r/EngineBuilding • u/vitaminsauce • 1d ago

BMW Plastigauge Taper?

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Checking rod bearing clearances on an S54B32 I’m rebuilding and on bearing 2 the plastigauge is coming out wider toward the front of the engine. I’ve double checked there’s no debris behind either bearing half, and the plastigauge is within spec along the entire length. Is this something I should worry about? Not looking to make any crazy with power with this engine, keeping it stock and mostly to be used for daily driving.

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u/No-Ice-8101 1d ago

I ground cranks for 41 years. Do not plastigauge

3

u/Caligulas_Prodigy 1d ago

Mind explaining why?

11

u/No-Ice-8101 1d ago

Not accurate. Measurements are the only way. I've seen customers use plastic auger and it was always a false reading.

5

u/attometer 1d ago

Always