Posted By: kbmadness
Bigger Alt. Pulley - 07/04/08 03:57 AM
Where can I get a bigger pulley for my altenator. I believe mine is a 3 inch and I need a 4 to 5 inch. Does anyone know which model might have what I'm looking for, I have a 340.
Bigger Alt. Pulley
Posted By: Junky
Re: Bigger Alt. Pulley - 07/04/08 02:45 PM
Quote:
Where can I get a bigger pulley for my altenator. I believe mine is a 3 inch and I need a 4 to 5 inch. Does anyone know which model might have what I'm looking for, I have a 340.
Too add, did Mopar alternators have different size pulleys for our Mopars? There are after market underdrive and overdrive pulleys out there, but what about stock pulleys?
Posted By: stumpy
Re: Bigger Alt. Pulley - 07/04/08 03:50 PM
If you slow it down it won't charge like it should and if you speed it up you may end up spinning the solder out of it. What are you trying to do?
Posted By: RapidRobert
Re: Bigger Alt. Pulley - 07/04/08 05:02 PM
you have a PM
Posted By: Pacnorthcuda
Re: Bigger Alt. Pulley - 07/04/08 05:11 PM
Quote:
If you slow it down it won't charge like it should and if you speed it up you may end up spinning the solder out of it. What are you trying to do?
"spinning the solder out of it" New terminology! Not sure what it means though....
Posted By: Junky
Re: Bigger Alt. Pulley - 07/04/08 05:30 PM
Quote:
If you slow it down it won't charge like it should and if you speed it up you may end up spinning the solder out of it. What are you trying to do?
Can't remember where I saw it, but something like a 10% difference between pulley sizes for our old mopars. I'm trying to find an inexpensive way to up the amps at idle with a stock alternator so it stays charging to keep lights from dimming/flickering. I've done everything I can with the wiring, but still dim (sometimes flickering) lights at idle. Even if I run relays for the head lights, still gonna have dim or flickering tail lights, tac light and dash lights. Under-drive (larger) pulleys are easy to find.
A 10% decrease in pulley should not be a problem. It doesn't hurt them running the engine constantly at 3,500 RPM's down the highway in stead of 2,500 RPM's. That's over 30% difference and it doesn't hurt the alternator. Yes?
Seems like there was or is a difference in pulley size with and without A/C. No?
Where am I wrong?
Posted By: stumpy
Re: Bigger Alt. Pulley - 07/04/08 07:27 PM
The windings on the rotor are soldered and if they get hot enough they soften the solder enough to "throw" it off at high rpm. Doesn't happen often but does happen. It looks like you caught some tin foil in the alt and chewed it up.
Posted By: 451Mopar
Re: Bigger Alt. Pulley - 07/04/08 07:44 PM
To speed the alternator up, you waant a smaller pulley. The alternator speed is the ratio of the crank pulley diameter divided by the alternator pulley diameter times engine RPM
If the crank pulley is 7" and the alt pulley is 3.5, the ratio is 2:1 so if the engine is at 1000 RPM, the alternator is spinning at 2000 RPM.
This is good for getting power out of the alternator, the problem is if your engine spins 7,000 RPM the alternator is at 14,000 RPM (given the 2:1 ratio.) Not all alternators can handle the really high RPMs, the centrifical (sp) force on the windings at high RPM can cause them to sometimes come loose. On the race engine, I chose to use a Denso alternator because it is rated to 14,000 RPM.
If the crank pulley is 7" and the alt pulley is 3.5, the ratio is 2:1 so if the engine is at 1000 RPM, the alternator is spinning at 2000 RPM.
This is good for getting power out of the alternator, the problem is if your engine spins 7,000 RPM the alternator is at 14,000 RPM (given the 2:1 ratio.) Not all alternators can handle the really high RPMs, the centrifical (sp) force on the windings at high RPM can cause them to sometimes come loose. On the race engine, I chose to use a Denso alternator because it is rated to 14,000 RPM.
Posted By: convx4
Re: Bigger Alt. Pulley - 07/05/08 01:29 AM
Did you add a better ground to each headlight when you added the relays to the factory wiring? I added relays and better grounds to my 65, and it helped ALOT . I am not afraid to drive at night any more.
Posted By: MoparforLife
Re: Bigger Alt. Pulley - 07/05/08 01:59 AM
Quote:
To speed the alternator up, you waant a smaller pulley.
Yep if you want to increase the charge rate you will have speed up the alternator and that will take a smaller alternator pulley.
Posted By: NachoRT74
Re: Bigger Alt. Pulley - 07/05/08 02:11 AM
Quote:Quote:
To speed the alternator up, you waant a smaller pulley.
Yep if you want to increase the charge rate you will have speed up the alternator and that will take a smaller alternator pulley.
+1
Posted By: kbmadness
Re: Bigger Alt. Pulley - 07/07/08 02:25 AM
I'm trying to slow my water pump down. I have tried just about everything that I can think of to fix the over heating problem. The guy who dyno my car says that the water pump is too fast.
Posted By: GoodysGotaCuda
Re: Bigger Alt. Pulley - 07/07/08 02:30 AM
Quote:
I'm trying to slow my water pump down. I have tried just about everything that I can think of to fix the over heating problem. The guy who dyno my car says that the water pump is too fast.
Do you run a thermostat, what water pump and radiator? How did he diagnose the water pump is 'spinning too fast'?
Posted By: Anonymous
Re: Bigger Alt. Pulley - 07/07/08 02:33 AM
Regardless of whether changing the speed on the water pump will solve an overheating problem, changing the alternator pulley WILL NOT change the water pump speed.
Only thing that will slow down the pump is:
a smaller crank pulley,
ore
a larger pump pulley.
Only thing that will slow down the pump is:
a smaller crank pulley,
ore
a larger pump pulley.
Posted By: MoparforLife
Re: Bigger Alt. Pulley - 07/07/08 02:35 AM
Quote:
Regardless of whether changing the speed on the water pump will solve an overheating problem, changing the alternator pulley WILL NOT change the water pump speed.
Only thing that will slow down the pump is:
a smaller crank pulley,
ore
a larger pump pulley.
I agree with that. Some body is misleading you if you were told that changing the alt. pulley would slow the pump down. I sure wouldn't go back to him.
Posted By: earlybee
Re: Bigger Alt. Pulley - 07/07/08 05:23 AM
Posted By: kbmadness
Re: Bigger Alt. Pulley - 07/08/08 08:34 AM
I have tried just about every different over heating idea that is known to man. The guy where I get my car dyno at suggested trying twomore things. 1.) bigger alt, pulley, 2.) Weld shut the opening where the cap is on my aluminum radiator. Use a puke tank that has a radiator cap and will hold about a half gallon of coolint. This will eliminate air pockets that cause over heating.