TomZ

iTrader: (2)

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!

Black Baja

iTrader: (2)

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.

TomZ

iTrader: (2)

Any concerns with tighter clearances caused by the coating?

Black Baja

iTrader: (2)

Clearance should be the same coated or not.

mike tkach

iTrader: (3)

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.

TomZ

iTrader: (2)

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

Unlimited jd

iTrader: (5)

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.

mike tkach

iTrader: (3)

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.

Budman II

iTrader: (1)

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.

Unlimited jd

iTrader: (5)

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