plastigauge measurements

[Figoulu]

Hi all

My question is... when overhauling an engine,it is usual to check the clearances between cranshaft journals and their covers, as well as connecting rods and their covers, to make sure the oil pressure will be fine...

When using plastigauge to measure the clearance, may we understand that we have to :

- torque to nm + angle tightening as it would be for the final assembly before then... undoing everything to check and compare the width of the plastigauge ?
OR
- torque to nm only WITHOUT angle tightening ?

My question is more about the bolt resistance during this checking, as I think, those cannot be reused after this strong torque sequence...

As a consequence... buying new cranckshaft bolts appears very expensive, this is why I was wondering what is the normal way of checking platigauge...

thanks for your advices...

[Figoulu]

No clue anybody ?? 

[DaveB]

Well I don’t know for sure but I don’t think the additional angle beyond the specified torque reduces the bearing clearance, just stretches the bolt slightly for better clamping.
Someone with more experience will help soon!

[ja17]

The connecting rod bolts can be re-used unless they are stretched beyond factory specifications. Normally they are not but should be measured. The specifications for length of the stretch bolts should be in the BBB or the "Technical Data Manual". I also agree that the final angle of rotation should not make a difference in the clearance. 

[Figoulu]

Ok thanks

So as I understood, simple torque spec WITHOUT angle tightening is enough for plastigauge measurement !