When I did it more then 15 years ago it was still a bit of a niche but I think these days it will cost less then a set of new of these cast iron wear faces + seals and labour to open up and reseal the engine.

Ill ask some companies around what it would cost to coat one insert then it can be back to back compared to a straight nitrided one.

 

I'd be interested to hear just which process you finish up using to cope with the temperatures. Wikipedia links to 7 broad categories of DLC and there are many proprietary offerings out there.

 

A 33mm cam follower coated in DLC was ~ $Au70 a pop before shipping both ways and GST around 2012 from one of the usual suppliers in the UK, with raw material, energy and everything else significantly increasing in cost world wide, wouldn't get the hopes up too high prices have come down since....... certainly a lot more area to coat on multiple plate faces! Back then at least iirc, the advice was it could handle around 350C.

There was somebody doing it in Melbourne for endmills and so forth.

 

Ive sent a inquiry out, lets see what they say.

The plates are 6.05 to 6.06 mm thick and the recess in the housing is 6.00. So before DLC I will lap 0.02mm off to be 100% there is no more white later from the nitriding. We had it at work with cam finger followers for a 9k rpm V8. They got DLC after nitriding and after just a couple of hours the coating started to flake off. In the end now they get isotropic finished before DLC to remove the withe layer and since then the coating stays on properly.

the plates as they come from Billetpro seem to have a similar hardness as factory housings, judged by my trusty ali express hardness test files. The file labelled w 60 HRC doesnt scratch it and the one w 65 does.

@rx72c when you had the significant wear after short use, where they also the Billetpro plates? Did you use a file or something to get a rough idea if there was any sort of nitriding done?

 

Not sure why I would bother when there are better billet plate manufacturers out there.
Billet by pac, I have engines that are 4+ years old and going strong.
My current billet boss engine is 18 months old and is going great as well.

 

What sort of use you do to the engine w the pac plates? From the pictures I find it looks like the coolant just passes from the outer circumference like it does in a rotor housing. Does it get enough cooling near the plug area of the side face? Id assume especially for intermediate housing this could be problematic for a boosted engine running for long periods of time like on circuit racing. For a 7 second drag car running methanol this would probably be less if a concern..