LR: given an experience like that, and that nearly all great running motors get along without coatings, I can see why you feel that way after an experience like that. I am not sure that coatings do any good, it may all be voodoo. The logic seems compelling, but reality/data trumps logic EVERY SINGLE TIME.

Rich

 

Get a set and check them the one that I get from the local speed parts will dial guage at least .001 smaller than the same brg uncoated.
That has been my experience and I know if they don't make 1 thousands under brgs for an application I can get coated to tighten the clearance.

 

Yea,they seem to fine small amounts of HP with the coatings know but ya now the saying burned once-- burned twice = my fault.

 

Dang, that is fast for a Mustang!

Now before I get 30 people telling me how fast some are let me help you out.... that was a JOKE!

I have never used a coated bearing but I am all ears. I'd like to see independent data that shows some benefit if anyone has it.

In my mind, a hydrostatic bearing doesn't need a coating.... unless that coating helps the oil wedge in some way. Maybe a gain in bearing life when you look at cold start conditions but how much?

As for piston coatings, I use Swain Gold Coat and have never had a problem. I remember back in the late 80's when guys were having flaking problems and the like... just as LR described. I stayed away from them then up til the time I saw a Swain coated piston that had survived numerous trips in a Pro Mod motor. I was sold. I've used their coating on exhaust valves, exhaust ports and headers with zero problems. Highly recommended if you have the extra money to spend. Only after putting it in all the right places first though.

-Mindgame

 

The Swain stuff THAT good?
Might have to try some,if they stand behind their stuff.
Piston tops would probably be as far as I go. That's for some of these people that like to live on the danger side of NO2.They would rather lean a shot down rather than spend to get a larger system.
Needless to say they don't live on that side very long.

 

I bet Rich would put in a vote for them as well... I know I do.

The coated bearings from them as well I'm a fan of, not cheap but for startup or times when you might have a oil problem they are worth it. Keith Dorton kinda sold me on this. You don't need them all the time so KISS definately applies here.

Bret

 

So would my application benefit from them or no? I am rebearing-ing(is taht a word) my engine due to the pick up comming uncovered and would like to give it all the help I can in this department.

1racerdude, you edited you comment a couple of post back, it origanlly said something about the P rod bearings being grooved, I looked a couple of places and didn't see where they said they we grooved, just the P series mains. The statement below is why I would think I would use these bearings. Sorry if I am overthinking this, because I am.

Use the P-series rods where extremely high RPM's cause severe rod bore close in. This is typically indicated by nearly full parting line to parting line shaft contact with bearings having less eccentricity. Use P-series mains where higher eccentricity is desired to narrow bearing contact patterns and to provide increased oiling to rod bearings. Rod bearing oil starvation is typically indicated by polishing and smearing of the bearing surface possibly accompanied by discoloration predominantly concentrated at the axial center of the bearings.

 

Swain is where I go for the gold crown coating, sounds like Bret likes them too. The prices have gone way up lately. Their original TBC (thermal barrier coating) is up to $24.50/piston. That's $196 if you have a V-8 and decide to coat all eight pistons*. The top-of-the-line "Gold Coat"" is now a whopping $42.50/ That's $340/set. So, if you "go for the gold" and use JE (my fav pistons), good rings and pins, you are talking $1,200+ for a set of pistons!!! Get the skirts coated for another $120, add in some shipping and maybe taxes and you approach $1,500. The bearings are pretty cheap, $41.50/set (rods or mains).

As MG said, put it in the right places. Usually, spending it somewhere will have a better bang for the buck. But if you need it, you need it. The two motors I am currently involved in have very different needs. The crowns in the Camaro, with boost and N20, needs all the help they can get. Piston failure is a common way for a high boost motor to go out. The race car has a mild NA BBC turning just 6,500rpm, no need for coating the crowns or anything else there.

Think about what you are doing before randomly throwing $$$ at it. This is not a great stategy (voice of experience). But don't overthink. If you don't already know about the "P" bearings, you probably don't need them.

Rich




*jk

 

I'll keep this simple.

I use exclusively Clevite rod/main bearings, Use Durabond cam, coated on the race motor stuff. Yes the clearances have to be massaged in most cases.

I don't do much with coatings on crowns and chambers, I have seen as recently as 2 years ago coatings coming off on some high EGT motors, I'm talking 2300* egt diesel pullers.

 

Ok I think we have beat the coated horse to death now. I am still between the H's and P's

A little excerp from the link that Rich posted

Use H-series bearings with crankshafts that have oversize fillets and where engines run in the medium to high RPM range. H-Series bearings should be used if contact patterns obtained with P-series parts are too narrow. Contact pattern should ideally cover 2/3 to 3/4 of the bearing surface.

How do you figure this contact patch? It seems to me like to biggest reason for these H bearings is to run the cranks with oversize fillets, is this true? Also I looked in summit and the only H series mains they offered were 3/4 or full groove. Would these still be the ones I am looking for or am I not seeing the halfs? The article listed also says P series mains come in full groove but I can only find them in half? This is getting worse on my end, what would be my main distration to running the P's in stead of the H's? Thanks for you patience guys I just want to do this once with the right bearings.