So the Hartech 3.0 is basically a standard 968 block assy with shaved pistons, and a 2.7 head bolted on. there's been a couple of complete 968 engines on ebay for £2k recently, 2.7 heads usually £250+ when you can find one, a set of forged turbo rods £150ish, get lucky with the cams/head on the 968 engine and you've got a future upgrade path or money back potential, or as someone who had been there and done all that and then some advised me, keep the turbo engine and convert to 2.8.
3.0 944 turbo
- Thread starter pauly
- Start date
That was a good way to do it, I'm not really motivated to pull the fit engine out of my car and throw thousands at it for the sake of more low down torque, I could probably add a half decent TVR 400SE wedge to my garage for the same money. Though I still keep a lookout for a bargain S2/968 bottom end and a 2.7 head, put it on an engine stand and I'd have a nice garage ornament [
].
u63af
Member
I am in the process of collecting parts to make a 3.0
So far I have a 2.7 head, need a good set of 944 t exhaust valves if anyone can help?
I was under the impression that the rods needed for the 3.0 were longer but I must be incorrect. So if I get a set of 944 t forged rods, they will pretty much work spot on in the 3.0 other than needing slight machining etc? Do they fit straight onto 968 crank?
I take it I would need 968 pistons as the 944t are too narrow?
Are you guys using existing liners or getting steel liners instead?
So far I have a 2.7 head, need a good set of 944 t exhaust valves if anyone can help?
I was under the impression that the rods needed for the 3.0 were longer but I must be incorrect. So if I get a set of 944 t forged rods, they will pretty much work spot on in the 3.0 other than needing slight machining etc? Do they fit straight onto 968 crank?
I take it I would need 968 pistons as the 944t are too narrow?
Are you guys using existing liners or getting steel liners instead?
DivineE
New member
The rods are the same size for all. No machining required. You will require 3.0 crank for S2/968, S2/968 block, 2.7 head (to match up with oil ways on 3.0 block) or you can use a turbo head to keep the ceramic ports/valves and modify the one oil way that is in the wrong place. This might possibly be a good idea as the single biggest problem with the conversion is the 3.0 blocks ability to cope with increased heat.
You don't need liners, you can use the standard block but if you do want steel liners (better for high power applications) Jon9xx or Hartech can supply them.
You can use S2, 968 or custom pistons. Various people can get you custom pistons (usually through JE Pistons and they have kept the CAD drawings for 6 or more 3.0 turbo designs, so you can order direct if you have faith in others getting the spec right). Hartech used the 968 pistons for their car and machined out the dish because the crown of the 968 piston is thicker than the S2 piston so it's better suited to the turbo application.
I would also recommend the 968 block because the piston squirters will help with cooling.
You can use a standard 3.0 water pump but it would be sensible to copy Hartech and put the rad valve closer to the block so it opens at a lower system temperature (again to keep temperature under control). You can use the standard S2 head gasket but of the two manufacturers who produce this item one is better than the other as it has thicker fire rings (I'm afraid I cant remember the name of the one you want off the top of my head).
Any more questions please do not hesitate to ask
Wossner pistons seem to be the best option for custom pistons these days especially if you want to use them in an Alusil block. Also just to correct the above in that it is the coolant passage/ jacket that needs to be modified if you use a 951 head, not the oil way. Make sure you get the right piston rings to work in an Alusil block if you do go for custom pistons and do not install sleeves. You will probably be better off buying new exhaust valves as they are not as expensive as the intake valves. I do not believe that 3.0 blocks do not cope with the heat any better or worse than a 944 block. There are many people running 3.0 blocks with good results and the heat can be controlled with the right combination of intercooling, water cooling and oil cooling. The only difference is that the 968 block relies slightly more on oil cooling due to the different flow of coolant around the cylinders and the use of oil squirters to cool the underside of the pistons instead. The factory block is fine without liners if you get the right pistons.
It seems the water jacket is shallower on the 2.7 block and I think Baz Hart said on S2 engines there can be signs of localised over heating at the base of the cylinders, I wonder if the 2.5 block with liners would be thermally superior ?, but then there's the issue of sealing the water jacket from the crankcase. I'm not sure there is a right way to do a road 3.0, perhaps if someone does 100k on one it will prove what works long term.
TTM
Well-known member
The blue 968TS in the UK had done 100k km (60k miles) when it was bought from Germany.
Though I have had some small but persistent issues since the beginning with mine, some being my fault, others being not, they did not prevent me from doing 16k miles without blowing it up.
The right way to build a 3.0 is the same way as to build a 2.5 - either build it the way Porsche did, underpowered but unburstable, and it will go to the moon and back, or take the chance to make it a decent performer and risk having issues. It's as simple as that.
Though I have had some small but persistent issues since the beginning with mine, some being my fault, others being not, they did not prevent me from doing 16k miles without blowing it up.
The right way to build a 3.0 is the same way as to build a 2.5 - either build it the way Porsche did, underpowered but unburstable, and it will go to the moon and back, or take the chance to make it a decent performer and risk having issues. It's as simple as that.
I understand the difference in the water jacket etc, but Porsche still used the 3.0 block for their turbo cars including the RS so they did not see any problem with it. I am with Thom on this one, build it the way the factory did it, but as you increase the power expect to re-engineer it on the way if you want 100% reliability. I think there are more plus points to the 3.0 block than negatives. On a 968 block you have siamesed cylinder walls and webbed reinforcement in the casting all making for a stronger block.
Its a good solution but not a true 3.0. Depends what you want but certainly nothing wrong with it from an engineering point of view. Andrew Sweetnam built a very nice 2.8 that made some strong numbers a few years back that left many a fast car wondering which way it went on track.
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