Plastigauge main bearing clearance?

#1
New bearings for the main caps with crank in block (heads still on block)

Gonna try and sneak the uppers into place and need to use some oil so they slide in...

If I use plastigauge on the cap side of the bearing (installed dry) just figure my plastigauge on showing half the clearance because the upper bearing will already have the oil film in there?

Any thoughts appreciated
 

earlbrown

runs with scissors
#3
One of these days I'm going to use my bore gauge to see just how inaccurate plastigauge is.


Slix, what's going to be your procedure to know for 100% certain you don't put a small piece of crud up into the main saddle in the block (or even worse, into the oil feed hole)?
 
#4
One of these days I'm going to use my bore gauge to see just how inaccurate plastigauge is.


Slix, what's going to be your procedure to know for 100% certain you don't put a small piece of crud up into the main saddle in the block (or even worse, into the oil feed hole)?
I was hoping to find something the shape of a mushroom and the stem would fit inside of the oil hole and into the actual bearing that would just be enough to hold the bearing so it sounds out when I rotate the crank..

I was thinking if I could do that then the bearing would actually wipe away anything that was in the saddle and when I put the new bearing in it should already have a clean surface...

Haven't really had any luck finding the mushroom pin thou

Plan B which is roll new bearing in after I push the old one out and then maybe put something through the oil hole like a Q-tip..

Wish there was some way I could pressurize the oil system and then just blow air through it and it should push anything out through that hole?

Guess that's something I think about thanks.. any thoughts appreciate it
 

bison

Moderator
Staff member
#5
It depends on the reason why you are changing the inserts. Plastigage is certainly better than using nothing. If you knew the bearing clearances you previously had a bearing mic would be more accurate in determining the oil clearance


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