Technical 4032 vs 2618 forged piston alloy?
- Thread starter IQraceworks
- Start date
So far I've really happy I went with the Mahle 2618 pistons. Nice and quite at startup. Couldn't be happeir with them! Glad I went with them.
Pictures from your install, fitment tolerances etc? More info would be awesome from first hand.
Check out this thread I made about my engine build….lots of good info, pics, specs.
https://www.spoolstreet.com/threads/4-cylinder-is-dead…any-ideas-as-to-what-caused-the-failure.8959/
From what I remember (without digging up all of my notes), my piston to cylinder wall clearance on the Mahle pistols was between .0027”-.0030” on my stock 84mm bores. The bores were in good shape, so no machine work was needed. I ran a 220g ball hone through the cylinders to get the proper 30-60deg cross-hatch pattern to seat the moly rings, and that was it. Mahle says you want to run somewhere between .0025”-.0033” for the piston to wall clearance, so my actual clearances (.0027-.0030) I got were about as good as I could ask for.
Based off of Mahles recommendations, I set my ring gaps to .020” on the top ring, and .022” on the second ring. (my oem ring gaps were around .009”-.0011”…no wonder the piston ringland broke)
Install was pretty straight forward, just like any other engine I’ve built over the years. The engine idles smooth as silk, and it very quiet at idle….just like it was with the OEM pistons and rods in it.
I’ve got around 250miles on the breakin oil, and everything is running great. I’ve done some light pulls to seat the rings, and just to put some time on things. I need to dump the break-in oil this weekend and put some fresh 5w-40 in it with a new filters.
I’m pretty happy with how everything turned out. I’m glad I spent a little more on the Mahle pistons vs. the cheaper 4032 pistons like Kingtec and other places make. Everything I’ve read about the 2618 alloy pretty much says that when it comes to high-performance boosted applications, there is nothing better. Sure, 4032 will work….but 2618 is just “the best” choice. Also, from what I have found, the process of producing the 2618 alloy has been refined and improved over the years. Todays 2618 is stronger than it was 15+ years ago. I’m sure there is a reason Mahle makes all of their N54 pistons out of 2618.
