Big end play.

[Call the midlife!]

I'm asking this here for the benefit of all rather than privately ask my usual "go to guys" but bear with me because I'm struggling without Tapatalk so haven't been engaging on the forum much since the updates.
As some of you know I thought I'd spun a bearing last week due to oil starvation and hearing a knock.
On initial inspection of the big end shells I couldn't see anything amiss, none were out of place and no sign of white metal.
We've since decided the knock was probably the timing chain slapping, backed up by the fact it's smashed a piece of the outer casing from the oil pump.
So... The trained monkey came round tonight and we torqued the bearing caps up and he gave them a coat of looking at and if you wiggle them strongly there's fractional movement.
"They're shagged aren't they?" "I think so Dad".
So out with the plastigauge and here's where the question lies, all 4 were 0.035-0.038 which if we're reading the specs right puts them still in spec.
So can they be in spec with the chart but still have that fractional movement?
For clarity I'm reading the connecting rod oil clearance measurements on the spec sheet as it doesn't say "big end bearing" anywhere...

[Carolyn]

I take it the shells were completely dry, front and back, when you plastiguaged them?  They need to be.

So you measured a clearance, which won't be there when there's oil present.  A small clearance equals a small movement.

Connecting rod oil clearances are what you're after!!

The clearances you measured seem very consistent and in the middle of the tolerance range and they appear unmarked and undamaged.

You're good!

[Call the midlife!]

I take it the shells were completely dry, front and back, when you plastiguaged them?  They need to be.

So you measured a clearance, which won't be there when there's oil present.  A small clearance equals a small movement.

Connecting rod oil clearances are what you're after!!

The clearances you measured seem very consistent and in the middle of the tolerance range and they appear unmarked and undamaged.

You're good!

Hmmm... Probably not completely dry top and bottom, I know what I'm doing again this evening 😂

Thanks for that though, I knew I'd used those specs the first time around but too much second guessing last night.

[Carolyn]

I take it the shells were completely dry, front and back, when you plastiguaged them?  They need to be.

So you measured a clearance, which won't be there when there's oil present.  A small clearance equals a small movement.

Connecting rod oil clearances are what you're after!!

The clearances you measured seem very consistent and in the middle of the tolerance range and they appear unmarked and undamaged.

You're good!

Hmmm... Probably not completely dry top and bottom, I know what I'm doing again this evening 😂

Thanks for that though, I knew I'd used those specs the first time around but too much second guessing last night.

To be clear, (we used different terms), there must be no oil.  On the surface of either shell, or between the shell and the rod or cap.

[Call the midlife!]

I take it the shells were completely dry, front and back, when you plastiguaged them?  They need to be.

So you measured a clearance, which won't be there when there's oil present.  A small clearance equals a small movement.

Connecting rod oil clearances are what you're after!!

The clearances you measured seem very consistent and in the middle of the tolerance range and they appear unmarked and undamaged.

You're good!

Hmmm... Probably not completely dry top and bottom, I know what I'm doing again this evening 😂

Thanks for that though, I knew I'd used those specs the first time around but too much second guessing last night.

To be clear, (we used different terms), there must be no oil.  On the surface of either shell, or between the shell and the rod or cap.

No, don't worry, I fully understand what you were saying and I'll repeat it this evening with everything clean and dry.

Thanks.

[Call the midlife!]

Well I'm immensely glad I wasn't doing any of that laid on my back under the bugger but no real difference in last nights measurements doing them dry so I'll call that a win!
Couple of the thrust clearances are at the upper end of the spec so possibly that exaggerated the movement when we were wiggling them before.
And to be honest neither of us have had any experience with a partly worn bearing, only properly mullered ones. 
Even at college he's only experienced the mock up ones they have to demonstrate bad bearings, similarly in employment they only come through the workshops when they're fatally fluffed!
So good experience and practice all round really.

[ptennisnet]

Thank you for posting here rather than going to your go to people.  Posts like this increase my theoretical knowledge which gives me confidence to try bigger and bigger jobs

[Call the midlife!]

Thank you for posting here rather than going to your go to people.  Posts like this increase my theoretical knowledge which gives me confidence to try bigger and bigger jobs

It was a matter of logistics at the time, I was struggling with getting to grips with the new forum software and my "go to" people at the time are all on here anyway so it'll always appear on here sooner or later.👍🏻