GregBBRD

Yes. I send 2 pistons with every block....and they actually seem to measure them....at least they come back with numbers on them!

GregBBRD

It never has seemed like putting the "factory" iron plating on the pistons should be all that difficult. In the early days, we tried to see if Mahle would put that coating on a "custom" piston of our own design, but they claimed it was a "process" that was licensed through the automobile manufacturer and that they could not do this.

Then came the "Ferroprint"......might as well have pissed on it, instead of pissing on me.

mark kibort

when you "tossed" the Mahle pistons, was that a set that they modified or coated for you , or the stock 968pistons that seem to work well in the alusil bores. I thougth if you got a stock 968piston and found someone that could do the proper SI process, you were good.

All that work for piston coating failure! Seems so lame that they cant get it right.

mk

GregBBRD

They were actually an "off the shelf" set of pistons for a Big Block Chevy, I'm building. Figured the coating would fall off and then they would slap, too.

ptuomov

For a car manufacturer with large runs, there's a very large difference between Alusil and Nikasil cost in favor of Alusil. Large enough that it's a major decision to go Nikasil in terms of higher cost.

For someone building a custom engine, I was under the impression that boring and honing Alusil cylinders competently was not much cheaper. 928 Motorsports quotes $1600 for boring to piston spec and Nikasil plating for the block. That's $200 per cylinder. Alusil seems like it's in the $100+ range according to Erkka, although maybe it's cheaper here in the US.

I guess my point is, and I believe you agree, that once you have a professional building a custom engine, it's a slam dunk obvious decision to go Nikasil. Nikasil allows one to use the best available pistons, the cost difference is small in the grand scheme of things, Nikasil wears less (although since Alusil wears so little this is almost irrelevant), Nikasil retains oil better, and Nikasil also transfers heat better from the piston. Downsides for Nikasil are that it didn't handle high-sulfur fuel well 15 years ago and chrome plated rings are risky to use. (Some of this came from memory and some from http://bmw8.us/Nikasil%20and%20Alusi...%20smaller.pdf)

One case in which Alusil makes perfect sense to me is if the bores, rings, and pistons are perfectly fine and can be reused. Don't fix what's not broken.

BC

I should double check if there is an issue with nikasil and ethanol. I wouldn't think so since nickel is the material electrically plated to aluminum to make it safe with ethanol.

ptuomov

It was my understanding that the reason why they don't want to do the old-style Ferrocoat on pistons anymore is that it's much more expensive because of the environmental protection adn cleaning costs. This is a rumor from my memory, so take it for what it's worth. If true, I am guessing that one could start a custom piston manufacturer in Brazil, Ferrocoat like in the good old times, and dump it all to Amazon after that. Business idea, there.

Appropos nothing, for the general public consumption, here's some random info on reconditioning aluminum blocks: http://ciftheplayer.free.fr/photosje...804-02_WEB.pdf

FlyingDog

Mahle still makes pistons with the original process. They just do not do custom/motorsport pistons that way. They do make a lot of MB/BMW alusil compatible pistons with the original process. I've always wondered if there was an MB/BMW piston size that would work well for a 928.

RKD in OKC

That is not what bothered me. We were friends and I was getting parts at cost and enough discount on labor that I didn't mind being on the bleeding edge of research and development. It was kinda fun being a part of the process. It was when they told me they weren't working on "customer cars" any more and didn't have time to even look my car after the gasket burned that I got pissed and sold the car to a guy that parted it out.

Vilhuer

Probably not. At least all BMW Alusil engines seem to have way too small bore for out purposes. Largest oversize of them is smaller than stock 4.5L 95mm 928 IIRR.

FlyingDog

I just googled to find the answer and one of the first results was you saying this last year.

The 4.9L S62 engine (E39 M5, Ascari ZK1, Ascari A10) was the largest I found in my quick search. 94mm bore and 89mm stroke, so close to a 4.5l 928 block/bore with a GTS crank.

I found a few pages saying that the repair manual recommended oversize for a Mercedes M119 is 102mm and there are factory pistons available. Apparently Brabus uses them to bump the 6.0L version to 6.5L with a modified crank and shorter rods. I didn't find anything for 103 or 104mm.

GregBBRD

I'd guess that the odds of finding another manufacter's piston that has the right size, the correct pin location and size, with the correct combustion chamber shape and volume, and be compatible with Alusil is less than the odds of winning the lottery.

BC

Greg - I found that website that I wrote about earlier. This is not the exact process I was speaking to the rep about, but its the idea that the aluminum could be coated with a ferrous coating just like it has now. The only issue I guess is making sure the ring lands are NOT coated.

http://www.enduracoatings.com/coatin...el-plating.php

BC

I don't have all the info required to fill this out, but it may help us along:

http://www.enduracoatings.com/coating-questionnaire.php

BC

A thread with good pics (last page) of what can go wrong, and post 28 has a pic of the wossners I was referring to.