Gilmer Drive Belt - Tension?

[GBowman]

I am sticking with the 3/8...saw a thread on another site where they were going with 15mm which was working well. We will see...I do think the pulleys are expanding once hot which makes the belt tighter (which goes against conventional wisdom). I think folks with this set up are used to the cold belt being the tightest and are adjusting for a hot belt and not allowing for pulley expansion.

[RICK LAKE]

V-man Like Jerry been around racing a long time. If the motor is hot we ran between 1/4" and 1/2" of deflection. The problem is wear and tear on the bearings of the water pump and Alt. As long as the belt is not jumping teeth when hot I would leave it alone. Everything tightens when the pulleys, belt, and motor bay cools off. The belt is going to walk unless you have the pulleys all trued and at the same depth on the motor. We used to drill holes in the pulleys to help remove the air trapped with the motor running. This made the motor quieter and I think helped get a better deflection of the belt running. Rick L.

[rpatton3]

Originally Posted by RICK LAKE

V-man Like Jerry been around racing a long time. If the motor is hot we ran between 1/4" and 1/2" of deflection. The problem is wear and tear on the bearings of the water pump and Alt. As long as the belt is not jumping teeth when hot I would leave it alone. Everything tightens when the pulleys, belt, and motor bay cools off. The belt is going to walk unless you have the pulleys all trued and at the same depth on the motor. We used to drill holes in the pulleys to help remove the air trapped with the motor running. This made the motor quieter and I think helped get a better deflection of the belt running. Rick L.

Your water pump speed is 1.3 x crankshaft speed. I found this out after looking on eBay at 1 x 1 crankshaft speed and a 1.5" belt.