Bearing inspection

[SuperRedMR2]

Got my crank out the other night.

All main ends are fine.

7 out of 8 rod bearings are fine except this one. Any ideas?
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[PW@Woodsport]

If i was give it my best guess, you've mismatched a cap to the correct rod, which are meant to be in pairs.... if there is no wear on the other half of the shell bearing then the only explanation is you've put the wrong cap on that rod.

They are numbered and matched for each conrod/cap and cannot be interchanged. That wear is the diference between the cap and the rod.

Or you've installed the cap the wrong way around.

[SuperRedMR2]

Hi Paul,

Unfortunately the rods I pulled from the engine were already mismatched. I put them back together the first time around the way I found them.

[PW@Woodsport]

Then you have your answer

[SuperRedMR2]

No Paul what I'm saying is the engine I was supplied came with mismatched rod caps. So I put it back together the way it came apart.

[PW@Woodsport]

Yes i know, and i'm saying now you know why the bearing shell is wearing like that..... mismatched caps.

[SuperRedMR2]

I can't do anything about that now as the head isn't coming off and I don't have a Conrod with correct cap to replace it with.

Funny though that it's not the only mismatched cap in that engine and the rest of the bearings are ok.

[PW@Woodsport]

The others either have the correct number 1,2,3 so just happen to be right, or very close.... there is only a couple of thou between each number, on the one that is worn it's probably at the opposite end.

Either that or an installation error and let's be honest mate, there's been a few.

All part of the learning process

[SuperRedMR2]

Paul the engine you supplied me with came with 3 off no.2 rod caps and 1-off no.1

Number 1 cap was on the correct piston but the rest I couldn't do much with...

Number 2 was on number 2 piston and this is the one with wear and the others okay.

Yes there have errors but my mathematical skills from 1-4 are okay if I had the correct bits to begin with.

[PW@Woodsport]

LOL you're saying that like it's my fault?

I supplied you with an engine that someone else built, not me, so they obviously got the caps in the wrong order, so why say it like it's my fault when i obviously had no idea the caps were wrong?

Secondly if you knew they were wrong the first time around why did you proceed? I mean surely you should have corrected the issue you spotted then?

I don't appreciate being blamed for someone elses mistake, mate.

I'm out, was only trying to help you.

[SuperRedMR2]

I'm not blaming you I'm merely explaining that the caps are wrong and its it not down to installation.

I know I've made mistakes and openly admitted on here but don't appreciate being reminded and it sounds like it's amusing to you.

[PW@Woodsport]

What the hell are you on about mate? Amusing to me? How do you work that out?

Where have i even hinted it's amusing that you're having so many issues? I've been trying to help you!

Once again, if you saw the caps were wrong the first time you had it apart then why didn't you fix that instead of putting it together with the wrong size caps on?

You already knew the caps were wrong before asking why the bearing was worn like that...... so yes it IS down to installation.

I don't understand any of that or why you're having a pop at me.

Good luck, but i'm not here for that

[SuperRedMR2]

I couldn't really do anything about it at the time, as I would have had to bought new conrods together with caps. But assumed as the bearings were okay at the time, no further issue was going to take place.

I'll get some engineers blue or some plastigauge on the bearing cap to see if my tolerances are out.

Let's just leave it now.

[PW@Woodsport]

That won't work, it's one half of your cap/conrod that is the wrong size, so plastigauge will only show you the overall clearance from both sides.

If the original bearings did not have wear on them like they do now then you have either mixed the caps up, installed them back to front, or have the wrong size shells for that cap....if it was ok before dismantling then you've done something wrong.

For the record i don't find anyones mistakes amusing, i'm only trying to help you, and it appears you've taken my observations the wrong way.... still i'm the only one bothering to try and help you.

[SuperRedMR2]

I thought the whole of the bearing would have been worn not just one end?

[LimeyMk1]

I have a good few complete 4AGE conrods in the loft, how many would you like?

[SuperRedMR2]

Hi mate,

My head isn't coming off again I'm afraid.

But thank you for the offer.

[SuperRedMR2]

This is the other side of the worn bearing

[LimeyMk1]

Paul the engine you supplied me with came with 3 off no.2 rod caps and 1-off no.1

Number 1 cap was on the correct piston but the rest I couldn't do much with...

Number 2 was on number 2 piston and this is the one with wear and the others okay.

Yes there have errors but my mathematical skills from 1-4 are okay if I had the correct bits to begin with.

From what I recall the numbers aren't anything to do with the position in the engine (cylinder 1,2,3,4) but the size of the bearing that they take.

There is an M stamped across the join line between the cap and the conrod. This is what you look for to make sure the cap is on the right way round and matching the conrod. I can't remember if there is a corresponding cap & conrod size number but I don't think that the caps were ever meant to be replaced, just the whole conrod.

Bearing replacement etc is pretty thoroughly covered in the BGB.

[SuperRedMR2]

Paul the engine you supplied me with came with 3 off no.2 rod caps and 1-off no.1

Number 1 cap was on the correct piston but the rest I couldn't do much with...

Number 2 was on number 2 piston and this is the one with wear and the others okay.

Yes there have errors but my mathematical skills from 1-4 are okay if I had the correct bits to begin with.

From what I recall the numbers aren't anything to do with the position in the engine (cylinder 1,2,3,4) but the size of the bearing that they take.

There is an M stamped across the join line between the cap and the conrod. This is what you look for to make sure the cap is on the right way round and matching the conrod. I can't remember if there is a corresponding cap & conrod size number but I don't think that the caps were ever meant to be replaced, just the whole conrod.

Bearing replacement etc is pretty thoroughly covered in the BGB.

Thanks mate, i'll look at my rods later.