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914World.com _ 914World Garage _ Rebuild question - reuse 2.0 Mahle pistons?

Posted by: stevegm Oct 16 2016, 03:19 PM

I am getting ready to rebuild a 2.0 liter four, which happens to have Mahle pistons and cylinders. I know Mahles are really good, and it seems like they would be better than most aftermarket P&C. So, assuming they are in good condition, is it recommended to reuse them? If so, just use new rings? Has anybody here reused theirs in a full rebuild?

This engine is being built for durability for One Lap of America. Suggestions? I know AA P&C have had mixed reviews. If it is not recommended that the Mahles be reused, what is recommended?

Posted by: injunmort Oct 16 2016, 03:43 PM

if they are undamaged, i would reuse them and re ring. having said that, i would measure very carefully bore and piston/wall clearance. if within spec you should be golden.

Posted by: Mblizzard Oct 16 2016, 03:45 PM

Steve I am sure there are many here that are much smarter than I am, but if there are no issues with the Mahle P&Cs there is no way I would replace them. Ring those bad boys and run them!

Posted by: Rand Oct 16 2016, 03:50 PM

I figure re-usable is determined by the specs. Can't judge it on general chat. I'd want each piece to be measured and know it's in spec.

Posted by: porschetub Oct 16 2016, 06:10 PM

Get the ring lands carefully measured ,wear on the outside of the pistons is usually very obvious to the eye,yep they are great pistons so if good you can get the barrels honed and pistons reringed ,get the best rings you can buy and you will be golden

Posted by: SKL1 Oct 16 2016, 06:22 PM

I rebuilt my '73 2.0 a couple years ago. It had about 70K miles on it. P/C's looked fine. Used new rings, bearings etc. Worked out fine. I too figured even with 70K miles they were better than most aftermarket stuff.

Posted by: porschetub Oct 17 2016, 02:45 AM

,next question why did Mahle stop making kits out of Brazil for T4 and 911 motors ,find it hard to see why,huge demand still and they just STOPPED,maybe someone knows cause I find it odd.
I used this stuff for years and no problems,not on T4's but on T1's never had an issue so why are the good old days better???
So now we have a mix of Chinese componants and USA made parts to get it right and supply the market .

Posted by: KeithVonLaws Oct 17 2016, 02:59 AM

I have reused pistons and cylinders . Pay close attention to cylinder wear as others have noted. I would use a deglazing hone on the Bores. And if your going to clean your pistons.... never glass bead or sand blast the ring grooves or ring lands. I am going to rering a 1.8 here soon myself for my Sons car.... Good luck

Posted by: moorepower Oct 19 2016, 08:21 AM

Never glass bead pistons period. Lokk at one after glass beading with a magnified lense. The glass breaks and imbeds in the piston.