Supercharger belt tension question

[DEANs427]

I am about ready to start my first supercharger installation and am looking for an experienced opinion on the amount of belt deflection recommended. 19 " between pulley centers on the non-idler/adjuster side. 2" gilmer belt with .5 pitch...

[machoneman]

Start looser not tighter!

Some belt deflection notes here:

http://www.chevelles.com/forums/13-performance/163172-6-71-blower-belt-
tension.html

Btw, the second poster is Royce from the old 'Net 54 FE Forum. I say loose as once the engine and blower heat-up, then you set the final belt tension as noted.

This is NOT though what we used to do with drag-only engines (392's, 426's, on alky or nitro) as they needed to be darned tight all the time, hot or cold.

[jayb]

With a toothed belt you don't need a lot of tension, Dean.  I would say 1/2" to 3/4" of deflection in the middle of your span.  Or, grab the belt and twist it; you should get between 45 and 90 degrees of twist with hand pressure.

[DEANs427]

Successful start! Thanks guys,
Dean

[57 lima bean]

Bronco or Gasser vehicle Dean?

[BattlestarGalactic]

You will notice if you get it too tight(when motor warms up), it will start to really whine.  Just keep tabs on it for awhile til you know what it is like.

I got caught in some bad traffic one day with my blower car.  She was really whining loud as everything started to expand from sitting in the sun and not moving.  Lesson learned.

[DEANs427]

slight belt whine came in as engine warmed, will expect more when engine is under load, only in test stand now. have a video but can't get it loaded

[BattlestarGalactic]

The biggest thing you have to worry about is snapping the crank snout off if too tight.  The whine will always be there, but you will notice the pitch of it change as it gets tighter.   Kinda like a guitar string........

[DEANs427]

running a 2" belt to lessen that happening
Steve, long term plan is to install blower motor in the gasser, but putting it in the bronco to get all the bugs worked out