[slowbird]

Curious if .001 under 3" main bearings were ever made and if they were anyone know where a set can be had?

[PAUL K]

Years ago they used to be available but not in a performance bearing like the Sealed Power 113M.

Can you get by with a coated bearing?

[cgeise]

don't think so use a heavier oil )) or have half a thou taken off main caps.

[S/st 54]

Not a performance bearing but......



http://www.summitracing.com/parts/slp-4040m1/overview/

[PONTIAC DUDE]

I have used them and are a different material 3/4 groove perf brg.

[PAUL K]

I'm glad to see they are making these bearings again... thanks for posting the link.

[Dragncar]

Those tri metal main bearings with the round hole you need to drill a hole in the bearing to match the one of 3 holes that intersect. The hole on the "tab" side of the bearing is the one that gets the shot of oil. If you do not do this the oil shot hits the back of the main bearing, moves over to get to where it needs to go.
Think about it, there is not much time with the crank spinning around for everything to line up for a straight shot. You do not have one unless you drill the hole. Rod bearing problems will be had if you do not drill it.
Wrap the bearing in a rag(or use soft vise jaws) and carefully drill your small pilot hole then the hole to match the size of the hole in your block(drill from the back side of the bearing). Take a jewelers file and radius the edges on the crank side of the bearing.
I have had great luck with this. Never had a bearing issue. 1200+ runs on engine. Still has 55lbs hot.

[67GTO4SPEED]

[/COLOR]

Originally Posted by Dragncar

Those tri metal main bearings with the round hole you need to drill a hole in the bearing to match the one of 3 holes that intersect. The hole on the "tab" side of the bearing is the one that gets the shot of oil. If you do not do this the oil shot hits the back of the main bearing, moves over to get to where it needs to go.
Think about it, there is not much time with the crank spinning around for everything to line up for a straight shot. You do not have one unless you drill the hole. Rod bearing problems will be had if you do not drill it.
Wrap the bearing in a rag(or use soft vise jaws) and carefully drill your small pilot hole then the hole to match the size of the hole in your block(drill from the back side of the bearing). Take a jewelers file and radius the edges on the crank side of the bearing.
I have had great luck with this. Never had a bearing issue. 1200+ runs on engine. Still has 55lbs hot.

Good stuff!

[slowbird]

Thanks to Jason H and Mark Luhn for the quick help.

[steve25]

The factory had them in the Moraine 400 series of bearings that all the tri power or 4 bbl motors came fitted with.

[PONTIAC DUDE]

Originally Posted by Dragncar

Those tri metal main bearings with the round hole you need to drill a hole in the bearing to match the one of 3 holes that intersect. The hole on the "tab" side of the bearing is the one that gets the shot of oil. If you do not do this the oil shot hits the back of the main bearing, moves over to get to where it needs to go.
Think about it, there is not much time with the crank spinning around for everything to line up for a straight shot. You do not have one unless you drill the hole. Rod bearing problems will be had if you do not drill it.
Wrap the bearing in a rag(or use soft vise jaws) and carefully drill your small pilot hole then the hole to match the size of the hole in your block(drill from the back side of the bearing). Take a jewelers file and radius the edges on the crank side of the bearing.
I have had great luck with this. Never had a bearing issue. 1200+ runs on engine. Still has 55lbs hot.

I posted that trick 15 years ago and did that till FM started it with the 3" mains but still do it on the 3.25" mains. Just elongate it toward the feed side of the mains. Never needed to do the rear wider brg.
On the front one, sometimes you have to elongate the front feed hole in the block to get the feed lined up with the groove/feed in the brgs. I also 30 degree the thrust side brg to allow oil to excape from the main and helps from wiping out the back side of the thrust brg. Not needed as much with full chamfered thrust, but where the chamfer is not all the way down the side It needs to be done.

[Dragncar]

P Dude, I learned the mod from Dan Whitmore and your thrust trick from your old website. I do both on my stuff !

[Dragncar]

To further the point of doing this mod, my buddy just blew his 400 to bits.
It was a basic bracket race 400 like my 455. He has a 2nd gen bird, heavy. Ran TRWs like I do with your plain jane china forged rods for press fit. It ran good, with a RAIV cam he was low 11s and dropped to 10.90s with a small roller. Home ported 62s, Victor and a 750DP.
He has had 3 engines in the time I have had my 455 and it is still running great. When he blew it up I went over to talk to him and started asking questions. He is a good mechanic and does all his work like me. He had a rod bearing issue awhile back and got to it before if became a problem. Resized the rod and put new bearings in. First race it let go, I seen a ruined cam and chunked parts below it.
But, he just installed round hole Clevites and did not restrict the lifters. Its worth every bit of effort to do these mods. Could not believe he ran it as is. I gave him a set of my old bearings so he could copy them.
My engine owes me nothing. It could go next pass. It runs as good as it ever has and there are reasons for this. Do these mods, blue print your pump, don't over rev it (iron heads just go slower anyway) and cut your oil filter open every change and inspect.
Its all about attention to detail.
It sure would be nice if bearing companies made .001-.002 undersized rod and main bearings like they do for chevys.