Boost My Charge Rate, Please!

[multimopes]

I have a 73 RR clone with a 440 in it. Over the years I have been upgrading and fixing stuff like everybody here. One thing leads to another and it goes on and on. Well, I upgraded my cooling system with a high output pump, larger radiator, and of course larger and more powerful electric fans (2) of them. During the course of this I cooked a voltage regulator, and eventually a year later the stock 60 amp alternator decided that a diode in the rectifier set became leaky which in turn prompted me to upgrade the alternator. I bought and installed a Power Master 95 amp alternator and it works great, just not enough at idle. It is fine when one electric fan runs, (at idle) (14 or so volts),; however, when I sit too long and the other fans kicks on, the voltage drops to 11.5 or so until I step on the throttle a little then it comes back up. I have tried different voltage regulators and all do the same. Is there an aftermarket regulator that has the ability to properly compensate for a big load at idle like this. God forbid if it was at night in a traffic jam with the wipers on! It would be really nice if someone made an aftermarket voltage regulator with a computer brain like the new cars have. By the way, I contacted Power Master about a smaller pulley for it to go faster at idle and no soap (for us Mopar folks). If it was a GM or Ford or any other yessir, good to go! Please lead me to the path of Righteousness lest I become even more senile! Thankee, thankee in advance!

 

[black64]

You could spin the alt faster with a smaller diameter alt pulley to increase output at idle. Powermaster should know what output curve your alt is and if you know what the current draw is when the loads on at idle should be able to recommend the pulley you need to get that output at idle. Worth a try.

 

[bm02tj]

Have someone machine a pulley for alternator or try to locate larger pulley for crankshaft
Also you could add fast idle solenoid to bump the idle up when needed

 

[451Mopar]

You could spin the alt faster with a smaller diameter alt pulley to increase output at idle. Powermaster should know what output curve your alt is and if you know what the current draw is when the loads on at idle should be able to recommend the pulley you need to get that output at idle. Worth a try.

As mentioned above, it is not the regulator, just the fact the alternator only produces a fraction of its rated output at lower RPM. You need to know your crank to alternator pulley ratio, and the maximum safe RPM for the alternator and peak engine RPM. For example of the max safe alternator RPM is 12,000 and your engine peak RPM is 6,000 then you can run a crank to alternator pulley ratio of 2:1. If the alternator can handle 18,000 RPM, the the crank pulley can be 3 times larger than the alternator pulley making the alternator spin 3x engine RPM and putting out more power at low engine RPM.

 

[multimopes]

Thank you for the responses. As stated, I tried to get a smaller pulley from Power Master, & they don't make one for Mopar alternators. I do have the specks on the alternator, maybe if they label the shaft diameter, I could get one from Summit, which is where I bought the alternator, although I doubt it. I don't know any local machine shops and they probably would want one of my internal organs to cover the cost, lol; but...Thinking along those lines, with a little research on line, If I can find a smaller diameter pulley with a smaller diameter shaft hole I could drill out the damn thing on my drill press.
I don't know my crank to pulley ratio as my rig is a butchered former race car but the motor is not much over stock. I would never worry about over spinning the alternator as I wouldn't abuse it like that, no really high RPM's. Funny thing is I can get a larger diameter pulley made for race engines to slow it down some. I always like to try the easy way out first. I actually bought a manual choke cable to rig up something like a slide plate that I could activate with it to pivot something between the throttle stop after stepping lightly an the gas. Not looking for more electrical stuff like a solenoid, electrical harness is still factory and half of dash gauges disconnected. This should be a shout-out to aftermarket companies to make an out of the box, solid state or even an adjustable voltage regulator. Maybe even a universal one adaptable to any older vehicle. Hell, if this was a Chevy or Ford, there are a whole boatload of alternatives made and cheaper and easier. By the way, my battery is in the trunk! Any other suggestions are not only welcome, but if you are ever in N.W. Joisey, & stop by to help this old man out, you can have all the beer you can drink!

 

[oldbee]

Thank you for the responses. As stated, I tried to get a smaller pulley from Power Master, & they don't make one for Mopar alternators. I do have the specks on the alternator, maybe if they label the shaft diameter, I could get one from Summit, which is where I bought the alternator, although I doubt it. I don't know any local machine shops and they probably would want one of my internal organs to cover the cost, lol; but...Thinking along those lines, with a little research on line, If I can find a smaller diameter pulley with a smaller diameter shaft hole I could drill out the damn thing on my drill press.
I don't know my crank to pulley ratio as my rig is a butchered former race car but the motor is not much over stock. I would never worry about over spinning the alternator as I wouldn't abuse it like that, no really high RPM's. Funny thing is I can get a larger diameter pulley made for race engines to slow it down some. I always like to try the easy way out first. I actually bought a manual choke cable to rig up something like a slide plate that I could activate with it to pivot something between the throttle stop after stepping lightly an the gas. Not looking for more electrical stuff like a solenoid, electrical harness is still factory and half of dash gauges disconnected. This should be a shout-out to aftermarket companies to make an out of the box, solid state or even an adjustable voltage regulator. Maybe even a universal one adaptable to any older vehicle. Hell, if this was a Chevy or Ford, there are a whole boatload of alternatives made and cheaper and easier. By the way, my battery is in the trunk! Any other suggestions are not only welcome, but if you are ever in N.W. Joisey, & stop by to help this old man out, you can have all the beer you can drink!

