how do you measure rod bolt stretch

[MAXIBOY]

normally just torque rod bolts but arrow recommend measuring rod bolt stretch hows this done when installing rods in engine cheers

 

[benji&eka]

not quite with you, do you need to measure how much the bolts have stretched?
if so just put a digi caliper on 'em

 

[Jonny1]

Nip the bolts up to start with, and then with either a micrometer (and a small ball bearing for the thread end of the bolt) measure the length (vernier calipers, even digital are not really accurate enuff). Then simply tighten and remeasure until you reach the required stretch.

Alternatively, there is a specific tool for the job, not sure what it's called (probably rod bolt stretch gauge or summut) which takes form of a 'C' shape with a ball at one end and a dial gauge at other. Ball and dial gauge contact either end of the bolt, and you measure stretch that way as you tighten.

Did make a tool myself, useful edition to a tool box. Let me know if you get really stuck.