Bearings - Coated or Not?
 

Trying to make a decision... loaded question coming...

I'm totally confused by the many choices of bearings available. Clevite, King, ACL, etc. Coated, non-coated. H-series, V-series. I have, in the past, used Clevites across the board, but hearing that King's Alecular bearings are really good.

This is for my blown 454 project that I'm looking at spinning to 6K max, 7 lbs or so. I'm set up STD across my mains and rods.

Not looking to start a debate. What should I run?

Thanks!

absolutely use a coated bearing. The Kings are a little more forgiving if you get some trash in the motor. Can't go wrong with Clevite either.

Any concerns with tighter clearances caused by the coating?

Clearance should be the same coated or not.

the use of coated bearings is a personal choice.the vast majority of marine engines do not have coated bearings.i reciently took a 454 marine engine apart that had a ton of hours on it,still had the origional bearings that gm assembled it with and they looked as good as new.

Mike, that's how mine was when I pulled it apart. Pretty much perfect condition.

Why not go with it? I do on every build, but I don't do anything stock or sub 5400 rpm. Tell your machine shop you want to use coated bearings and make sure they have the block, rods, and crank. With precision I discuss the build and clearances I want, they hone the rods and line bore of the block, make sure we have sufficient bearing crush and measure for the clearance to the crank. If it's tight they will open then mains or rods up a little and keep us where we need to be. If that isn't going to work like when using a pos eagle crank .0005 and .001 bearing shells are used. I don't deal with cut cranks at all, .010, .020 etc. just personal preference not to deal with that. Just my opinion. From what I understand merc doesn't use coated bearings on the 1075 stock.

don,t get me wrong,im not saying not to use coated bearings ,just saying that most don,t i see no adverse reason not to use them other than they cost a little more.edit in,i forgot to mention that the coating is applied to the standard bearing shell.the coating is app .00035 thick,that means the clearance will be .0007 less with the coated vs non coated.

I went through the same decision process, and ended up running non coated. I ran Clevites on the rods, set clearances there around .025 - .027. I had some serious issues with a screwed up line hone job that had my main saddles tapering from back to front. Had to find another machine shop to square things up for me. After that was done (and the proper crush was established across the mains), I found that my main clearances were too tight for my liking - on the order of .021 across main #1. I ended up having to buy a set of King bearings in a .001 undersize to give me a little more clearance across the mains. What a PITA it was to get my clearances where they needed to be.

You are measuring your clearances with a set of micrometers, right? Not plastiguage, I hope.

Oh yeah, no one answered your question about P-series and H-series. This is dictated by the fillet radius of your crank. Most of the aftermarket cranks require the H-series bearings, because the fillet radius is larger. Run a P-series on these cranks and you will have problems. The H-series are slightly narrower to compensate for this. Best to call the manufacturer of the crank and see what they recommend. You will probably be able to tell if you use the wrong ones - the crank will not rotate smoothly when the mains are clamped down.

I think the V-series are usually reserved for the max effort builds. H-series will probably be just fine for yours.

Bud man plasti gauge may be be more accurate than your micrometers if you have .025-.027 clearance. ;) I think you meant .0025-.0027

There is some good articles out there on the pros and cons of the different bearing types and what they bring to the table .but oh the punishment even oem bearings can take if the clearances are absolutely positively exactly dead nuts on

My block needed nothing done to the main bearing bores. The crank is the factory forged unit that it was born with.

My machinist said that if it weren't for the piston issues that I had (one with slight erosion, and three that made contact with something in their lifetime), there would have been no reason to ever have messed with the bottom end.

I'll be measuring everything with a micrometer and a dial bore gauge. :)

Coated vs non, I can see the points for either one. I guess it does come down to preference. Mike,thanks for bringing up the clearance change. I thought I had read somewhere that the coating makes a slight change. This confirms it.

tom,coated bearing does change clearance,look at post 8.

Yep, I saw that. Typo on my iPad (digitizer is going south). I'll edit the post. I was trying to thank you for confirming what I'd seen elsewhere. :)

personally,,I don't run them in my engines,,I save the sixty bucks for other parts.you lose oil pressure for some reason,,coated bearing aren't gonna save chit.
yeah,nascar uses them,probably gives them .0001hp advantage,thats why they put all the coatings on,,they're hoping to get every little hp they can.

but hey,coated bearing look cool.

I'm going to go the route of uncoated. I see where they can be useful, but agree that if something gives up the ghost, the bearings will probably be the least of my concerns. If the crank were to be damaged, I'd replace it versus turning it anyway.

Damn! I was wondering why I didn't have any oil pressure, even with 90 wt gear lube! ;)

Quote Originally Posted by Unlimited jd View Post
Bud man plasti gauge may be be more accurate than your micrometers if you have .025-.027 clearance. I think you meant .0025-.0027






Thats clearance for dry sump motors,no oil just a zerk fitting on end of crankshaft.:picard1:

I have ran both, I did have the coated bearings help when I split a cylinder wall and got water mixed with oil, saved crank... so it worked, on my current builds I am using non coated just for the fact I am going broke or I would LOL

As far as Plasti gauge, there was a guy on one of my Mustang boards telling me last night that was more accurate then a mike and bore gauge.... WTF?? he said math can be wrong, plasti gauge don't lie... WOW

my guess is math was not his best subject,lol.

Mike are these what you use ? [ATTACH=CONFIG]536974[/ATTACH] :lolhit: I know I'm starting to need a set .

those are not as thick as mine,lol.

lol I was floored with that guy.... Plasti gauge lol

I thought I was the only Ford guy on this site! Lol. What are you running in your Mustang?

Just be glad he's not your machinist! Sounds like something a carpenter might say...:cartman:

Lol I'm all ford bud, only think that isn't is my cj and boat, I have 94 cobra with a 331 stroker and a novi blower 11lbs boost fun street toy

[ATTACH=CONFIG]537008[/ATTACH]

NICE!!!

I have a 90 352 (302 based) turbo setup. Makes 900hp at 15psi when I ran out of fuel LOL. Hoping to go back and make 1100 with new fuel system and 20-25psi and a few more upgrades. https://www.youtube.com/watch?v=WoQN...ature=youtu.be

Sorry to Hi Jack but I'm running uncoated bearings!!