Shane T
Member
Just wondering if anyone knows what the maximum operating temperature for these belts? Where can I find out?
Temp ratings on 3VX belts?
- Thread starter Shane T
- Start date
Shawn Forsythe
RIP
Ideal belt temp should not exceed 140 degrees F.
Belt manufacturers often quote the 5-second rule. If you can firmly grasp the belts and hold on for 5 seconds or more after run-in, the belt temp is fine.
Now most belt manufacturers will indicate that the belts can withstand temps greater than this, but that for every 18 degree rise, belt life expectancy will diminish by half, all other things being equal.
Most, if not all TM's take advantage of the fact ttat belts can still work, beyond the max ideal of 140. They simply realize that usual expectancy is 3 years at 140 deg F, and that it will lessen at higher temps. There is also variation a bit among brands.
3vx belts are cogged, so they dissipate heat better than non-cogged designs, and because there is a myriad of variables, belt temp should be observed after run-in.
Belts will generate their own heat, which needs to be dissipated. The mere diameter of the pulleys can have a tremendous effect on the flexion induced heat. Slippage and nature of the belt tensioner can also be a contributor.
Belt manufacturers often quote the 5-second rule. If you can firmly grasp the belts and hold on for 5 seconds or more after run-in, the belt temp is fine.
Now most belt manufacturers will indicate that the belts can withstand temps greater than this, but that for every 18 degree rise, belt life expectancy will diminish by half, all other things being equal.
Most, if not all TM's take advantage of the fact ttat belts can still work, beyond the max ideal of 140. They simply realize that usual expectancy is 3 years at 140 deg F, and that it will lessen at higher temps. There is also variation a bit among brands.
3vx belts are cogged, so they dissipate heat better than non-cogged designs, and because there is a myriad of variables, belt temp should be observed after run-in.
Belts will generate their own heat, which needs to be dissipated. The mere diameter of the pulleys can have a tremendous effect on the flexion induced heat. Slippage and nature of the belt tensioner can also be a contributor.
Shane T
Member
Thanks Shawn, 140 doesn't very high considering all the heat producing equipment in a slide-in unit. I'll bet the ambient temp inside the van is over that. I am going to check the temp with an infrared thermometer. Given the close proximity to the exhaust I won't be surprised if the temp far exceeds 140 degrees. Probably why belts don't last.
Shawn pointed out a huge issue concerning belt slippage and temps. Pulley Diameter. I never thought much of it until I needed to solve my own belt slippage problems. When switching up to larger diameter pulleys all around my problems disappeared. I found driving a 47 blower you need at least a 5 to 5 1/2" pulley to keep the belts in good form. My drive pulley is 8" in diameter and boy does that thing hold a belt. There's so much more surface area for the belt to grip on to.
Ron Werner
Member
MIne are 6" drive and 7" blower. My belts lasted about 6 yrs, just replaced them last summer. I like the idea of the bigger drive sheave. maybe instead of changing my blower sheave I'll change my drive sheave. The 6" drive sheave is about 20 yrs old anyway.
Shane T
Member
I believe both of my shives are 5". The belt length is 33.5 inches long. That a longer belt will run cooler? I have a laser thermometer and my belts are running any where from 200-280 degrees.
Shawn Forsythe
RIP
Shane,
That pulley and distance arrangement is certainly not very conducive to keeping a belt cool. The diameters are small, and the distance between them is pretty short. Add a hot exhaust nearby and you definitely have a "hostile" environment for any belt longevity.
Merely adding distance to achieve a longer "cooling zone" for the belts may not be very cost efficient. Adding diameter to the sheaves is even better. But to do so will definitely require more distance. However, doing so can bring belts closer to a heat source(exhaust), which will negate or even worsen the situation. Cooling airflow may be option. Either direct hot airflow away, direct cooling to the belts, or both.
That pulley and distance arrangement is certainly not very conducive to keeping a belt cool. The diameters are small, and the distance between them is pretty short. Add a hot exhaust nearby and you definitely have a "hostile" environment for any belt longevity.
Merely adding distance to achieve a longer "cooling zone" for the belts may not be very cost efficient. Adding diameter to the sheaves is even better. But to do so will definitely require more distance. However, doing so can bring belts closer to a heat source(exhaust), which will negate or even worsen the situation. Cooling airflow may be option. Either direct hot airflow away, direct cooling to the belts, or both.
Shane T
Member
Since my last post bought a 6" cooling fan from Summit Racing that says it moves 1800 CFM and installed it so that it blows "cooler" air right on the blower sheaves and belts. Added some length to the air chute on the top of the machine which gets the hot air out of the van. I also mounted a Stanley air mover to the ceiling and plug it in most of the time which also get alot of hot air out. Belts(actually now its just one banded power belt) are now staying about 200F. Guess I'll see how long this lasts now. May have to add a cool air duct to the auxiliary cooling fan.
Larry Cobb
Member
Shane;
From our Factory Gates Rep:
"As a rule of thumb, however, most
belts give acceptable service within a range of -30 to 160º F."
We really like the 5VX belt line.
Larry Cobb
From our Factory Gates Rep:
"As a rule of thumb, however, most
belts give acceptable service within a range of -30 to 160º F."
We really like the 5VX belt line.
Larry Cobb
judson jones
RIP
- Joined
- May 5, 2007
- Messages
- 206
Belts
Shawn, Its obvious you know what you are talking about.
For years we have used 3VX belts in order to use smaller pulleys for compactness. We use multipless to meet HP requirementss,have had no problems.
You can get a set of our belts at Grainger for less than $30.00.
The current V price list offers a set of belts & 2 Qts. of oil,2 qts of valve lube ?. at the low price of $465.00.
Good luck, Judson
Shawn, Its obvious you know what you are talking about.
For years we have used 3VX belts in order to use smaller pulleys for compactness. We use multipless to meet HP requirementss,have had no problems.
You can get a set of our belts at Grainger for less than $30.00.
The current V price list offers a set of belts & 2 Qts. of oil,2 qts of valve lube ?. at the low price of $465.00.
Good luck, Judson
