Picture: main and big end bearings opinion?

[Chimp871]

Before putting the sump back on I removed the main bearing (2nd from front) and big end bearing, both bottom halves.

For almost 60k miles I don't see any copper coming through, there is a score mark on the big end bearing which just grabs a fingernail.

But I could do with an opinion.....

[TVR Beaver]

if they have 60k on them, they are the best I've ever seen....
Have you done the 60K yourself?... how do you know they have not been replaced.... Take the next one off, see if its the same.
Is your engine internaly balanced?...

[Chimp871]

I've not done them all. Its had 5 owners but receipts suggest no engine rebuild or crank balancing (were they balanced?)

I was putting a new sump in and took the chance to check 1 maim and 1 big end bearing. Sadly the sump is back on with the loctite gasket.

If they'd shown copper then I'd have stripped further as I'm working towards a turbo add-on.

Thanks for your opinion.

[Jhonno]

Is the crank marked?

The bearings look VERY clean for 60k.. I take it you are refreshing though?

[N7GTX]

Was there a corresponding score mark on the big end journal?
Mine were shot at just 49,000 miles despite a full history folder and service record Probably caused by oil starvation, perhaps on a track day, who knows.

[TVR Beaver]

Mmm.. you've put them back in?.. not good practice... once removed they should be replaced or they can spin.
Would have been interesting to see the next ones...
Yes, they are balanced... but externaly... so everything is bolted up and the whole thing balanced... horrable way of doing it and can lead to some very nasty harmonics...
You can find a main looking very nice, but the next one totaly shot due to this.
But, if you have no noise and good oil pressure, you may be okay

[Chimp871]

No obvious score mark on journal.

I checked here if it was ok to check a bearing wirh the sump off and put back, opinion suggested ok to continue.

The top bearings weren't disturbed. I would have changed them all but the rear bearing difficult to change without disturbing the rear crank seal. Hence this quick look. If there's a way to change rear bearing without disturbing rear seal then let me know.

Edited by Chimp871 on Sunday 24th September 23:43

Edited by Chimp871 on Monday 25th September 00:14

[TVR Beaver]

In the early days of ownership, I let a well know V8 specialist do mine due to time basicaly and the fact that he said he could do the rear ones as well (no idea how without disturbing the seal).. I was also told the cam was done and got talked into other unwanted upgrades!... It lasted about 2000 miles before It had to come in bits so I did it myself this time... And obviously they had not done the rear set
But he did show me a number of spun bearings whilst I was there. Got to say, I did have a look myself before taking it to them, and it lasted to 500 miles or so before they butchered it

[Chimp871]

I understand that the bearings that came out should have stayed out as I imagine they crush into cap.

So is it okay to replace just the 2 bottoms I took out, the bottom & mathcing top halves or the whole lot.

I'd love to do whole lot except for that rear crank seal and being disturbed.

[QBee]

N7GTX said:

Was there a corresponding score mark on the big end journal?
Mine were shot at just 49,000 miles despite a full history folder and service record Probably caused by oil starvation, perhaps on a track day, who knows.

Baffled sumps are not expensive (compared to rebuilds) and can come with a larger oil capacity, which then takes 9.5 litres of oil.

Look on Mulberry Fabrication's site

clicky here

[carsy]

Chimp871 said:

I understand that the bearings that came out should have stayed out as I imagine they crush into cap.

So is it okay to replace just the 2 bottoms I took out, the bottom & mathcing top halves or the whole lot.

I'd love to do whole lot except for that rear crank seal and being disturbed.

I recon your shells you've put back will be fine.
I've done this on a couple of engines and they've been fine.

[Sardonicus]

Bearings dont spin because they have been removed and refitted so long as they are fitted back to their original placement & clean all is good

Edited by Sardonicus on Monday 25th September 10:27

[Boosted LS1]

Those are good shells and clearances seem to be spot on. I'd reuse them seeing as they're working so well.

[TVR Beaver]

yes.. should be okay, as you say, the tops are crushed into place as you've not moved them.. If you were to replace, you must do top and bottom.

[Chimp871]

Appreciate it gents.

It was a baffled sump I put on from SiFab.

[TVR Beaver]

BTW.. I'm sure you will not find any marks on the crank.. those marks on the shell are typical of use... Its not lacking oil or had a drop in pressure... They are just how they go....
On the ones I had fitted, then removed 2K later... they showed more wear than you show in either of your pics....

[Chimp871]

Its good the bearings show like that BUT clearly not normal for 60k miles. Fyi - The previous owner was on Mobil1, I'm on HPR15 Penrite.

It doesn't seem to make much sense unless the photo has weird light. You would have to think someone did change them but none of the previous owners seemed that way inclined and no receipts to suggest the work took place.

Edited by Chimp871 on Monday 25th September 16:32

Free more pics for balance.

Edited by Chimp871 on Monday 25th September 17:06