Espritv8man

Has anyone got experience of coated bearings?
I'm rebuilding a 5.5L LS6 race engine from out of a Daytona sports prototype, its for use in my Lotus Esprit silhouette doing 25 minute road course races here in the UK.
I notice Clevite do Tri Armour bearings and a firm called Calico coat Clevite bearings.
Has anyone used these ? How consistent are the coating thicknesses and do they give extra protection in extreme conditions?

Any advice much appreciated.

Simon

JL ws-6

iTrader: (50)

I run a coated bearing in my 402, I haven't taken the motor apart since ti went together, but the coating is supposed to help.

I've got over 150 passes on my motor and so far no problems, oil pressure is still great, no noise, very little material ever on the drain plug magnet.

For the cost, I would just do them, ya got nothing to lose.

FlamingChicken

iTrader: (2)

i was at the hendrick engine build contest two years ago and a rep from clevite was kinda commentating during the builds. one of the questions he was asked was about the coated bearings. he said it is just to keep your mind at ease since metal should never touch the bearing surface anyway. if it does you have more serious problems.

JL ws-6

iTrader: (50)

You're right it never should... but I'd rather have the coated bearing in there then not.

KCS

iTrader: (20)

Right, it shouldn't. But the coating is like the sacrificial layer in case something happens. Instead of the bearing spinning, it is "self clearanced".

The trick is to find a company that does a good job of actually coating the bearing. Sometimes, dirt will get caught in the coating (seen it happen) and it could change the eccintricity that is designed into the bearing which creates the oil wedge (seen it happen).

THENASCAR

iTrader: (19)

not to hijack the thread. but along the lines of coating. for my 402 build im going with clevite 77H bearings and was pretty set on having them cryo treated along with other parts. many of my transmission parts that im using on my 4l60e have been cryo-treated. this process increases the metal resistance to wear. i suppose it is technically not a coating but whats yall thoughts on this and where is a good place to get bearings coated?

Espritv8man

Thanks for the replies,

I have been in touch with Clevite, they say the clearance will reduce by 0.0006" (give or take a tenth) with their coatings, Calico Coating website says their coating is 0.0002 to 0.0004" thick i.e. 0.0004" to 0.0008" reduction.

I have ordered some MS2199HX (0.001" oversize) bearings from Calico, reckon I will get clearances within the range I'm looking for, fingers crossed.

Cheers Simon

chpmnsws6

iTrader: (70)

You would not want to harden your bearing. it is your sacrificial item in your engine. If you were to harden it, you stand a better chance of killing your crank beyond repair if something were to go wrong.