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Hi Gang, I'm getting ready for an engine rebuild, and I need to decide between Mahle and carrillo pistons. In the end, price difference between the two is roughly 3k. Anyone have any input?
CP makes some spectacular pistons! They really have a handle on the barreling of the piston. I also love the way the remove weight from under the dome by removing excess material in the same contour (option on custom pistons).
What’s going to make of break the CP piston in the Porsche application is finding someone who has spec’d it out properly for the air cooled 911. The off the shelf CP piston leaves a LOT to be desired. It also needs to be made from 4032 high silicon forging NOT 2618.
Another challenge you’ll face is honing/boring existing cylinders. There’s a very slight taper to account for unequal expansion of the cylinders. Bore/hone that out and you’re asking for trouble.
Check with Steve at Rennsport, Charles at LN and Jeff at Rothsport. One of those 3 should have a custom CP piston spec’d for your needs. IMHO if done right it’s a better way to go than the heavy Mahle pistons. The likelihood of getting it all wrong is really high so the safe and easy bet is factory P&C’s.
CP makes some spectacular pistons! They really have a handle on the barreling of the piston. I also love the way the remove weight from under the dome by removing excess material in the same contour (option on custom pistons).
What’s going to make of break the CP piston in the Porsche application is finding someone who has spec’d it out properly for the air cooled 911. The off the shelf CP piston leaves a LOT to be desired. It also needs to be made from 4032 high silicon forging NOT 2618.
Another challenge you’ll face is honing/boring existing cylinders. There’s a very slight taper to account for unequal expansion of the cylinders. Bore/hone that out and you’re asking for trouble.
Check with Steve at Rennsport, Charles at LN and Jeff at Rothsport. One of those 3 should have a custom CP piston spec’d for your needs. IMHO if done right it’s a better way to go than the heavy Mahle pistons. The likelihood of getting it all wrong is really high so the safe and easy bet is factory P&C’s.
Thank you for this. Exactly the type of insight I'm looking for.
You might also take a gander across Pond and talk with 9M. He’s customized a great deal of the bits that make these beauts faster. Don’t forget the gearbox as well.....
The CP's for sale at LN are all 2618....anyone know if CP makes a 102mm piston out of 4032? Marin is right, 4032 is what you want for a NA engine.
The LN nickies with 2618 piston maybe a good combination. Billet aluminum expands and contract a great deal. Same is true for 2618 piston. Charles the owner of LN is a sharp guy so if anyone thought this through he did. Worth a conversation with him. Overall most will never need the upside strengths of 2618 pistons. The downsides of them are greater expansion rates so they need to be fit looser in cylinder when cold. It’s this sloppiness that kills em with each cold start cycle. In a race car they make more sense. In a street car that make for a much shorter engine refresh cycle. I would ask Charles about that. Also research issues with Nickies. I read one guy had trouble with peeling nickelsel (spelling?) when running hot.
In an ideal world I would design a piston with the latest X forging style made of 4032 with Anti detonation grooves and more material between upper ring land and surface. That high silicon forging is similar to the mahle 401 material.
Still with all that being said the mahle motorsports 3.8 P&C’s are the safest bet. When holding the cylinders next to factory ones the improved quality of casting is readily apparent. If going that route I would try and lighten the pistons by removing excess material under the dome. No simple or easy task to get that right. I do know Protomotive has cut down stock 993 piston to lower compression on turbo builds. The fact they survive added power with less material on top of piston is telling to me. There’s a LOT of excess weight/material up there!
The LN nickies with 2618 piston maybe a good combination. Billet aluminum expands and contract a great deal. Same is true for 2618 piston. Charles the owner of LN is a sharp guy so if anyone thought this through he did. Worth a conversation with him. Overall most will never need the upside strengths of 2618 pistons. The downsides of them are greater expansion rates so they need to be fit looser in cylinder when cold. It’s this sloppiness that kills em with each cold start cycle. In a race car they make more sense. In a street car that make for a much shorter engine refresh cycle. I would ask Charles about that. Also research issues with Nickies. I read one guy had trouble with peeling nickelsel (spelling?) when running hot.
In an ideal world I would design a piston with the latest X forging style made of 4032 with Anti detonation grooves and more material between upper ring land and surface. That high silicon forging is similar to the mahle 401 material.
