I always set my v-belts up so that there was about .250" play up and down. Tight enough to keep the belt working but not too tight to stress the shaft/bearings the pulley was attached to.

I just bought a belt tension gauge from KRC pumps. The instructions advise 140lbs of tension when new and 110 after run in. This is incredibly tight. My old method yields about 65lbs after run in.

I change out my belts too often to see a problems with the belts and I am reluctant to leverage the pulley shafts that much.

What is the consensus?

Tight enough not to slip...... That's all it needs. Anything more just stresses the bearings. If they never slipped at 65, no need to go higher.


Darrell.

Hey your finger is crooked jk


I have a tendcy to over tighten my belts. I prob need to buy one of those tools

It also depends upon what percent of the radius of the pulley is contacted by the belt? When I went with a crossover system the alternator belt now contacts about half way around instead of a 1/4 to 1/3. If you ever get a peak at them at 5K rpm you will see they are moving up and down alot if too loose.

Actually, that is what started the whole process. I could see that the PS belt was contacting a cam driven water pump hose only at high RPM. Swapped to the KRC recommended smaller pulley and bought the gauge at the same time. Still, 140lbs is extremely tight.

I am pretty sure that the shafts and bearngs can take all the belt tension you can put on them. What kills bearings in alternators, water pumps, etc, is loose belts. At high load/high rpm the belts start to slip, creating high temps and THAT is what kills bearings, it cooks the lube out of them.

I will have to get a longer leverage bar (hickory axe handle) as the 12 incher I carry in my tool box only gets me to about 100lbs.

What about the spring tensioners on the supercharger's, what kind of pressure do they see? Also on a cog style, what kind of pressure?