one of the PRI Tech article series, this one speaks to coatings applied to engine components.
I knew of coating piston skirts, somewhat to reduce friction, but mainly to provide a second layer of scuff protection.
I had not heard of coating piston skirts to allow, for example, a standard size piston to be used in place of an OS piston.

https://www.bluetoad.com/publication/?i ... &ver=html5

_________________
Doo Ron Ron and the Duke of Earl are friends of mine.....
https://www.youtube.com/watch?v=uX8Nj8ABEI8

Interesting. I am thinking I might try some main/rod bearing coatings sometime...

Lou

_________________
Home of Slant6-powered fun machines since 1988

Doc did some of this a while ago.. when I find the thread I will post.


Greg

_________________
http://www.youtube.com/hyperpack

http://www.slantsix.org/forum/viewtopic ... it=Coating


I think this is the thread... but The pictures from 2008 are now gone

Greg

_________________
http://www.youtube.com/hyperpack

The race shop I worked at swore by Microblue. It was for bearings and such.

_________________
Official Cookie and Mater Tormentor.

agreed, anti-friction coatings are not new,

what the article that is linked in the first posting deals with, is using a coating to build out a piston skirt .020 + to allow one to use again
a piston that was no longer useable due to an over bore on a crankcase.

To explain it further:
if you have a used set of slant six forged pistons but the block really needs an over bore to freshen it, instead of buying another
set of forged pistons to match the new bore size, it is possible to have the skirts built up on the existing pistons to match the over bore put in the crankcase.
Doc writes some good stuff but that is not what he was writing about in 2008.

For me, the concept of building piston skirts out to match an overbore was new information.

_________________
Doo Ron Ron and the Duke of Earl are friends of mine.....
https://www.youtube.com/watch?v=uX8Nj8ABEI8

I see he really doesn't reccomend building pistons up more than a few thousandths. You can, but he doesn't like it. I'm guessing he does it on builds where new pistons might be unobtainable.

_________________
Official Cookie and Mater Tormentor.

Read the article posted at the link in the first post.
They speak of building up piston skirts over .020
That is 10 times more than a few thou.
There is a photo of a diesel piston with multiple dyno
and strip runs with no visible issues at the coated skirt area.

_________________
Doo Ron Ron and the Duke of Earl are friends of mine.....
https://www.youtube.com/watch?v=uX8Nj8ABEI8

PolyDyn is close to me and I've had lots of stuff coated by them. The thing is...their coatings are very thin...thinner than normal paint. I'd say paper thin, but paper is thicker. So if anyone is using a coating to make a piston thicker, it must be some sort of coating intended to be thick. In other words, normal Teflon and lube-carrying coatings are very thin.

I read it John. I didn't say he couldn't do it, I said he didn't recommend it.

_________________
Official Cookie and Mater Tormentor.

Okay..

Thanks different coatings for different purposes.

I am in the market for coatings for long life bearings!


Greg

_________________
http://www.youtube.com/hyperpack

I am intrigued by the coating of short skirt pistons so you can tighten clearances and stabilize the rocking. That could open up more piston choices.

_________________
Official Cookie and Mater Tormentor.

and there you go,,
maybe save some used scuffed pistons and find homes for slightly undersized new ones....

_________________
Doo Ron Ron and the Duke of Earl are friends of mine.....
https://www.youtube.com/watch?v=uX8Nj8ABEI8