bearing coatings?

[Moriartyhlms]

Hello, I’m in the middle of rebuilding a 964 engine. I have noticed on IG that some high-end engine shops are having main bearings (and rod bearings?) coated with Dow Dry Film, Calico, or PC-3. Anybody have insight on this? Worth doing? Which is best? Cost? Where to get it done (I’m in LA)?
Thanks
-Sam

[Adrock]

I was reading some info about this recently on the general 911 forum - sorry - I dont have time to search them out at the moment... but, there's a few threads there.
From what I was reading it appears to be fairly cheap too.

On the other hand - you would think if it was worth doing the bearing factories would do this as standard - as part of their production? Possibly overkill?

I read some people doing it in the hope to make up some thickness on bearings that they received that were too thin - usually from Glyco.

I just picked up ACL bearings for my rod big ends - as well as GT3 bearings for my mains. Both looked and measured perfect.

[MBruns]

Coatings are worth doing if you have the room for proper bearing clearance, any coating worth doing is going to add .0004 per shell and if the crank is strong std and rods are on the low limit with coated bearings its a problem. I like to finish grind the crank after the coating and rod is measured/assembled to set the oil clearance I want.
Mike Bruns

[MBruns]

I use H.M. Elliott Coatings, they are in Moresville, NC 844-816-6801
I imagine there is someone on the west coast but HM has a quick turn around.
Mike Bruns

[Tippy]

Cheap insurance in case you don't cross drill your crank.

Supposedly, you can run for a short amount of time without oil pressure under load.

[Ryan H]

Originally Posted by Moriartyhlms

Hello, I’m in the middle of rebuilding a 964 engine. I have noticed on IG that some high-end engine shops are having main bearings (and rod bearings?) coated with Dow Dry Film, Calico, or PC-3. Anybody have insight on this? Worth doing? Which is best? Cost? Where to get it done (I’m in LA)?
Thanks
-Sam

Hey Sam,

I'm pretty sure Chris at Turbokraft sells bearings that he has coated and they are very reasonable.

Ryan

[MST0118]

I've used Calico for standard main bearings. They were quick and cost was reasonable.

['76 911S 3.0]

What is WPC?

This process micro shot peens the surface to provide microscopic dimples for oil to reside in. Next rebuild is having all the bearings and piston skirts treated by WPC. The nice thing is it is not a coating so tolerances do not change with this process. They are also located in Los Angeles, so local to you.

[jpnovak]

I admit to being a big fan of engine coatings for harsh environments. To me coatings should be applied as part of a complete package. Dry film lubes (DFL) and Thermal Barrier coatings (TBC) can reduce friction and increase combustion efficiency when used properly.

I say go for it.

When you get down to the fundamentals all of the suppliers and vendors have about the same process and results.

[Mark Henry]

Originally Posted by jpnovak

I admit to being a big fan of engine coatings for harsh environments. To me coatings should be applied as part of a complete package. Dry film lubes (DFL) and Thermal Barrier coatings (TBC) can reduce friction and increase combustion efficiency when used properly.

I say go for it.

When you get down to the fundamentals all of the suppliers and vendors have about the same process and results.

We do DLF and ceramic coatings in-house.
I highly recommend the DFL, I've even done several builds using good used bearings that I DFL coated. Perfect treatment for used piston skirts and uncoated new.
Ceramic IMO really only needed in higher performance builds, high CR & HP.

The cost, the coating is cheap, it's mostly labour. There's fair bit of prepwork, clean, process, bake, then polish . Everything has to be spotlessly OCD clean.
I agree the coatings, whoever you use, are basically the same.

[Jeff Alton]

Mark,

What DFL coating brand are you applying?

Cheers

[jpnovak]

I too install in house on all my builds. I use TechLine Coatings. They have a water based and solvent based coatings. Yes, the materials are cheap. The labor to properly prep parts is where the cost is. I charge actual time or prep surcharge if used parts. The process is something like this: (media blast, clean, prebake, clean, blast , clean, warm, coat, clean, burnish) you get the idea. Time at each step.

In a build with full parts coatings the list would look something like this. I agree that the more stress you put on the engine (compression, displacement, rpm range, etc) the more the benefit of the coatings from safety margin, friction reduction and heat management.

Examples of parts for DFL:
Main bearings
Layshaft bearings
Rod bearings
rocker shafts
Cam lobes and journals
piston skirts
wrist pins
Basically any part that has friction.
I have also DFL coated cam sprockets, Intermediate shaft gears, etc
Oh, and don't forget transmission parts.

TBC coated parts include:
Cylinder head chambers
Exhaust ports
Exhaust valves
Piston crowns
Valve faces.
I typically do not coat the intake ports. I think a little heat helps in vaporization.

[Mark Henry]

Techline as well, I usually only coat the softer metal of two wear surfaces.
I find the coating doesn't last long on pins, shafts, valve stems, etc, but on the babbit bearing, bronze bushing, etc, it holds up very well.

[Jeff Alton]

Thanks