Argh bearing clearances


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Yazza54

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Feb 19, 2016
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Right I got home tonight and thought I'd start doing the plastigauge sanity check

Started with the rods and didn't get very far...

The bearings are ACL race (std size) which from what I gathered were supposed to be fairly loose if anything

The plastigauge I'm using is the green type which as far as I'm aware is spot on

I took my first rod and installed it onto the correct journal (no.4) First torqued the bolts to 15ft lb then 33 ft lb in careful increments. Got these torque specs off the net hope they're right??

When removed the plastigauge is so crushed it's basically fallen apart in the middle and the footprint of it is massive. I tried this rod and bearings on the opposite journal, same again. Like the bearings are massively tight. What the hell is going on, am I doing something wrong?

I am doing it with the crank out of the block for the rods but can't see why it would matter...?

 
Is the rod/crank moving? Looks like it from the plastigauge.

What's the clearance spec on the plastigauge? You get different colours for different clearance
 
0.007 - 0.020" plastigauge green

I better drop it in the block so there's less chance of it moving but I've a feeling it's gone in the middle because it's crushed down so much. I did it 3 times and same outcome
 
As above looks like its moved. Also is that not red gauge? I use ACL flexigauge green is the size you need and red is for tighter clearances.
 
Well I ordered green and the packaging said green... I assumed the actual stuff was all the same colour but supplied in different thicknesses? I could measure the strips with a micrometer if I knew what thickness they should be
 
It's gone in the middle as that's where the most compression on the plastigauge is as your crushing it.
Some people have all sorts of issues with the acl bearing clearances.
 
Hmmm I will try it on the mains and see if I have similar problems, if they come in spec I'll know it's the right plastigauge. TBH the rod bearings I took out were nice anyway... Just wanted to renew everything. GRR
 
The stuff I use is color coded mate the packet and the gauge. But like I said the red stuff is for tighter clearances than green so if it was a problem with the clearance I would expect to see the opposite of what you have got there. I think it's down to the rod moving. I would do it with the block on a stand and start with the mains. Check clearances and if they all come inside spec, put assembly paste/graphogen on the bearings torque crank into block and make sure it turns freely. Then do ring clearances and assemble pistons then onto big end clearances.
 
If you've got the right micrometer you could measure the old and new bearings. Obviously need a mic with a curve on it
 
Just done all the mains, I'm convinced they sent the wrong plastigauge!! They are all miles out according to this, very tight it would appear, not even on the spectrum of clearance that the green plastigauge should measure.

What is making me think it's the wrong plastigauge is that whilst I'm not getting the outcome I wanted they're all pretty consistent across the journals. What do you guys think??? Pissed off!!










 
I haven't torqued it down again without the plastigauge.

Just done it once to gauge it and posted the results but I see where you're coming from

I know the ACL are one size fits all but if this is the right plastigauge it would mean that they are seriously tight and I just can't see it
 
As rob says, lube them up and torque it down. If it moves freely chances are it's not that tight.
I did have some plastigauge spare but I'm not sure what I did with it.
I'll check out the garage tomorrow and if I find some I'll send it to you so you can clarify yours is wrong
 
Try it mate take you 5 minutes and if its tight it wont turn. Don't try and force it... if it's in spec with lube it should turn freely with literally zero effort. I love it when you've measured it up and its all torqued down just to give it a wee spin before the rods go on. But i'm weird like that lol.
 
Since they all came out the same when I gauged them earlier I just put no.1 and no.5 main caps on and lubed bearings. Dead free, no tight spots. Feels lovely.
 
haha it's class love that lol. So providng it was the wrong gauge scale was wrong and they are all close together and in spec then you should be good at that then just rods to go.
 
the rods I checked were pretty
Much the same too.

Hmmm building a motor by feel... Maybe not as crazy as it sounds

Id like to sanity check some but I find it hard to believe they would all be miles out and it honestly feels really good
 
I know I know

Have emailed the seller hopefully they will send me another set
 
Right must confess - my cock up this!

So the Plastigauge (UK company) and Plastigage (US company, notice no U) are different colours/thicknesses

I was told to get green so blindly bought green from the UK company, which is too thick. I have ordered Plastigauge red which is the correct size.....

Hopefully this will stop anyone else making the same mistake!!
 
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