After lunching my old engine on track, I thought I would start off as I mean to go on with the new one and put new big-end bearings in with ARP bolts.
I also inspected the main bearings. Everything is near-perfect, apart from main bearing #1.
Is this a big enough problem to warrant taking the crank out to replace the main bearings and polish the crank, or does this count as normal/healthy
wear and tear?
Engine is an M3 evo btw.
Those aren't marks at the top right of the main journal, they're bubbles in the oil. The only issue is the discoloured stripe.
A tiny bit scored.
Have the crank journals checked for size.
If they are OK, have the journals polished, and put in a new set of shells.
My bearings were far worse than yours and the crank was still OK.
Rover V8
My camshaft and follerw were pooped too!
cost me £2k to rebuild the V8, but was worth it long term.
Slightly Worn Bearings
looks pretty normal to me. Any marks on the crank you can catch with a fingernail? old fashioned way of checking, but must still be valid.
It is often possible to replace the mains without taking the crank out, though can require a little faffing.
quote:
Originally posted by cliftyhanger
looks pretty normal to me. Any marks on the crank you can catch with a fingernail? old fashioned way of checking, but must still be valid.
It is often possible to replace the mains without taking the crank out, though can require a little faffing.
how much is a new set of shells? you've taken it all apart to have a look, is it worth the investment and piece of mind if new shells can be had at a reasonable cost?
Oh yes, deffo new shells unless the old ones are very good, which they are not (but still look normal)
It's not the cost of shells that's the problem, it's more the hassle of taking it apart enough to remove the crank (this is a main bearing). Not that I'm against it as such, but no point doing it if it looks OK. I'll definitely do the big-ends (even though they look great).
I was debating this with my motor (mine looked much the same only it's a pinto!) but came to the conclusion that it was better to get on with it now and thus reducing the possibility if me needing to remove the motor at a later date. The crank is at the engineers now being checked for roundness and will be polished/ground depending on what they think, while its there it's a good excuse to lighten and balance with the flywheel!
Those look fine to me. Box it up and enjoy the summer! There are a couple of wear-marks but that could happen with the first revolution of the crank in a new set of shells so I would say they're fine. It also looks like you can still see the grind pattern on the journal, so no problems. All IMHO, and if it was mine or an engine I was building, I wouldn't be concerned at all.
They look a lot better than these 
These came from a Zetec that i stripped for somebody
Daft as it sounds the oil pressure was fine it was just knocking its tits off
