Cylinder bore specs for an engine rebuild
Hi forum. I embarked on the improbable quest of rebuilding an ACL engine (improbable because I have never done anything like this).
The specific question of the day has to do with cylinder bore measurement. I have to measure them with a dial gauge to decide whether they need to be rebored or not.
I got two manuals, one from Volvo and one from VW, and they give different tolerance levels. Both say I should measure perpendicularly and longitudinally at three different levels of depth.
Volvo says a rebore is necessary if "any two points are more than 0.04mm from each other", while VW states "if any one point is > 0.1mm away from original spec".
I measured nothing more than 0.1mm from spec, but I do have cases of 0.06mm difference between two points in the same cylinder.
Which one is right? Or is a rebore a good idea anyway given the engine has already 270k km on the clock?
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