Water Pump/Alternator Belt too tight?

[The_Collector]

How tight is the water pump/alternator belt supposed to be on a bp? It just occurred to me i may be tightening it too much. I have thrown 2 belts while racing so of course i make sure they are super tight when I replace them.... how tight is too tight? Or am I throwing them because I'm putting them on too tight and they are shredding or something?

[FestYboy]

you shouldn't be able to take the belt and twist it 90* with your fingers at the longest point. if you can, it's too loose, if you can't get it anywhere near 90*, it's too tight.

you can also use the ruler method (better for V style belts) again at the longest point. span a ruler between the pullies and another pushes on the belt in the middle of the span. less than 1/4" is ideal, but more than 1/8".

[The_Collector]

Thanks for the quick reply, Yeah I can't get it to turn 90 degrees, but the belt is getting pretty hot, it's probably just something i've never noticed happening. I'm just concerned driving it so far and throwing/breaking a belt.

[denguy]

You can tighten it to the point where it won't deflect at all, but your bearings probably won't last very long.

[blkfordsedan]

Make sure your sheaves (pulleys) are aligned properly as well. The sheaves can also wear out due to slipping, which can accelerate the slipping issue & throw belts. Never "roll" the belt into the groove or pry on it to get it on.

[walth]

you can read through this thread too... devon's been having some issues with it lately

http://www.fordfestiva.com/forums/showthread.php?t=37900

[WmWatt]

Deflection should be 3/8" for a worn in belt according to Haynes manual.

[FestYboy]

hence the "no more than 1/4" when installed" (allowes for stretch)