JE Pistons
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kos11-12 (04-27-2021)
#17
Nordschleife Master
The problem isn't just piston manufacture, it is the design of the piston itself, and companies like CP and Omega (good ones at that) have options and work with you in designing a piston. So 1/2 the issue is the manufacture, the othe 1/2 is the person placing the order. How has he designed the piston. Is the piston cam profile built for longevity or performance, what rings are used, how is the squish area designed. All of these affect the performance of the piston. Our 3.6 pistons produce more power than say a Mahle 3.8RS piston.
#18
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Stock 964 Head Chamber Volume?
Well, I jumped! Getting the 3.8L JE's and new Nickies, despite some very well grounded differences of opinion here on RL. I have searched through and through RL, Pelican, 911UK, PCA, and others for help on this decision and it is by no means black and white. Half drove myself nuts over it - you can overexamine things and render yourself unable to make a decision, which is just about where I was.
The primary points which teetered me in this direction were:
1) JE's change to a Porsche forging for these pistons around 2007.
2) A belief that most/all of noted past problems with JE's were due to mismatching with not-ideally-compatible cylinders. This could have resulted in cold engine piston slap for pistons/sleeves which were correctly sized to accomodate the differential expansion. Or it could have resulted in seizing of the piston for those sets which were not properly clearanced, perhaps leading to wrist pin boss failures.
3) The many emails and telcons with Don at EBS and Charles at LN Engineering, who have both been patient, very responsive, informative, and completely professional about the differences of opinion out there about their products.
Please understand that I am only offering the most objective information I could find, and I do not expect all people to agree with me. I am trying to avoid posting any opinion of mine as if it were the absolutely correct or undeniably the best approach. I recognize that my 911 knowledge is very slim in comparison to many of those on this forum. My only interest here is in posting some fair information which might be useful to some other RL'ers. I hope it is.
Cheers.
Does anyone know what the head chamber volume is for the stock 964 head? I believe it to be 90 cc but am not sure. Thanks.
The primary points which teetered me in this direction were:
1) JE's change to a Porsche forging for these pistons around 2007.
2) A belief that most/all of noted past problems with JE's were due to mismatching with not-ideally-compatible cylinders. This could have resulted in cold engine piston slap for pistons/sleeves which were correctly sized to accomodate the differential expansion. Or it could have resulted in seizing of the piston for those sets which were not properly clearanced, perhaps leading to wrist pin boss failures.
3) The many emails and telcons with Don at EBS and Charles at LN Engineering, who have both been patient, very responsive, informative, and completely professional about the differences of opinion out there about their products.
Please understand that I am only offering the most objective information I could find, and I do not expect all people to agree with me. I am trying to avoid posting any opinion of mine as if it were the absolutely correct or undeniably the best approach. I recognize that my 911 knowledge is very slim in comparison to many of those on this forum. My only interest here is in posting some fair information which might be useful to some other RL'ers. I hope it is.
Cheers.
Does anyone know what the head chamber volume is for the stock 964 head? I believe it to be 90 cc but am not sure. Thanks.
Last edited by 92silver964; 07-15-2010 at 03:05 PM. Reason: forgot to ask about head volume
#24
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PS- lived in "Bawlmer" after college - had a great time there.
Cheers
#25
I am having it done by Taylor Chapman at the German Auto Group in Springfield VA. He is great to work with and I am very confident the finished product will meet or exceed my expectations. There have been a few delays but I am hopeful to have it back by the end of December. To say "I can't wait" is putting it very mildly. I will be sure to post the results with photos, etc.
PS- lived in "Bawlmer" after college - had a great time there.
Cheers
PS- lived in "Bawlmer" after college - had a great time there.
Cheers
-Ed
#26
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Sure thing - look forward to it.
#27
Drifting
How is your build going -- did you go LN or EBS?
I'm in the same boat.
rebuilding a RSR race/track engine.
the engine had 102mm mahle jugs and ross pistons -- the engine
was pulled by PO due to piston slap.
the jugs look and mic fine, but the pistons were scuffed
and the clearance was 0.006"
m
I'm in the same boat.
rebuilding a RSR race/track engine.
the engine had 102mm mahle jugs and ross pistons -- the engine
was pulled by PO due to piston slap.
the jugs look and mic fine, but the pistons were scuffed
and the clearance was 0.006"
m
#29
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Just got back from my first post-rebuild checkout by the mechanic - Taylor Chapman who now has his own place, Chapman AutoWerks in Sterling VA. Very nice place and he's got a good partner (Andrew). Made me realize how much the place he was in before was choking him (G.A.G., pun intended). I highly recommend him to anyone in the area. He's really a good guy on top of being an excellent 911 mechanic.
Car is running great - I got the go ahead to push it beyond 4000 rpm! I've been so well behaved, and it's killing me. 800 miles since the rebuild and the oil out looked good. No leaks too! Took a fun ride home. For those of you in the Washington DC area, I'll pass along a fun spot. Clara Barton Parkway inbound from the beltway; there's a spot where you are kind of under the outbound lane, with a wall to your left and an overhand above. If you like to hear your 964 in full throttle, it's a great "chamber".
I am still trying to get my rebuild bio finished and will post then. Cheers.
#30
Drifting
Any updates?
I went with a 3.6L long block -- but I still have the 3.8 engine in crate waiting in the wings should I decide to build it up.
mike
I went with a 3.6L long block -- but I still have the 3.8 engine in crate waiting in the wings should I decide to build it up.
mike