much more expensive on the 2.7 head though. You are basically building an S motor which can be had for the cost of one of these heads....
06-02-2011, 10:34 PM
#10
Racer
Thread Starter
I'm pretty confident I could clean up and ebay the head (current prices are around $950), valves, cam, pistons etc from the 2.7 separately and then repeat the process in reverse buying the S2 bits. Maybe I'd end up reaching in my pocket, maybe not.
I just don't want to take that long about it!
The motor would have the bigger bore, plus the ITBs would give more power than the S, and leave open the option to go to a 968 crank/ light rods at a later stage for the full 3.0.
Anyhow, the original question seems to have been answered well - it is possible, but pistons need to be switched too.
