DLC Coating Internals

BramanteCummins

BramanteCummins

ADD maniac
Joined
Nov 1, 2012
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636
Finally back at it with my build. Decided on pistons and now looking into coatings for the skirts. Thats when DLC came into my mind.

For those that don't know, DLC is an acronym meaning "Diamond-Like Carbon". DLC is basically carbon hardened to the point until is is almost to diamond state. It has super low friction and stiction properties. It also is extremely hard making it ultra resistant to abrasion.

Concerns are if it will stay bonded at high temps and how would it compare to other coatings. Im also thinking of getting other parts DLC'd like the cam, tappets, rocker surfaces, and valve stems.

Thoughts and inputs?
 
The guy we use for powder coating, he coated a bunch of his parts. Needless to say he coated the cam, and considering what the cam goes through, the only parts that the coating had come off of, were of course the lobes. But everything else was pretty damn nice looking still.
 
Oldestof11, I was a bit of a meathead when it came to pumps and tolerances required. Since then I've actually worked in a pump shop and gained a lot of knowledge. Looking at that thread, wow who's the idiot haha

Murphy, what was the application? Sled puller, DD? How long was it in there for?
 
Daily Driver, 5.9L CR. It had about 25,000 miles on it when it was pulled apart. Previous motor builder didn't believe in Plasti-Gauge and munched a couple mains, and a couple rod bearings.
 
Doh! I was hurrying to work when I read and searched. Never looked at the names.
 
Is this going to be some >1000hp competition truck?

Or is it just a science project?

There's a boatload of trucks without these coatings that run great. While the technology is cool, you've not stated why you need these coatings. If you're just going to put that 551Ve on it and play around, then I'd say don't bother. 702hp vs 700?
 
750 max is my goal, I figure if drag is reduced then it makes it that much easier, no?

But yes this is my science project daily driver. Can't wait to actually get it done
 
It's a $/hp thing.....if you pick up 5% with coatings, I think you'd be doing well.

The right injectors / cam / turbo can easily eclipse that.
 
Dont coat any parts that contact each other.........such as lifter face and cam lobe....No good.
And use tool steel cam......NOT cast, although at lower RPM it may work.
 
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One would think where the coating is lower friction than the metal coated, having all surfaces coated would be even better. As far as the cast vs Tool steel cam, are you saying if the lifter were to get coated the cast would wear out?
 
There are huge differences in DLC coatings and needs of the material. Most companies and Nascar teams that tried DLC on cam and lifters had issues with flaking. I dont recall why, but if only one surface was coated everything got along fine. Some companies require tool steel cams, some dont. Most want the cam RA around 2, if I recall.
Nissan uses DLC on some OEM stuff and they also have a special oil for it. I read a paper on it once and there results surpassed most others by a good margin.
 
I did not know DLC had different forms. For this build I'll go old fashioned then and save the experimentation for the much cheaper and easier to repair dirtbikes. Thanks for the info, matty169
 
I've been using Cerakote coatings and have had pretty good luck with it. But I do my own painting, powder and ceramic coating, so the cost is minimal. On my current build, the piston tops, valves and combustion chambers got the gold piston coating. Then the piston skirts, tappets and top half of the rod bearings got Micro Slick. I only coat one of the wear surfaces too. One of their 4 oz bottles is enough to coat everything. Total cost for the engine was $70. Plus, I always start out with fresh grit in the sandblaster for critical parts, so that was another $25.

Needless to say, my turbo housings and manifold are ceramic coated inside and out. For them I use an insulating coating and then turbine coating on top of that. Works pretty well also.
 
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