[joes455]

All measurements were done with a Fowler bore gage crank was measured with starlet mic ,I'll be getting it linehoned regardless .The vertical clearance was excessive due to crank being worn by .0005.Should the clearance get bigger or smaller as measuring closer it gets to parting line ?Also when checking saddle bores should they be perfectly round ?

[HWYSTR455]

I used to mock it up with bearings and crank, light film of oil, torque to value, rotate crank a few times, remove the crank, and take measurements w bearings in place.

That will give you the most accurate measurements.

Is the workshop very cold? Temp-wise?



.

[chiphead]

Originally Posted by joes455

All measurements were done with a Fowler bore gage crank was measured with starlet mic ,I'll be getting it linehoned regardless .The vertical clearance was excessive due to crank being worn by .0005.Should the clearance get bigger or smaller as measuring closer it gets to parting line ?Also when checking saddle bores should they be perfectly round ?

It's been my experience that the bores themselves should be fairly round until you get right at the parting line. The parting line taper is in the bearing inserts themselves. The clearance should be tightest 90* to the parting line then get looser by about .0005 as you approach the parting line. This is to prevent the bearing crush causing a high spot at the parting line. The taper can change depending on the bearing crush, the bearing type, torque value, etc etc. Rod bearings can have more parting line taper because of how the rod bearing bore can distort during operation.

[HWYSTR455]

Yes. And that's why I mock it up first, remove crank, torque caps to value, and measure with the bearings in place. (After crush)

That should provide readings as it would be in use. Or as close as possible.

The lock/locating tabs on the bearings is an area that will not 'crush' much, or not as much as the rest of the shell.

Old gearhead machinist suggested I do it this way a long time ago, and continue to do so. Try it both ways and take readings and see what you get. Will make a believer out of most.


.