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Registered User
Join Date: Jul 2017
Posts: 1
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Replacing pistons & cylinders, need advice
Looking to replace the pistons & cylinders on my 3.0 and having a hard time spending 3500.00 on the Mahle set. Especially considering its just a air cooled 3.0 engine. Either way does anyone have a recommendations on a few manufactures of good guilty at decent price.
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New-ish 911SC Targa Owner
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Not sure what the reasons are for replacing so this might not be applicable. I had my 6 cylinders (they were allusil) replated with nikisil for $990. i reused the allusil pistons with new rings made for nikisil cylinders. The rings were like $125 I think. i used EBS in Reno for this work. not sure who actually did the replating though. US Chrome maybe?
If i was to redo it, I would have had the cyl bored to 98mm first and used aftermarket JE or CP slugs with 10:1 cr.
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'83 Targa 300k w/ freshened 3.0 with 930/52 case# 6770540 ARP and Raceware hardware - AEM Infinity 506, Triumph T595 ITBs, B&B headers, Dynomax muff, Fidanza FW, Alum PP-203whp |
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Registered
Join Date: May 2004
Location: Boulder, Colorado
Posts: 7,275
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Pamp's sounds like a really good approach. The ring lands are the wear surfaces on a piston, so if they check out the pistons are good to reuse. Nikasilling Alusils done by the usual suspects works fine. Big savings. Now that we know the Alusil pistons will work fine with Nikasil as long as the right rings are used, maybe someone will even purchase my 6 Alusils (the cylinders got Nikasiled for a race motor).
This way you have the proper piston dome shape for the CIS. I'm unsure if any of the aftermarket pistons can replicate this. J&E's are cast or forged with a sort of universal hemispherical dome, then the valve pockets are machined and the top sliced off to hit a CR target. At least that is how the ones I have seen are made. If you have replaced the CIS, then a lot of aftermarket options are open. A stock 3.0 has all the power anyone needs for highway driving, or for DE for that matter. Anything more is strictly avocational. Disposable income, by definition, is yours to decide how to dispose of it. |
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Under the radar
Join Date: May 2007
Location: Fortuna, CA. On the Lost Coast near the Emerald Triangle
Posts: 7,129
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Quote:
We are assuming your cylinders are K&S and worn out?
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Gordon ___________________________________ '71 911 Coupe 3,0L outlawed #56 PCA Redwood Region, GGR, NASA, Speed SF Trackrash's Garage :: My Garage |
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Registered
Join Date: Mar 2004
Location: Windsor, CT
Posts: 2,119
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So Kobel-Schmidt pistons can run in a Nicasil coated, Alusil cylinder bore?
If so, they’d be a better fit to the cylinders than the JE pistons. Better ring life. |
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Registered
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if replating ensure you get the correct surface roughness. Several report never ending oil consumption and/or premature wear of rings. If doing again I would have used nickies or mahles. Delivered through someone with a quality control system in place. Cheap can be expensive
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80SC (ex California) |
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