924Board.org

Modoc · Posted: Sat Dec 31, 2005 3:07 am Post subject: 51 head on a 24s

ok so everyone talks about a 931 head on a 924 what about a 951 head on a 924s? anything keeping someone from doing that? anyone tried it before... I've got a place where I could possibly get the head what do you guys think ? worth it?
_________________
Proud owner of
'88 924s - Sold
'01 ML430
'97 Honda Civic

special-tool · Joined: 08 Jul 2005 Posts: 64 Location: Bethel, Ct.

Not worth it. Slightly different port shape - which might actually HURT you.

Get a wideband, SMT6 and a Milledge cam and you will see some significant power gains.

I have had the wideband on my 87 924S and the fuel tuning was not really that good. It was up around 14 too much especially without the cat.
_________________
951 566/485 HP/TQ at the wheels - pump gas
924S GTR conversion project
Honda 250R- PWK 35mm flat slide, 205 static, Boyesen, Wiseco, DG front/back, Uni, 14/42,

CBass · Joined: 03 Nov 2002 Posts: 2807 Location: Vancouver, Canada

Why not just go 3.0 DOHC instead? The reason for going to a 931 head from a NA is because the 924 head is junk in at least a half dozen different ways.

Terrible ports, terrible combustion chamber, terrible cooling etc.

The 944 head is no Formula 1 piece, but there's nothing really WRONG with it. If I was to look at swapping bits and pieces in a 944/924S, I'd look at the 3.0 DOHC engine. 240hp in 968 trim, a little tuning can get you more, the sky is the limit. I don't think a 3.0 DOHC head swap would result in a favourable compression ratio with a 2.5 8v 944 bottom end however.
_________________
'81 931 in various states of assembly

special-tool · Joined: 08 Jul 2005 Posts: 64 Location: Bethel, Ct.

Good idea - but the 968 and the S2 head do not fit on the 2.5 block.
The 968 is by far the best 4 cyl Porsche head ever made.
If you wanted a DOHC head on a 2.5 block, you need the 2.5 liter S head - that is a direct fit.

_________________
951 566/485 HP/TQ at the wheels - pump gas
924S GTR conversion project
Honda 250R- PWK 35mm flat slide, 205 static, Boyesen, Wiseco, DG front/back, Uni, 14/42,

Kevin D · Joined: 28 Jul 2005 Posts: 152 Location: Boise, ID

Best solution is to just get the whole 3L and 6sp put in the 924. Bolts right in.

_________________
'88 924S 3L 6sp RedRat
'92 Duc 900ss
'02 Duc 998 Carbon
'72 RD 350

Modoc · Posted: Mon Feb 13, 2006 2:57 pm Post subject:

good to know

next question, price quote on that please? how much did it cost you?
_________________
Proud owner of
'88 924s - Sold
'01 ML430
'97 Honda Civic

Kevin D · Joined: 28 Jul 2005 Posts: 152 Location: Boise, ID

Actually, I bought it from the guy that did it and then decided to just buy a 997, so cost was never really an issue for him. Judging from the reciepts I've gone through, this isn't an economical option. He paid around $7000 for the motor and tranny (with tt) delivered and has about 100 hours into the swap. The mechanics were a straight bolt in, no custom adaptors/mounts needed. It's hard to tell exactly where the 924 ends and the 968 begins. He put in a larger 944 radiator and the 968 brain. I have some funky wiring diagraming, but beyond that it seems a simple, if not economical swap. I still have to figure out the tach (simple) and the cruise control (not too important). In the meantime, it's a fun sleeper. I keep in contact with the previous owner and his mechanic/buddy here, so I'd be glad to get better details if needed, but I doubt this is really the best solution to finding power.
_________________
'88 924S 3L 6sp RedRat
'92 Duc 900ss
'02 Duc 998 Carbon
'72 RD 350

Llamaguy · Joined: 02 Jul 2003 Posts: 711 Location: Indiana

doesn't the 951 head have some funky ports, something about coming out the wrong side of the head or something.
_________________
1987 924S Guards Red
1997 Suzuki Tl1000 Supersport