Pelican Parts Forums

Pelican Parts Forums (http://forums.pelicanparts.com/)
-   911 Engine Rebuilding Forum (http://forums.pelicanparts.com/911-engine-rebuilding-forum/)
-   -   Replacing pistons & cylinders, need advice (http://forums.pelicanparts.com/911-engine-rebuilding-forum/1033360-replacing-pistons-cylinders-need-advice.html)

Pauls 911 06-28-2019 06:49 AM

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.

pampadori 06-28-2019 07:40 AM

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.

Walt Fricke 06-28-2019 10:10 AM

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.

Trackrash 06-28-2019 03:14 PM

Quote:

Originally Posted by Pauls 911 (Post 10506284)
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.

There are options as mentioned. You can search here and find a number of examples of 3,0s being rebuilt and what piston, cylinder options exist.

We are assuming your cylinders are K&S and worn out?

VFR750 06-30-2019 05:37 PM

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.

trond 07-01-2019 04:14 AM

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


All times are GMT -8. The time now is 05:45 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2025, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2025 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website


DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.