Its been a few years since we have seen the Re-intro. of the aftermarket 86 mm(1720cc) piston & cylinders. Thought this would be a good time to find out how they have performed. My thoughts would be the preferences of using O.E.cast iron Cyls rebored to accept JE pistons, as opposed to the newer AA set with cast iron liners & biral alum fins. I realize that the LN product (nickasil) cylinders are the best, but want to limit this forum to the cast iron sets avail. to date. Also interested in those who have had their cast iron cylinders rebored & nickasil plated.Cast alum. pistons vs forged, noise , wear, etc. Any & all input appreciated.
Thanks Max H
86mm 1720 cc aftermarket P&Cs
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Max Handley
- 356 Fan
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86mm 1720 cc aftermarket P&Cs
Last edited by Max Handley on Tue Apr 08, 2008 8:27 pm, edited 1 time in total.
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Cliff Murray
When I rebuilt my Speedster engine 8 years ago, I used Shasta/JE pistons and cylinders. My previous bike racing experience made me aware of how strong JE pistons are. I have not been disappointed other than the fact that one cast iron cylinder was slightly long and caused a head leak which was easily fixed by shortening the one barrel. Lesson- CHECK EVERYTHING!
That being said, I bought a car that came with a new set of Japanese cast pistons and iron barrels. I am very happy with the seal on these and there are advantages to using cast pistons in a street motor. If you are sticking under 6000rpm you can save your money and get a quieter, oil thrifty, result.
That being said, I bought a car that came with a new set of Japanese cast pistons and iron barrels. I am very happy with the seal on these and there are advantages to using cast pistons in a street motor. If you are sticking under 6000rpm you can save your money and get a quieter, oil thrifty, result.
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Charles Navarro
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Although it's getting harder and harder to find original german mahle core cast iron cylinders, it is worth the effort to bore and hone them for new high-silicon JE pistons over available cast iron alternatives. That said, as the previous poster offered, regardless of where you get your cylinders and pistons, you're the last step along the way when it comes to quality control. Question everything. Measure everything at least twice. Best to do it right the first time.
We've found at least with the 914s, that nothing beats the orignal german castings. That's the additional reason why I have gone out of my way to find the original alloy 356 cylinders, that we then strip the chrome bores out of and replate with nikasil, at a considerable savings to our Nickies cylinders. This makes a middle of the line price with an exceptional product for lower compression <9.5:1 street engines up to 1720cc, when coupled to the low-silicon JE Pistons. Same goes with the cast iron cylinders, as we've taken out of spec mahle cylinders that had been bored out previously to 86mm and we can bring them back into spec by nikasil plating the cast iron, with exceptional results. This usually provides improved ring seal and longer cylinder life do to the exceptional properties of the nikasil plating. We also surface grind the cylinders to match up the height groups, so as to perclude the chance of an un-even deck causing sealing problems as some have experienced.
If you use the 4032 forgings (high-silicon), you can run tighter piston to cylinder clearances than with the other low-silicon 2618 forgings, at least in a cast iron cylinder. Likewise, the 2618 forgings best suit an aluminum, nikasil cylinder, because of like expansion rates, allowing even tighter operation. You can run the 2618 forgings in cast iron, a bit loose, so it's a tad noisy, but in some cases it's better to use the 2618 forgings anyways because they are significantly stronger and can be machined ligher than the other forgings.
We've found at least with the 914s, that nothing beats the orignal german castings. That's the additional reason why I have gone out of my way to find the original alloy 356 cylinders, that we then strip the chrome bores out of and replate with nikasil, at a considerable savings to our Nickies cylinders. This makes a middle of the line price with an exceptional product for lower compression <9.5:1 street engines up to 1720cc, when coupled to the low-silicon JE Pistons. Same goes with the cast iron cylinders, as we've taken out of spec mahle cylinders that had been bored out previously to 86mm and we can bring them back into spec by nikasil plating the cast iron, with exceptional results. This usually provides improved ring seal and longer cylinder life do to the exceptional properties of the nikasil plating. We also surface grind the cylinders to match up the height groups, so as to perclude the chance of an un-even deck causing sealing problems as some have experienced.
If you use the 4032 forgings (high-silicon), you can run tighter piston to cylinder clearances than with the other low-silicon 2618 forgings, at least in a cast iron cylinder. Likewise, the 2618 forgings best suit an aluminum, nikasil cylinder, because of like expansion rates, allowing even tighter operation. You can run the 2618 forgings in cast iron, a bit loose, so it's a tad noisy, but in some cases it's better to use the 2618 forgings anyways because they are significantly stronger and can be machined ligher than the other forgings.
Charles L Navarro
LN Engineering
http://www.lnengineering.com
Aircooled Precision Performance
LN Engineering
http://www.lnengineering.com
Aircooled Precision Performance
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lee whistler
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Jake Raby
- 356 Fan
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I concur totally with Charles' post...
The cast iron sets currently available are made from materials different than the OE cylinders and due to this and the fact that QC is almost non existant with off shore made parts one must approach them with an objective approach.
I have seen some of the of shore made pistons and cylinders recently when doing a balance job that was sent in by a customer and the same characteristics of lack of QC were very evident in most every regard.. The pistons had ring lands that varied in radial depth greatly, they were way out of balance (7 grams!) and teh cylinder lengths varied by .003
When using these parts one MUST remember the #1 rule in engine building- NEVER ASSUME ANYTHING!
The cast iron sets currently available are made from materials different than the OE cylinders and due to this and the fact that QC is almost non existant with off shore made parts one must approach them with an objective approach.
I have seen some of the of shore made pistons and cylinders recently when doing a balance job that was sent in by a customer and the same characteristics of lack of QC were very evident in most every regard.. The pistons had ring lands that varied in radial depth greatly, they were way out of balance (7 grams!) and teh cylinder lengths varied by .003
When using these parts one MUST remember the #1 rule in engine building- NEVER ASSUME ANYTHING!