V Belt

[KenF]

The V Belt I bought from SS sure seems awfully narrow, and really rides down low in the grooves. It's a Gates 7490, but it only measures about 5/16" wide, and seems to need adjusting every few weeks. The thread below give dimensions of what looks like a better fit, a 15/32" wide belt x 49.5" long, which should hold an adjustment better. Anyone know that part number? Thanks, Ken

https://www.catmbr.org/VB_forum/showpost.php?p=3176&postcount=2

 

[0neoffive]

What fits

The V Belt I bought from SS sure seems awfully narrow, and really rides down low in the grooves. It's a Gates 7490, but it only measures about 5/16" wide, and seems to need adjusting every few weeks. The thread below give dimensions of what looks like a better fit, a 15/32" wide belt x 49.5" long, which should hold an adjustment better. Anyone know that part number? Thanks, Ken

https://www.catmbr.org/VB_forum/showpost.php?p=3176&postcount=2

I prefer the 3/8" notched belt for alts and the 15/16" notched for genos. Your need for constant adjustment indicates either a run alignment issue causing heat & wear or belt quality.

 

[KenF]

Gates 7495

Installed Gates 7495, much better.

 

[Maliburevue]

Alignment

In the picture you posted it appears your generator sits too far back. I had to add a washer under my generator mounts to more it forward. In the picture attached I am holding a straight piece of wood flush against the front of the fan pulley and it aligns with the front of the generator pulley. You may want to verify your alignment.

Gary

 

[KenF]

In the picture you posted it appears your generator sits too far back. I had to add a washer under my generator mounts to more it forward. In the picture attached I am holding a straight piece of wood flush against the front of the fan pulley and it aligns with the front of the generator pulley. You may want to verify your alignment.

Gary

Yeah, put a straightedge on my water pump pulley, which aligns perfectly with crank pulley, and generator is set back about 3/16". If I shim generator bracket out I may also have to move washer bottle forward a bit. I wonder if they ever aligned from the factory, or if it was a "close enough" design decision.

 

[Maliburevue]

Alignment

Sadly, you're probably right! LOL

Well, it's good to know, I'm not the only one who noticed that. I wonder how many belts have been thrown, before that was discovered.

 

[ABSunbeams]

Belt misaligned

Had the same issue, used a washer to move forward & had to move the washer bottle forward to clear. Sawing thru the bottle was the learning moment.

 

[KenF]

I did a little homework on V Belt alignment, and according to Gates Tech Info a pulley parallel misalignment of 1/2˚ is acceptable, and at 6˚ becomes unstable.
Rule of thumb is 1/2˚ = approximately 1/10" offset per foot. So at 13" between pulleys, mine is a little less than 1˚.
So, I'm sticking with my "close enough" theory amongst the Rootes engineers.
Until I throw a belt, or notice other issues, I'll just leave it. And my 260 rarely gets spun up to 5000 rpm.