Shifting alternator with shorter fan belt


It’s been a while since anyone yelled at me for unauthorized mods, so I figured it was time.

I’m going to experiment with a shorter alternator belt.

My alternator is at the limit of it’s adjustment range and the belt isn’t very tight. The belt is loose enough that if I pull on it I can move it along. I put a new belt on a couple months ago, but the behavior didn’t change.

A secondary problem is that on the old style radiator the return hose is pretty close to the alternator fan. The alt fan cutting thru the coolant hose has cost a number of us lost engines over the years. That’s why the rule change allowing metal motormounts. This problem of alt fan next to the coolant hose problem is exacerbated if the alternator is at the end of it’s adjustment range, which mine is.

So I got to thinking that the easy fix would be a belt that was a teensy bit shorter. Apparently the OEM belt is 965mm long. I just ordered a belt that is 15mm shorter. All else being equal that would move my alternator 7.5mm inboard, but since my belt is too loose maybe I’ll get only 5mm. Still, being able to properly tighten the alt belt and getting the alt fan 5mm farther away from the coolant hose is cool. Part # A-SPZ950


Just happened to stumble upon this picture and remembered this thread… interesting solution.