Still with all that being said the mahle motorsports 3.8 P&C’s are the safest bet. When holding the cylinders next to factory ones the improved quality of casting is readily apparent. If going that route I would try and lighten the pistons by removing excess material under the dome. No simple or easy task to get that right. I do know Protomotive has cut down stock 993 piston to lower compression on turbo builds. The fact they survive added power with less material on top of piston is telling to me. There’s a LOT of excess weight/material up there!
A 4032 piston in our Nickies cylinder will result in piston slap and wear out the pistons and rings prematurely. We're partnered with Mahle Motorsports where Mahle no longer offers cylinders, paired with Mahle pistons made from 2618 alloys, like JE or CP Pistons, running clearances similar to a 4032 in a factory Mahle cylinder which utilizes a high silicon content to reduce cylinder expansion. The 2618 alloy is the correct alloy to be used with our Nickies cylinder.
We've been supplying cylinders to the Porsche aftermarket for almost 20 years. Failure are far and few between - we can build a near bulletproof cylinder, but some still manage to damage them, either through poor turning or botched assembly, which we have no control over.
There are no issues with NSC plating adhesion with our cylinders, nor noisy operation, when the pistons are properly configured. Millennium provides a lifetime warranty against defects in plating like adhesion and that's something we've never had to deal with.
Most of the sets of cylinders we sell are without pistons and many builders spec out their own designs, so it is up to them to get it right.
The other bits on the top end... cams and valves?
Intake improvements... throttle body and runners?
Exhaust improvements... headers?
Stronger bottom end... crank, rods, and oil sump?
ECU tune?
A 4032 piston in our Nickies cylinder will result in piston slap and wear out the pistons and rings prematurely. We're partnered with Mahle Motorsports where Mahle no longer offers cylinders, paired with Mahle pistons made from 2618 alloys, like JE or CP Pistons, running clearances similar to a 4032 in a factory Mahle cylinder which utilizes a high silicon content to reduce cylinder expansion. The 2618 alloy is the correct alloy to be used with our Nickies cylinder.
We've been supplying cylinders to the Porsche aftermarket for almost 20 years. Failure are far and few between - we can build a near bulletproof cylinder, but some still manage to damage them, either through poor turning or botched assembly, which we have no control over.
There are no issues with NSC plating adhesion with our cylinders, nor noisy operation, when the pistons are properly configured. Millennium provides a lifetime warranty against defects in plating like adhesion and that's something we've never had to deal with.
Most of the sets of cylinders we sell are without pistons and many builders spec out their own designs, so it is up to them to get it right.
how did they manage to make gt3 engines run up to 9000 rpm?
Which kind of material Porsche did use for their GT3 pistons?
A nice informed man that built 911 air cooled racing engine for 35 years told me that all the rsr he saw running above 7500 rpm had an engine failure, sooner or later.
he clearly told me hat the problem of those engines is represented by the pistons weight...there is no point of making a high performance but reliable air cooled engine (like the GT3 engine is) without finding the right solution to this problem.
The rest might be expensive (for sure), but already there.
the key for high performance is enhancing the rpms GT3 alike.
once one has been able archiving that, the other issue I suppose would be the management of heads temperature, which is what Porsche claimed it was the main reason to move towards water cooling, and in fact the 959 engine is not a surprise had mixed cooling system.
how did they manage to make gt3 engines run up to 9000 rpm?
Which kind of material Porsche did use for their GT3 pistons?
A nice informed man that built 911 air cooled racing engine for 35 years told me that all the rsr he saw running above 7500 rpm had an engine failure, sooner or later.
he clearly told me hat the problem of those engines is represented by the pistons weight...there is no point of making a high performance but reliable air cooled engine (like the GT3 engine is) without finding the right solution to this problem.
The rest might be expensive (for sure), but already there.
the key for high performance is enhancing the rpms GT3 alike.
once one has been able archiving that, the other issue I suppose would be the management of heads temperature, which is what Porsche claimed it was the main reason to move towards water cooling, and in fact the 959 engine is not a surprise had mixed cooling system.
the argument itself is very fascinating to me
Mahle Motorsports makes pistons both out of 4032 and 2618. The 4032 alloy is used for Porsche applications when paired with a cast Mahle cylinder. Their 2618 alloy is used in the Nickies+Mahle Motorsports kits.
With regards to the GT3, CP-Carrillo makes those pistons for Porsche now, however the forging and piston design is different from CP's full round or X forgings and I would presume they are using some sort of 4032 alloy to allow clearances less than .001" cold.
11-06-2019, 07:28 PM
3.8 Build: Mahle vs. CP-Carrillo pistons
