I have Kolbenschmidt. Should I be bummed?
 

I just found out from my topend shop that I have Kolbenschmidt-- not Mahle-- P&C on my SC. What's the downside for a street car?

I found the same thing for my track car, and I'm putting them back in. I pulled the P&C's together without removing the P's from the C's. I had no compression or oil consumption problems before the teardown. I'm just replacing bearings, rod bolts, head studs, etc., before the racing season. Worst case, I'll be forced to replace them later. At least the rest will be done.

I think it depends on the reason you are rebuilding. If it is just a top end job, say for Dilavar head studs like mine and your leak down was good then I do not see a problem doing as Zoanas and I did and remove the P&C's as a unit and put them back on. If the motor had bad leakdown or greater than say 150K miles I would source new P&C's

The top end was because of 7 broken head studs. My car only has 69000 miles. I am the original owner.

Had mine re-ringed and the cylinders refinished. All is well.

I remember reading some downsides to the KS pistons, but it was so long ago I'm not sure I am remembering correctly. It seems that for a variety of reasons, though, most people prefer Mahle. I think one of the issues with KS was sometimes they tend to be more noisy than Mahle, i.e. piston slap type noise, esp. during warmup?

Maybe try doing a search on this board for more info, there may be something.

There is a big thread on Mahle v. KS... in the engine building forum.. Read what you want into it. I found out I have KS in my SC and this thing runs really well for 140k miles, but I feel like I am bummed too because of what I have read. Thing is, if you come from a 944 or 928 background, all the blocks are Alusil, and those guys have been dealing with this stuff forever. I was one of those guys too. There is much to learn on the Rennlist forums about Alusil. This is one occasion that the waterpumpers can give back to the aircooled boys.

I have successfully reringed a 944 and a 951 that were really fantastic runners. In my eyes the jury is still out.... when the time comes I will be considering reringing my KS if they are in spec.

I had and rerang them with great luck until I turbo charged it and over boosted. i would put them back in and don't worry about it