18:1 pistons on ebay, these are Mahle, oem pistons and come complete with rings. These are quality pistons. They are listed for 425.00 for standard compression and add 150.00 for 18:1. Considering when I built my engine I paid 1250.00 for just the pistons and another 250.00 for the rings, check this out.http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=33623&item=7953211682&rd=1:grd:

Chances are there will be broken rings when received. Never had good luck with the rings installed when shipping.

I don't think Mahle has 18:1 available at this time. My regular price for std pistons is less.

Mahle is NOT the OEM brand piston...

Kennedy,
true mahle are not gm's oem supplier but they are an oem supplier of others. What brand of pistons do you sell? I have had some real bad luck with some after market pistons, crowns not anodized and pistons disintergrated(silvolite to be exact):(

Whatever 18:1s they are selling, they are not Mahle, or at least not unmodified Mahle.

I have the std Mahle units and wouldn't touch anything without a steel ring carrier.

The 18:1 pistons that I bought from Penninsular a few years back were factory GM blanks that had the piston pin location offset to reduce compression. I believe that is what the Mahles are also, but I haven't had a set in my hot little hand so I am just speculating.:)

Those are Penn's Bohn pistons, oem 6.5, from Germany, along with the Bosch injectors.

Still cannot decide on the reduced crown heighth, or the relieved crown, to reduce C\R.

The Bohn's would retain the original hard-anodize surface - NASA developed the technology for the Shuttle, to survive re-entry heat.
Doesn't conduct heat thru-surface, but distributes heat evenly across surface - good stuff for a turbocharged Diesel piston.
But - the reduced-heighth Bohns expose the upper cylinder wall to combustion temperatures early in the cycle, where combustion results in a 'jet' of hi-temp flame-front pressure out of the pre-cup port, and across the piston crown to the opposite wall of the cylinder.

Cummins and others use the relieved-crown type, shielding the cylinder walls across TDC, where total combustion occurs in that fully dished crown.

Gm\Opel is\was the German division, FYI.

I looked through some of my used stuff and found a few Zollner pistons mixed in with a bunch of Bohn's. GM used both for the early years of the 6.2. I couldn't tell the difference in failure rates. If you stuff a broken-off glo-plug tip through the top of a piston, it doesn't make much difference who built it!

check out this web site www.diesel-direct.com (http://www.diesel-direct.com)