3 Liter Turbo Registry
#841
Addict
Rennlist Member
Rennlist Member
I don't think it would have any positive effect.. 16v chamber is so nice and symmetric, it would be sin to leave that pad on the piston.
Im exploring options for exhaust valves. I trust Duke that stockers work, but would be nice to use inconel or some other more turbo friendly stuff.
Im exploring options for exhaust valves. I trust Duke that stockers work, but would be nice to use inconel or some other more turbo friendly stuff.
#842
Rainman
Rennlist Member
Rennlist Member
Shopping for cylinder heads to put on top of a 3.0-3.1L shortblock...
the question is...to go 8v, or to go the full 16v...?
fabrication not a problem where needed...
buy-in cost of the heads and machine work about the same.
this will be the big mean supercharged engine, so "low-end torque" will be in good supply. 16v has +30% airflow out of the box, or more, but can it fool the smog guy (blower will come off of course )?
maybe just do one and then the other later.
the question is...to go 8v, or to go the full 16v...?
fabrication not a problem where needed...
buy-in cost of the heads and machine work about the same.
this will be the big mean supercharged engine, so "low-end torque" will be in good supply. 16v has +30% airflow out of the box, or more, but can it fool the smog guy (blower will come off of course )?
maybe just do one and then the other later.
#843
Rainman
Rennlist Member
Rennlist Member
this arrived in the mail yesterday, with pistons to match
sleeved 3.0 block and JE pistons...bore approx 104.75mm.
thinking of staying simple and just putting 951 rods on a 3.0 crank for the bottom end. my power goals are "modest" and i dont care about RPM that much, so boat-anchor con rods are OK.
i still have a 968 crank to grind on if i need more cubes someday.
unsure if i will put a 2.7 head on top or just a modified 944/951 head.
sleeved 3.0 block and JE pistons...bore approx 104.75mm.
thinking of staying simple and just putting 951 rods on a 3.0 crank for the bottom end. my power goals are "modest" and i dont care about RPM that much, so boat-anchor con rods are OK.
i still have a 968 crank to grind on if i need more cubes someday.
unsure if i will put a 2.7 head on top or just a modified 944/951 head.
#844
Three Wheelin'
You can see how much Lindsey charges by going to the head section and goin through the price / recipe selections
The 951 stock components are good for 400 hp so in a well tuned motor these rods would work for your 3 liter if your ok with that goal. Bottom line is you could use 1983 forged NA rods as long as your build and tune hold up!
As far as S2 stock piston crown thickness I can't answer that but I do know there thicker than 968 units and heavier. My first 3 liter turbo motor in 2005 I used those same S2 pistons had them fly cut for 2.7 valves and coated on face and skirts they ran fine on 16 psi with a k26/6.5 cheater wheel turbo had 350 hp and lots of torque made full boost bye 2600 that was a fun car.
The 951 stock components are good for 400 hp so in a well tuned motor these rods would work for your 3 liter if your ok with that goal. Bottom line is you could use 1983 forged NA rods as long as your build and tune hold up!
As far as S2 stock piston crown thickness I can't answer that but I do know there thicker than 968 units and heavier. My first 3 liter turbo motor in 2005 I used those same S2 pistons had them fly cut for 2.7 valves and coated on face and skirts they ran fine on 16 psi with a k26/6.5 cheater wheel turbo had 350 hp and lots of torque made full boost bye 2600 that was a fun car.
#845
Rainman
Rennlist Member
Rennlist Member
recipe is a good word...tempting goodies they offer!
thanks for the tip.
400hp is my goal, don't really see much point in going beyond that in a street car, and that is pretty much maxing out the M90 supercharger.
even if its a bit less than that i'll be happy.
the reason for considering a 3.0 vs a regular 2.5 is that i want the power at minimum boost level...e85 is available, but i want to try to run this thing on 91 octane if i can get away with it.
20% more displacement means the same airflow at ~20% less boost (backpressure), means lower temperatures, means lower octane requirement...
thanks for the tip.
400hp is my goal, don't really see much point in going beyond that in a street car, and that is pretty much maxing out the M90 supercharger.
even if its a bit less than that i'll be happy.
the reason for considering a 3.0 vs a regular 2.5 is that i want the power at minimum boost level...e85 is available, but i want to try to run this thing on 91 octane if i can get away with it.
20% more displacement means the same airflow at ~20% less boost (backpressure), means lower temperatures, means lower octane requirement...
#846
Addict
Rennlist Member
Rennlist Member
Its gonna be a tight fit..
#847
To come
I hope to be joining the club soon.
I'm in the UK and currently have a 1994 968 Sport which has been lavished throughout it's ownership but particularly since I bought it in 2010 (i'm the second owner).
I already have lots of upgrades from Pole Positions, Club Sport rear shelf, KW Suspension and lots of other bits and pieces. It's a third car and I do track it.
I'm still learning about the 3.0l Turbo options, i'm at the start of the journey having just sourced a 2.7 head and another 968 3.0l block so that I can keep my car running whilst all that is built.
I'm not a mechanic myself so will be getting a local specialist to build and fit the engine, probably EMC in Birmingham. They use their own custom spec forged pistons with sprayed iron skirts and ceramic tops plus forged rods of course. They steel wet line the block, I know not everyone agrees with the steel part so welcome thoughts.
I'm currently looking into the various options regarding cams and actual turbo's as well as sourcing some of the other bits i'll need.
Look forward to the journey and learning from you guys who have done it already.
I'm in the UK and currently have a 1994 968 Sport which has been lavished throughout it's ownership but particularly since I bought it in 2010 (i'm the second owner).
I already have lots of upgrades from Pole Positions, Club Sport rear shelf, KW Suspension and lots of other bits and pieces. It's a third car and I do track it.
I'm still learning about the 3.0l Turbo options, i'm at the start of the journey having just sourced a 2.7 head and another 968 3.0l block so that I can keep my car running whilst all that is built.
I'm not a mechanic myself so will be getting a local specialist to build and fit the engine, probably EMC in Birmingham. They use their own custom spec forged pistons with sprayed iron skirts and ceramic tops plus forged rods of course. They steel wet line the block, I know not everyone agrees with the steel part so welcome thoughts.
I'm currently looking into the various options regarding cams and actual turbo's as well as sourcing some of the other bits i'll need.
Look forward to the journey and learning from you guys who have done it already.
#848
Three Wheelin'
Wild full custom 3 liter twin cam reversed head 968 full race build
Can you say 3,000 hrs of design and hours spent on this build whats your guess on how many hours?
http://www.worldtimeattack.com/index...p-968-porsche/
http://www.worldtimeattack.com/index...p-968-porsche/
#850
Rennlist Member
Big it up for Thom!! Well done on such untroubled driving with your 3ltr beastie!
#851
Addict
Rennlist Member
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Looks like it is built right. Congrats. What pistons/bores are you runing Thom?
#852
Rennlist Member
Thread Starter
#853
Thanks. The spec of the engine on the first page is still actual apart from the turbo (current one is a GTX3576R 0.82, so if Shawn could update this...).
The tach mod is done by a local guy who rebuilds gauge clusters.
The tach mod is done by a local guy who rebuilds gauge clusters.
#854
Addict
Rennlist Member
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Alusil/Andial. Nice. Do you know what piston to wall clearance and ring gap clearance you have? Yours would definitely make a good reference point.