BC high output altinator

bad 68 · Mar 18, 2011

I installed the BC 150 amp alt last fall and I can't get the stock V-Belt to stop squaking on start up. The regulator must read 12 volts and causes it to full pull on start up untill the volts come up, then it quits. Takes about 2 seconds or so. Drives me nuts and make my fine old EB sound like a pile. Any sugestions on the wiring or a better way to belt drive it?

Viperwolf1 · Mar 18, 2011

Bigger diameter pulley or double pulley and belts.

chuck · Mar 18, 2011

That or a surpentine belt. The alt may charge up to 167 amps. Did you look at the chart that came with the alt.? The Alt. was designed for a S-belt. A larger pulley will help but I would think the V-belt going around the crank, waterpump and alt would give enough contact. Do you have a traction belt?

bad 68 · Mar 21, 2011

I know it was desinged for a serp belt but seems like BC wouldn't sell it for a Vbelt setup if it wasn't going to work. I thought about a bigger pully but was afraid it wouln't charge at an idle. I tried a longer powerstearing belt to double belt it, but there wasn't enough contact between crank or waterpump.

Never heard of a traction belt.

Guess I'll try a larger pully and set my idle up if needed.

phred · Mar 21, 2011

Mine squealed a little at start up but I made some adjustments and it stopped. Im sure you have checked but check again. Is the tension on the belt correct, are both alt bolts tight, is the alt pulley lined up parallel with everything else. I found I need to shim mine just a bit to line everything up and the pivot bolt was loose

bad 68 · Mar 22, 2011

It use to squeel, I ran it that way all winter. I just put a new belt on 2 weeks ago and it is good and tight. Still squeels. . The alt. is lined up with the water pump pully with a strait edge. All bolts are tight.

HoosierDaddy · Mar 22, 2011

Not suprised an alt. that powerful squeals on only one belt.

I wouldn't try to hard to tighten it too much , you'll probably just trash the bearings.

hdmc · Mar 22, 2011

I run a 180 amp alt with a v-belt with a larger pulley I don't have no squeal at start up. Shoot rrraaayyy2 a p.m he built my Alternator and told me with the larger pulley it would fine and so far no problems

hdmc · Mar 22, 2011

I run a 180 amp alt with a v-belt with a larger pulley I don't have no squeal at start up. Shoot rrraaayyy2 a p.m he built my Alternator and told me with the larger pulley it would be fine

DirtDonk · Mar 24, 2011

bad 68 said:
...I thought about a bigger pully but was afraid it wouln't charge at an idle...

I wouldn't think these would have an idle problem with charging. They are capable of putting out a pretty good charge even at lower rpms, so you're still way above what you probably had.
That said, yes, you theoretically lower your output at lower rpms, but I've had the squeals too, so I think the trade-off would be well worth it.
Like you said, you can always up the idle a bit. Hopefully though, you won't have to.

Good luck.

Paul

chuck · Mar 24, 2011

I haven't had the problem with V-belts squealing on the alt. sense we put the A/C on the drivers side but back then I found that the traction belts held better. The traction belt is the one that looks like it has teeth. This is how things work. Any alt. will only charge what the load will allow so if your bat. is fully charged and you have nothing on the alt will not charge at any RPM's. But if your bat. is low and you have the A/C on and are running a wench the alt. will try to charge to it's max. Or if the field wire has resistance the alt. will see the bat. as low and try to charge it or if the bat. is not all that good a quick start will take more out of it than normal and the alt. will charge a lot to get it back up.
I have a chart for the 130 amp alt. that was ran before shipping. The alt is called a 130a but the chart shows a max Amps of 163. That is at 6000 RPM! It's not as bad as that because that is alt. RPMs so if you have a 6" crank pulley and a 2" alt. pulley that 163a can happen at 2000 RPMs. At 1000 engine RPMs the alt can put out 130a but shouldn't because the only way that can happen is if your battery is dead and that shouldn't be.
RAAAAAAAY you won't hurt my feelings by correcting me here, I don't want to mislead anyone and bow to your greater experience.

bad 68 · Mar 24, 2011

Ok Chuck here is a little more explantaion. I am running Dual Optima Yellow top batteries, parellel. On start up watching the Volt Meter the belt will squak intill it hits around 13 volts. This only takes about 1-2 seconds. It seems to me the Alt tries to thow full amps at start up, thus slipping the belt. You mention the field wire has resistance but It is the harness kit that you sell so I don't know why it would. Once the engine is running I can pull the 8000 pound winch hard with the sterio cranked(2 amplifiers) head light on and heater fan on high and no problems.

