944 S head prepared for 2.5liter turbo engine
07-09-2014, 11:20 AM
#65
07-09-2014, 11:37 AM
#67
Three Wheelin'
Thread Starter
Nothing special: stock 2.5liter crank and block, RARST factory forged rods, machined 951 pistons, stainless steel valves, S2 cams, ceramic coated exhaust ports (inside the head) and exhaust manifold (outside), Holset HE341 turbocharger (9 cm2 turbine, compressor is good to ~500-550 hp), custom intake manifold, custom intercooler made from two 951 cores, Siemens 870cc injectors, VEMS ECU, Spec Stage 4 clutch, S2 tranny with Torsen diff.
Will be resting in this '83 924 (has 951 brakes, alloy arms, Koni Yellows etc):
Will be resting in this '83 924 (has 951 brakes, alloy arms, Koni Yellows etc):
07-09-2014, 12:32 PM
#68
Rainman
Rennlist Member
Rennlist Member
should be a rocketship.
that engine is beautiful...nice work. will be interested to see how the pistons hold up with the machining done to them.
that turbo looks like a good fit for this motor, with the front-facing outlet should help with plumbing...
that engine is beautiful...nice work. will be interested to see how the pistons hold up with the machining done to them.
that turbo looks like a good fit for this motor, with the front-facing outlet should help with plumbing...
07-10-2014, 04:04 AM
#70
Three Wheelin'
07-10-2014, 04:26 AM
#71
Three Wheelin'
Thread Starter
Haha, sorry Bas, missed your post.
These are from VAG FSI engines, fit well but are a bit longer than actually needed. I got them from a friend who had them laying around, these are later revisions.
But actually COP's from 6.0 W12 engines are pretty much perfect fit, did not want to buy them from the dealer for 30 euros a piece. I am a cheap guy you know and this is a budget build
In reality there is no obvious need for COP ignition but on 16v engine they look cool and since I do not aim too high power levels, these work well. A guy here in Estonia runs Audi A4 1.8T with these active COP's with ethanol and 1000+ hp and they work surprisingly well:
These are from VAG FSI engines, fit well but are a bit longer than actually needed. I got them from a friend who had them laying around, these are later revisions.
But actually COP's from 6.0 W12 engines are pretty much perfect fit, did not want to buy them from the dealer for 30 euros a piece. I am a cheap guy you know and this is a budget build
In reality there is no obvious need for COP ignition but on 16v engine they look cool and since I do not aim too high power levels, these work well. A guy here in Estonia runs Audi A4 1.8T with these active COP's with ethanol and 1000+ hp and they work surprisingly well:
07-10-2014, 04:46 AM
#72
Rennlist Member
Be interested to see what is involved when converting to 16v head on 2.5L block. Is there a restriction on bore size?
07-10-2014, 05:02 AM
#73
Three Wheelin'
Thread Starter
No, not at all as the head comes from 2.5liter 944S and has the same 100mm bore size as all 2.5liter blocks. Head bolts etc are all the same.
I am in the process of fabricating custom dual crossover pipe that will be connected right before turbine in order to have pulses separated as long as possible.
I am in the process of fabricating custom dual crossover pipe that will be connected right before turbine in order to have pulses separated as long as possible.
07-10-2014, 05:04 AM
#74
Three Wheelin'
Thread Starter
The links are dead in 1st post (domain name has changed from .ee to .org) and I cannot edit the 1st post anymore, so posting them again for reference.
Head just before installing the valves:
Combustion chamber:
Generously flowing intake port, these are quite big on Porsche 16V heads:
Ceramic coated exaust port:
And here's the head with valves installed:
Head just before installing the valves:
Combustion chamber:
Generously flowing intake port, these are quite big on Porsche 16V heads:
Ceramic coated exaust port:
And here's the head with valves installed:
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Jay Wellwood (10-14-2023)
07-10-2014, 05:20 AM
#75
Rennlist Member
I'm running 106mm pistons or near enough, in a sleeved 2.5 block. Also block is now O ring'd but I have access to a highly modified 16v S head so have considered it.