Alternator underdrive pulley

GEM930 · #1 03-21-2012, 03:51 PM

I posted to an older thread about this, but realized it was the rv-10 section only. I'm reposting here in hopes that I might get a larger audience. I looking for an underdrive pulley the standard Lester part # 14684 alternator. Any ideas where to find one or suggestions on size???

Thanks guys! (and gals)!

PerfTech · #2 03-21-2012, 04:18 PM

Quote:

Originally Posted by GEM930

I posted to an older thread about this, but realized it was the rv-10 section only. I'm reposting here in hopes that I might get a larger audience. I looking for an underdrive pulley the standard Lester part # 14684 alternator. Any ideas where to find one or suggestions on size???

Thanks guys! (and gals)!

Are you looking for a larger pulley for the alternator?

GEM930 · #3 03-22-2012, 06:33 AM

Yes, Appearently the standard pully the Lester comes with drives the alternator much faster than need be when used with the large lycoming flywheel.

chaskuss · #4 03-22-2012, 07:44 AM

Gregg,
One source for a larger alternator pulley [3.25" & 4" diameter are popular] would be your local automotive "hot rod" shop. You need a pulley for a 15mm shaft. You could also check with the popular "mail order" hot rod shops like Summit Racing or Pegasus Auto Parts [owned by RV builder/owner Chris Heitman] See

https://www.pegasusautoracing.com/pr...asp?RecID=5548

Charlie

Walt · #5 03-22-2012, 08:34 AM

Installing a larger pulley will likely require a new belt and may also cause interference with the cowl (I know clearance on the 7 is very close between cowl and pulley).

Don Jones · #6 03-22-2012, 08:38 AM

I have a 3" (might be 3 1/4") 15 mm shaft pulley. It is at home, so can't measure it. Let me know if you are interested.

GEM930 · #7 03-22-2012, 04:13 PM

If its 3.25 I might be, let me know. Also please measure the width of the flat area at the bottom of the "v".
Thx!

Bob Axsom · #8 03-22-2012, 04:27 PM

I have the later RV-6A cowl and the standard pulley clears it when it is just sitting in the hangar but I noticesd markings where there had been pulley to cowl contact and knew it was only a matter of time before the cowl was penetrated. I cut off the blade of a SS butter knife and glued it to the inside of the cowl with structural adhesive over the contact marks. Now several years later there is a grove worn in the SS. My neighbor has a slot cut completely through his RV-6A cowl by the alternator pulley. Compared to the airplane, alternators are a throw away part and I would not try to save it at the risk of damaging the cowl.

Bob Axsom

Ironflight · #9 03-22-2012, 07:33 PM

Quote:

Originally Posted by Bob Axsom

I have the later RV-6A cowl and the standard pulley clears it when it is just sitting in the hangar but I noticesd markings where there had been pulley to cowl contact and knew it was only a matter of time before the cowl was penetrated. I cut off the blade of a SS butter knife and glued it to the inside of the cowl with structural adhesive over the contact marks. Now several years later there is a grove worn in the SS. My neighbor has a slot cut completely through his RV-6A cowl by the alternator pulley. Compared to the airplane, alternators are a throw away part and I would not try to save it at the risk of damaging the cowl.

Bob Axsom

I've seen many a cowl with a little "bump" for the alternator pulley - in fact, I've installed a couple of those bumps. Very simple fiberglass work, and you just put it where the groove tells you to....

flytoday · #10 03-22-2012, 08:55 PM

Quote:

Originally Posted by Ironflight

I've seen many a cowl with a little "bump" for the alternator pulley - in fact, I've installed a couple of those bumps. Very simple fiberglass work, and you just put it where the groove tells you to....

And very few people even notice the bump!

A tennis ball with wax paper makes a great bump shaper, pressed into the soft fiberglass from inside of the cowling.