Breaking Blower Belts

What are all the reasons a roots blower belt breaks?
-detonation
-too tight
-can a belt be too old?

What have you experienced?

 

align me

had one break due to soft mag idler bracket being bent enough to put load on belt incorrectly. after puting new idler bracket on no problems in 3 years . same belt at 40 over.

 

we have busted belts when we have had them too tight. We now check them once they are at running temperature.

 

I put new white stripping in a blower recently and the first run with it the belt broke. It was not lean, proven when we leaned it more for the 2nd run, which was a succesful run.

We don't think we were any tighter then we normally are.

Any ideas on what to do different the next time so this won't happen again? More blower gel? (do you use an entire can on a restrip job?)

 

Has that issue on a new 14-71 re-strip. Snapped the 8MM belt on the first burnout. Replaced with 14MM GT and used the purple "Problem Solver" (PS) belt and never had an issue again.

 

Who is restripping your blowers? sounds like your tollarances are a bit tight, also blower gel does and will help just spray each rotor lobe and your good to go Dave Lowe

 

If only the white strips are being replaced, what control do you have over the tightness?

What can I do to make them looser?

 

first check and recheck your rotor timing

 

give andy a call at littlefields, in my opinion they are the best blower shop you will ever find..Dave

 

other blower belt failure causes

Ignition interrupt Rev limiters if you run one throw all kinds of front loading. The engine is at full throttle, and the ignition is interupted to hold an engine speed. The front of the crank is doing all sorts of contortions within each revolution during that time. Sending angular accelerations and decelerations into the snout and the blower belt. That is also a cause of crank shaft failures and crank hub walking & galling, as well. Throttle delay launch controls are a better choice as they modulate the power in a steady manner.

All the best,
Bob Szabo
916-419-6649
bob@racecarbook.com
www.racecarbook.com
www.airdensityonline.com

 

bad plug wires!

bad plug wires, leaving wires in the cold and dampness during the winter. the cover gets porous, then the wires cross fired.

 

Manifold

If you run a magnesium intake manifold, be sure to check that its flat. I've seen a number of them that can get bad enough, that you can actually bind the blower where you can't turn it. I learned this lesson by blowng off a couple of 14mm belts in less than 3 passes at 25% od. I figured out what it was, but it took longer than it should have. I have a rolling torque on my R980 Whipple. Evertime I re-install the manifold, I check the rolling torque, turning the front drive. If it less than 20 inch lbs, I'm good. If not, I get out the 1 inch steel plate that I had machined true flat, and start sanding. Probably not your problem, but it has happened before.