Tool Question ..Engine rebuilders
 

Two questions regarding tools... Are the low budget micrometers available from Harbour Frieght accurate enough for measuring critical parts such as crank surfaces? How can you verify the accuracy of any micrometer? Do most rebuilders use plastigauge to determine wear , or do they mike all the parts , or do they just assume the worst and grind the crank by default?
Also , with regards to tourque wrenches...where/how do small shops calibrate their wrenches? I know our mechanics are required by law to constantly recal their tools to insure correct tightness on our aircraft. Any comments from the pros inthis group?

There is more to do to a crank than measure it.

Have the crank check by a automotve machine shop.

Have it it Magnafluxed, checked for bearing wear, balanced and polished.

They can also R & R and balance the rods.

A shop like RIMCO does not charge very much to do this.

http://www.rimcovw.com/

Buy a good Torque wrench. Sear sells them at a reasonable price. If you have a torque wrench I would is if a local machine shop would chek it for you.

Ken

I don't know how accurate the inexpensive micrometers are but that's not a place where I would cheap-out. You could bring the crank and case to a competent shop and they could measure them for you. Here are some pics that might be of use to you. I'll delete them in a few days or so.

ASR 230

ASR 231

ASR 232

ASR 233

ASR 234

ASR 235