Scraping white metal bearings

[Stuart Giles]

A good way of seeing what's really going on with big end clearance is to use stuff called Plastigauge. With a 2 bearing motor you really want a bit more clearance at the outer edges of the bearing than at the centre. Plastigauge comes in round strands, bolt up the bearing with a strip in there and then you can use the supplied card to tell exactly how much clearance you have.



This pic is from a V8 that I've just built for a mate, can't find one of doing an A7 motor at the mo' but the stuff obviously works the same way.