Just curious if a 5/8 wide vbelt would work with our crank pulley? I wanted to swap out my alternator pulley and run a 5/8 wide inside groove pulley. I'm guessing it won't but thought I'd ask.
Thanks in advance.
Thanks in advance.
5/8 v belt
- Thread starter gerlbaum
- Start date
Guess a follow up question would be, I've got a lathe. Think there is enough meat on the inside groove of the crank pulley to cut it to 5/8"? I'd like to run a bigger amp alternator (currebtly have a 130a) and I just don't think a single 1/2 wide vbelt is going to work. I also can't see a way to drive the alternator with 2 vbelts (3 groove pulley on the alternator).
Macrobb
Full Access Member
You could always make a new pulley with the lathe - new crank + water pump pulley with a wider groove.
Also, it probably *will* work with a single V-belt; remember, even a higher amp alternator won't be putting out that amperage most of the time. It'll put out quite a bit right after startup, or if you have a winch or something, but other than that, I'd be surprised if it's putting out even 30 amps steady-state.
Alternately, I wonder if you could use some sort of 1/2" "timing belt" style belt - something with cogs/notches instead of just friction.
Also, it probably *will* work with a single V-belt; remember, even a higher amp alternator won't be putting out that amperage most of the time. It'll put out quite a bit right after startup, or if you have a winch or something, but other than that, I'd be surprised if it's putting out even 30 amps steady-state.
Alternately, I wonder if you could use some sort of 1/2" "timing belt" style belt - something with cogs/notches instead of just friction.
I have run wider belts on the pulleys before. If your 1/2" belt is down inside the pulley walls, the larger belt will be up and even with the outside of the pulley or may even stick out just a little bit, but it has always worked ok for me. So you will be buying a 15 series belts instead of a 13 series correct? The 13 is 13mm wide, and the 15 is 15mm wide.
Be aware you will probably need a longer belt if you go with a 15 series belt. The belt numbers usually go 15435 or 43515 for example. 15435 is a 15mm wide belt and is 43 1/2 inches long. On the other number they just move the 15 to the end of the number. 52015 would be a 52 inch long belt that is 15mm wide.
P.S. They do make special regulators you can install that trim the output of the alternator at first start up to prevent belt squealing at start up. You are correct, a single v-belt cannot handle the full output of a large alternator, I am surprised you haven't had any belt squealing with the 130 amp you have already. A single v-belt cannot support the full output of that alternator, partly the reason they went to a serpentine belt system.
Be aware you will probably need a longer belt if you go with a 15 series belt. The belt numbers usually go 15435 or 43515 for example. 15435 is a 15mm wide belt and is 43 1/2 inches long. On the other number they just move the 15 to the end of the number. 52015 would be a 52 inch long belt that is 15mm wide.
P.S. They do make special regulators you can install that trim the output of the alternator at first start up to prevent belt squealing at start up. You are correct, a single v-belt cannot handle the full output of a large alternator, I am surprised you haven't had any belt squealing with the 130 amp you have already. A single v-belt cannot support the full output of that alternator, partly the reason they went to a serpentine belt system.
I found a place that will send me a pre ground hss lathe bit for under $20 to make the v belt larger if need be. I thought that the IDI on buses may have used a 5/8 crank pulley since that is a common size medium duty trucks but I can find any info. Sometimes they make the grooves deep enough to run either a 5/8 or 1/2. Finding the alternator pulley is a breeze, it's the crank one that's been hard to figure out.
Let me tell you about belt squeal with a 130 amp alt on a single V belt.
I’m already running the shorter belt from just the WP. Screams like a banshee until the batteries charge back up then it’s fine. Tighten the belt and it will be good for a couple starts then does it again.
Ambo project did that too, and that was just the stock ambulance package alternatorLet me tell you about belt squeal with a 130 amp alt on a single V belt.
I’m already running the shorter belt from just the WP. Screams like a banshee until the batteries charge back up then it’s fine. Tighten the belt and it will be good for a couple starts then does it again.
