Currently having my pistons, heads and intake thermo coated hoping more than anything to keep the heat factor of my LTx engine under control. While I’m at it, the pistons are being friction coated and the person doing the coating is pushing me to do the bearings also.

Guess my problem is with the oil film.. I can’t see how coating the bearings would help. Also if you were to coat the bearing, why not do the crank also??

My gut feeling tells me I’m probably wasting money having the pistons friction coated and it would be an absolute waste to coat the bearings. Can someone prove me wrong??

Ain’t that much money and I’m up for it if it helps, but then again…. It’s a lot of Big Macks n fries I could be sucking down instead. Shoot, maybe even a decent happy hour.

 

You should get the bearings coated just to keep away from those Big Macs 'n fries...
But Happy Hour is anutter story!
Anywho, AFAIK, the coated bearings are more of an insurance policy vs. an actual performance increasing item. The crank is actually spinning on a thin film of oil within the bearings halves. And the coating is there to provide lubricity in case the oil film "goes away." It gives the engine a chance of survival between the time the bearings lose lube and the time the engine is shut down. The one "high end" engine I have built in my lifetime was a bored+stroked AMC 401, and AMCs have pretty crappy oiling systems. So, I had all the bearings coated. I never had a problem where the coating was needed, but then again I had peace of mind if anything did happen.

 

I would do the bearings also. Look at companies like More Performance, they have all of their bearings coated. I am thinking about having my pistons and bearings done. Who is doing yours and about how much is it costing for the pistons if you don't mind me asking?

 

Friction= Engine = less HP

I know its not going to HELP persay on the bearings since the crank SHOULD never come into contact with the bearings, but in extreme circumstances like say some spray or a dropped gear that went too far, like 4-1 going 70mph, stuff like that where the rotating assembly shocks so hard that it might hit the bearing, it will protect the crank journals from being scuffed. Also, id imagine if you didnt run it for a few months the oil would probably run off the mains and be without oil for a split second, maybe some insurance there.

The pistons would defintely be worth it if its in the budget. I wouldnt really be too worried about thermal coatings IMO, my 381 with forged slugs ran at like 170* not a degree over EVER, not even prolonged idle, and thats with no coating, just elec pump and 160stat. Now if you are using the coating for the other purpose, being trying to keep more than the 33% of heat lost through the cooling system in the cylinder to increase pressure, then thats a good thing, as long as you dont run into detonation which shouldnt be a problem.

 

I was under the impression that the 401 could not be bored to any useful extent. How far did you go, and what was the final CI.

 

A local shop is coating my heads and I haven't even gotten a price on the pistons as I special ordered some Lunati pistons and Lunati screwed up the first order so I'm still a week or so away from getting them.

I have a place in Houston who will do the pistons for $35.00 each and if the local shop is out of line, I'll just ship down to them. The local shop is right next to the shop doing the additional porting so It's more of a convenience fact or than anything.

 

Big difference between being on the Lake where your at and the hot plains of Dallas. With the air on mine will run hotter than I like, plus it's 12.3 to 1 compression 398ci motor.

Could be a waste...... but I guess that how you find out. Not that much money.

Thanks everyone!

 

As much money as a complete build costs, I would rather be on the safe side and have my stuff coated, for me anyway with a forced induction engine. I am going to get a price on my piston tops and side skirts along with the bearings from Ariborn Coatings.

 

I'd say go for it. At the least, it should decrease start-up wear.
Does the coating retain oil? How thick will it be?

 

The car sits in my garage and I only take it out in nice weather either for joy rides or this year, to race in a series. Whaa..... maybe started less than 100-150 times in a year.

Cold start wear is not an issue and nor is a failure of my oiling system. I want power! Can't see how it would help considering oil films and also no one addressed the issue: If a little is good......more is better. Why not coat the crank journals?? Camshafts. etc. etc.

 

My car sits most of the year and only gets driven about 300 miles in that time. It hasn't been started now in a few months. I have always used Mobile 1 so it hasn't been much of an issue but I figure I might as well do it.

 

That's why you need the coating. The oil seeps out from between the crank and the bearings during the week and you start it dry on Saturday. The coating will hold a film of oil on the bearings.
Coatings go on one side only because you only need one side to hold the oil. Then the oil just slips over the metal on the other surface.

 

I wonder instead of getting coated bearings...a pre-luber of some sort? I mean if you really only concerned about startups and a lack of oil for that fraction of a second...eh?

 

Yeah, Morosos accumulator is pretty cool, always thought it would be a pain in the *** to use, but I saw an install on it on some tv show and its extremely easy and great insurance. Just prime it the first time with compressed air then the oil pressure recharges it everytime you shut the engine off and you have whatever oil pressure ready before you start it.