pre load: How tight ?
Posted: Tue Aug 16, 2011 7:26 pm
I've found two methods of finding the correct amount of crankshaft pre-load described on this forum:
"The generally accepted preload on the cranks is .05-.10mm[.002"-.004"] You should feel some drag but the crank should fall on its own when the heavy part of the flywheel is up" - wdietz186
"To do it right you will want to measure the crank end float with a dial indicator. Measure the end float and then add an extra 0.004"." - Den
Do the amount of pre-load using the two different methods end up as the same ?
Or to say it another way: How tight will the crank be using the "dial indicator method" ?
I have adjusted the end float twice, using the first method, but it ends up loose after a few thousand kms. The first time I used the smaller diameter shims which didn't work well because the base was a little concave, but now it is loose again
I'm afraid to put too much pre-load as this will stress the engine too much I guess ?
Stian
"The generally accepted preload on the cranks is .05-.10mm[.002"-.004"] You should feel some drag but the crank should fall on its own when the heavy part of the flywheel is up" - wdietz186
"To do it right you will want to measure the crank end float with a dial indicator. Measure the end float and then add an extra 0.004"." - Den
Do the amount of pre-load using the two different methods end up as the same ?
Or to say it another way: How tight will the crank be using the "dial indicator method" ?
I have adjusted the end float twice, using the first method, but it ends up loose after a few thousand kms. The first time I used the smaller diameter shims which didn't work well because the base was a little concave, but now it is loose again
I'm afraid to put too much pre-load as this will stress the engine too much I guess ?
Stian