So i have problems with my new engine wearing out bearings quite fast . First let me tell you about my old 455 that is rock solid.
It’s a later block , Fa, with a later crankshaft small cn, I don’t know what the clearance is on the rod or mains, but whatever they are it works. It has a hv oil pump, I don’t know what spring, but it is not shimmed, and has a 5 qt pan. The block has cam bearing restrictors with regular cam bearings, the cam is a JM 25 28 hydualic flat tappet. It has Joe Mondello restricted pushrods, Scorpion rockers. The heads are iron E heads with Ferra valves and no drainback mods. Torker intake with Holley 950. I’Ve had this engine about four years and spanked it regularly, runs flawless. I shift it at 6500 ish all the time, thats right around where it stops pulling. Oil pressure is always 60 psi at high rpm. Also Clevite full groove mains.
The new 455 is built more for racing. Older F block with no cam bearing restrictors. Crank is a bigN one. That one is ground for large clearances, 4 thou. It has had Speed pro half grooved bearings and Clevite full groove bearings. Also a high volume oil pump with shimmed green spring, and a eight qt pan with correct 2” drop pickup. I have Eagle rod’s with Icon flat top pistons. The cam is a Cam Motion solid roller with 609/254-586/258 on 108 LSA. Crower 66294h lifters and no lifter bore restrictors. 3/8 unrestricted pushrods. To top it off i have a Edelbrock heads with 57cc chambers, so it comes out to 12/5:1. Also a Torker and same 950. Also Jesel shaft rockers.
This engine gets about 15 minutes out of a set of rod bearings. I have never even really opened it up yet. The first time i had it together i was at a stoplight idleing in gear and watched the oil pressure drop off slowly and would not move when the engine was revved. Got it apart and it had shredded the rod bearings,mains not too bad. So I thought it was too tight, 3 on mains,2.5 on rods. Got the crank ground for 4 thou everywhere. Ran it for about 15 minutes at low rpm around 3000, got home cut the filter with snips, lots of copper and silver. It had great oil pressure and no mechanical noise. Got it apart and it was the rod bearings again. The machinist checked the rods before and so did i, they were good,the crank measures right on everywhere.
So i guess i almost have a magazine test article going on here. To restrict or not to restrict, that is the question.

It is externally balanced. .014 side clearance. BHJ external balance dampner and a ATI external balance flexplate.

But this rotating assembly was balanced?

Yes,the assembly was balanced.

It wipes out all of them or just a few?

The bearings on the front rod journal look the best,not even into the tin. Six and seven are the worst.

If the oil holes are clear then you have a balance problem. How does #4 main look?

Rods seven and eight are at the machine shop,wanted to get them checked out

Any chance the rod is bent? Seems the wear is concentrated on one side of the bearing.

You need to find another machinist, he sucks.
Just because things are in size doesn’t mean They’re IN-LINE.
I see clear misalignment issues and most likely a poor relationship between the angle of the rods/pistons vs the cylinders, they’re most likely not perpendicular. I believe your crank pins aren’t parallel either.
You need to find a better machinist.

Is there a way I could check to see if the bore’s are square to the crankshaft centerline?

Huh? That won’t prove what he’s looking for.
The only real way is to mount the block in a boring bar, then run a dual indicator down the bores.
I’d start from scratch and have it align hone first, then measure the square from there.

The block was line honed as part of the initial build. I found a different machine shop in town that has a cnc machine that registers on the main line and is able to probe the bore’s to see if everything is in order. Definitely going to have it checked out before going any further

Yeah definitely hard to diagnose via the Internet. The pistons all look good, no wierd wear or anything like that. All the rods were installed with the chamfer facing the journal cheek. The crank is fine. If the block had cocked bore’s the wear pattern on the bearings would be opposite of each other not concentrated on one side like i have. The thrust is really sealing the deal for lack of lube. I run the same turbo400 and cooler setup with the other engine and never had a problem. This crank’s thrust surface is fine, no sunburst pattern, and very smooth. The only thing that could be causing it to wear as quickly as it does,is lack of oil. It’s going back together pretty soon, ill let you guys know how it turns out. Thank you all for your feedback.

You Tube

The oil pressure was good even with the big clearances, 70 cold 45 hot at about 2500 rpm and 25 idleing. I have the max perf olds book, read it cover to cover. It has alot of good info, thats why i had the crank ground for loose clearances the second time around. I’m aware of the oil pump interference with the main cap hardware. My pump is clearenced for it and sits flat on the cap. I have the block tapped for restrictors on the cam bearings and lifter bores . Been doing alot of reading about engines originally designed for hydraulic lifters and trunnion or skid ball rockers, and when the oems put solid lifters in those engines back in the muscle car days. They made the lifters very restrictive, because the block itself flows way more oil than needed. I don’t have one stock component in my valve train, so why leave it stock especially if im wasting bearings at half hour intervals. The crank is getting polished, it’ll be ready tomorrow,just have to clean the block. I’ll let you know how it goes. Thank’s again

Well looks like restrictors worked for me, just got it back together last night. Thats the filter on the second oil change. Drove it around a bunch today, oil pressure is 60 cruising, 30 idleing in gear. Runs perfect no valvetrain noise. Wish i would have done it to begin with.