guys, as a guide, I'm no IAME expert, but I am a chartered engineer who does a ton of work with high speed radial ball bearings up to speeds of 70,000rpm with all the big high quality bearing manufacturers...... any radial ball bearing has end float 10 times the radial clearance.....it alarms some people but all bearing manufacturers work this way, if they are NSK bearings they will have a rating of say C3, C4, C5, C6 and so on.....just had a google around and I can see the IAME uses a C4 bearing, which according to NSK charts is an internal clearance of 0.008mm to 0.013mm....so x10 the worst figure this is 0.13mm.....8 thou is 0.203mm......which I would consider the absolute maximum......so to conclude, if you have end float of 1mm, your bearings are utterly shagged and need replacing, at 1mm I think you will be running a high risk of bending a con-rod or wrecking the piston & bore.
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