Belt driven fuel pump problems

[AH55]

I wanted to see if I could get some ideas from you guys. We run a Rons black belt driven fuel pump block mount (off the water pump) and it has the small half inch gilmer belt on it. The best that I can tell the pulleys are lined up and both of them have ridge lips on them to keep the belt on. Well, we have thrown the belt 3 times this year with the last one being saturday night costing us a transfer spot. It's usually thrown and not broken as it has been hanging around the bottom mandrel when we've came in, but last night it was gone. We do run it a little snugger than most as I thought this might be insurance against throwing it, but it doesn't seem to help. On a side note which may be related, we were sitting in lineup before this race with the belt issue, and I noticed my idle was really high and my fuel prussure was 6 pounds when its usually 3 at idle.

Not sure what the deal is but any help or experiences you've had would be awesome. Thanks,
Armond

[mod51]

never had much luck with these kept throwing belts...finally switched to mechanical pump.....but yeah if the mount is the least bit off the belt comes off......

I would check the bottom mandrel for strightness...this is where we had the most issue,,,,,good luck

[dirttrackrocker]

I just switched to a belt drive and haven't had any problems. I couldn't get a mechanical to last more than 6 races (alcohol). I agree with checking the mandrel and make sure it is straight.

[AH55]

mod51, I would LOVE to run a mechanical pump, but I have the new style block with no hole in it. My engine builder was telling me that it can be drilled, but the motors got to be dissassembled and it sounds sketchy anyway.

Kevin, How loose do you run your belt? Most everybody around us runs them real loose...just kind of scares us, but maybe it has to be that way.

I did just eyeball the aligment of the bottom mandrel pulley. I guess I need to run a straight edge down there to try and get them dead nuts on. Thanks for the help guys.

[dirttrackrocker]

I keep it just tight enough that I cant take it off without loosening the pump. If you keep it tight, it will wear out the seal on the front of the pump. Also make sure your motor mount bolts are tight. If the motor moves side to side, it will jump also.

[AH55]

Thanks, Kevin....we'll give that a shot this weekend.

[AH55]

Well, it ended up being a harmonic balancer that was out of round and making the mandrel turn funny. We put a new balancer on and diddn't have a problem...knock on wood. Thanks for the help guys.