14-06-2021, 07:24 PM
Hi Jon
I'm not completely clear what you're measuring. I assume the run out of the flywheel, but are you doing this before or after fitting the crankshaft in the crankcase?
Either gauge (1" or 1/4") will measure to .001" and I don't think you need less than that. The total range you're measuring may well not exceed .020", and hopefully a lot less than that. Woodrow reckons run out should be less than .004" between extremes (i.e. total movement, not just deviation from the mid line) and if measured with the crank in situ you should address anything over .015", which seems a lot to me.
Personally, I don't begrudge spending on precision measuring devices, but in this case I'd buy a cheapie new 1" dti and put some thought into how to mount the crank and flywheel for measuring run out, and spend more on buying a decent stand for the dti. Cheap ones are a pain.
Another use for your new gauge could be to establish TDC by bracketing the piston travel, as has been discussed on here recently.
I'm not completely clear what you're measuring. I assume the run out of the flywheel, but are you doing this before or after fitting the crankshaft in the crankcase?
Either gauge (1" or 1/4") will measure to .001" and I don't think you need less than that. The total range you're measuring may well not exceed .020", and hopefully a lot less than that. Woodrow reckons run out should be less than .004" between extremes (i.e. total movement, not just deviation from the mid line) and if measured with the crank in situ you should address anything over .015", which seems a lot to me.
Personally, I don't begrudge spending on precision measuring devices, but in this case I'd buy a cheapie new 1" dti and put some thought into how to mount the crank and flywheel for measuring run out, and spend more on buying a decent stand for the dti. Cheap ones are a pain.
Another use for your new gauge could be to establish TDC by bracketing the piston travel, as has been discussed on here recently.