73stallion · Mar 24, 2011

tighten the piss out of it. i have my belt tighter than i'd do a normal one, and i've been doing it like that the past 6 years or so. i've heard people say it puts more strain on the bearings, but i've had NO trouble.

Broncobowsher · Mar 24, 2011

I take it you have the typical 90-120° or so of belt wrap around the alternator pulley.
Could you add an idler pulley to try and bring that up closer to 180° of belt wrap? Any wide smooth serp style will ride just fine on the back side of a V-belt. I have seen a similer setup of something at the junkyard once (factory setup that is). I just remember thinking that was a fix for a squeally belt and I would have to remember that for later.

bad 68 · Mar 24, 2011

I ordered a larger diamater pully thanks to the Tech advise from Raaaaaaay. It will be 3.2" damater compared to the approx 2.6 that the belt rides in now. Chuck if this works you might want to send those alts out with the correct pully in the first place.
Thanks to everyone that responded.

chuck · Mar 25, 2011

bad 68 said:
Ok Chuck here is a little more explantaion. I am running Dual Optima Yellow top batteries, parellel. On start up watching the Volt Meter the belt will squak intill it hits around 13 volts. This only takes about 1-2 seconds. It seems to me the Alt tries to thow full amps at start up, thus slipping the belt. You mention the field wire has resistance but It is the harness kit that you sell so I don't know why it would. Once the engine is running I can pull the 8000 pound winch hard with the sterio cranked(2 amplifiers) head light on and heater fan on high and no problems.

Sounds like a problem with the wire from your key. No matter if the harness is from me and new, a new connection can be bad. A charging volt is 13.8 to 14.2 volts, the lower the volts the harder the alt will charge. 12 volts is considered a dead battery. So my guess is less than 13v would cause the Alt to charge full charge. To find out put a jumper wire from the green/red wire to your battery (+) and start your engine. If it still squeals that is not the problem.

RRRAAAYYY2 · Mar 25, 2011

chuck said:
I haven't had the problem with V-belts squealing on the alt. sense we put the A/C on the drivers side but back then I found that the traction belts held better. The traction belt is the one that looks like it has teeth. This is how things work. Any alt. will only charge what the load will allow so if your bat. is fully charged and you have nothing on the alt will not charge at any RPM's. But if your bat. is low and you have the A/C on and are running a wench the alt. will try to charge to it's max. Or if the field wire has resistance the alt. will see the bat. as low and try to charge it or if the bat. is not all that good a quick start will take more out of it than normal and the alt. will charge a lot to get it back up.
I have a chart for the 130 amp alt. that was ran before shipping. The alt is called a 130a but the chart shows a max Amps of 163. That is at 6000 RPM! It's not as bad as that because that is alt. RPMs so if you have a 6" crank pulley and a 2" alt. pulley that 163a can happen at 2000 RPMs. At 1000 engine RPMs the alt can put out 130a but shouldn't because the only way that can happen is if your battery is dead and that shouldn't be.
RAAAAAAAY you won't hurt my feelings by correcting me here, I don't want to mislead anyone and bow to your greater experience.

LOL, I only want you bending over if you are cute, and a girl. Seriously though, you said it right. I would add that even a dead battery will only take 60amps at a time. Too much resistance for anymore than that. For the most part they are only around 50amps for a few minutes, and down to 25 in 5 minutes.
I also run up 200amp alternators with V belts and dont have any squealing. Hard to keep percise belt tension though, as belts are continously streching a little bit. And it doesnt hurt to check your other pulleys, make sure they are still V grouves, and not becoming U grooves, or that they have polished grooves.

RRRAAAYYY2 · Mar 25, 2011

bad 68 said:
I ordered a larger diamater pully thanks to the Tech advise from Raaaaaaay. It will be 3.2" damater compared to the approx 2.6 that the belt rides in now. Chuck if this works you might want to send those alts out with the correct pully in the first place.
Thanks to everyone that responded.

I would not say he is sending them out with the wrong pullies right now. I send them out with both the small diameter or the big diameter, depending on the application. If you were EFI, and had a smaller crank pulley, you would not be happy with the larger pulley. Hard to expect a supplier to know all that.

RRRAAAYYY2 · Mar 25, 2011

Sorry I missed this thread the other day.

chuck · Mar 25, 2011

I am not cute and not a girl and I said bow to, not bend over

. Thanks for all of you input.....except that bend over part

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