Pulley step-back

[Entropy]

Hey all,

Quick technical question I can't seem to find an answer to. How is a pulley's step-back measured for v-belts - specifically for crank pulleys on SBC's. Is it measured to the center of the groove or to one of the edges?

 

[shaun89]

im not sure if this will help,but most all v belts are 10mm wide and have a 36 degree angle if u measure the V on the belt...

 

[Entropy]

Actually, it's the measurement from where the pulley is attached to where the groove is. For instance, with a crank pulley with a step-back of 2 1/2 inches, the groove of the pulley is 2 1/2 inches from where it bolts onto the harmonic balancer. What I don't understand is if that 2 1/2 inches is to the center of the groove or the edge of the groove.

 

[shaun89]

oooo i get it...hmmm, sorry man i cant answer that one...if i had to guess, i would say the top of the groove, it just seems kinda difficult to get an accurate measurement measuring the bottom of the groove. but hey,i could be wrong...

 

[4X4HIGH]

I'm going to say they mean to the center of the groove.