I like the "all the beer" thing,lol. Maybe you need to go back to oem fan,shroud,etc. and then it'll still be discharging at idle with just wipers,heater fan like they all did back in the day. I haven't changed my charging system except for " Well's"(?) v.reg & original style alternator, course haven't added any add-on electrical either.

 

[multimopes]

Thank you Old Bee, I wish I had all the stock stuff to go back to. Unfortunately, I got a car that was stripped of all such stuff for the race track. Of the few stock pieces I got, they offered me the back seat which would no longer fit as the roll bar legs would have to go right through the back section. That reminds me, I crawled under the roll bar cross bar behind the front racing buckets to clean the rear area and hurt my back, which hurt for dern near 2 weeks! This getting old crap sux! By the way, I just checked Summit, Jegs and 440Ssource and Power Master for pulleys and not only struck out, but noted that they don't give shaft diameters either, for any of them! Hold that criticism, I looked a different way on Summit and they did give the bore size, I just don't know what size my Power Master Alt shaft is and they don't list that on their own site!

 

[multimopes]

Oh, I also forgot to mention the alternator I got has 2 grooves as I was planning on putting A/C in the car some day! So it makes choices even slimmer!

 

[Shorthorse]

Like bm02tj said, you could go for a larger crank pulley. A quick look at Summit shows two, 2 groove pulleys, 5.25" & 6.5" diameter.
Measure the diameter of your alt pulley and the diameter of your crankshaft pulley. Do the math and you will know what ratio you have now. Run your car with the loads on and using your tach and voltmeter, get an idea of what rpm brings your volts to a satisfactory level at idle. Do the math again to select the proper diameter crank pulley. Just keep in mind what 451Mopar said and check with Power Master about the max rpm's for your alternator.

This might be useful -
http://www.440source.com/pulleyscrank.htm

 

[multimopes]

Thanks Shorthorse, I will do just that. I have been working every day since I posted the original. Haven't had the blue beast out in almost a month and it's only gonna get colder out now. I wrote down a bunch of data from Power Master when I spoke to them but I don't recall them saying anything about max rpm's at all, but if not I will speak with them again. It's possible I even have a spare (larger) crank pulley at home. I think mine is a 6", not sure. They gave me a mixed bag of stuff when I bought the car and I believe that the spare pulley was for a small block (318) that was originally in it and didn't fit but that was years ago. I work rotating shifts so I don't know what or where I am half of the time. It's supposed to be nice tomorrow so I will hopefully get a chance to measure and check my pile of notes. Maybe I can sneak in a quick drive and thrash the car a little before I go to work. It would be nice if the crank pulley was all I had to change and it's most likely easier because I think the alt pulley is a press fit, not sure. I seem to recall the crank pulley I have on it now has 2 different size pulleys on it; are they possibly reversible? Now I will be thinking about it all night instead of sleeping and I don't get home until almost midnight. Hark, me thinks perhaps there is light at the end of my tunnel and hopefully it ain't just a freight train commin my way! Thank you Metallica!

 

[5.7 hemi]

Ditch that alternator and go with the Denso alternator and brackets! Much more output at lower rpm’s and you can get them in different amps. I have 2, 1 at 70 amp and the other at 120.

 

[multimopes]

Are they a direct bolt in or must they be adapted some how or have custom bracket? Also, are they compatible with factory regulator or do they have their own built in? Are there directions for needed electrical system mods? What about alignment issues with other pulleys such as water pump? Are they available with a dual pulley? Damn, do I sound like a skeptic or what?
Sounds good otherwise. I must always try the cheapest way out first as I have a light wallet and holes in my pockets! lol

 

[5.7 hemi]

http://arengineering.com/home-page/alternator-kits/

 

[multimopes]

Thank you, I will check them out!

 

[multimopes]

5.7,
I just checked that link and only see 60 amp alternators. Also checked 440 source, (a vender) and they only offer the 60 amp. Do you have a model or other number on the 120 amp unit? I presume it mounts using the same kit. I don't want to go back to 60 amp unit if I can help it. There is no rush on this, take your time. I don't like to put any body out. Thanks again.

 

[5.7 hemi]

eBay is where to find the 120 amp Denso alternator. They are both the same physical size, take the same plug, and can be had with a dual pulley on it. Let me check there. Be right back.

 

[5.7 hemi]

https://m.ebay.com/itm/4Runner-Truc...3A46fa29fd15f0aa46a91c97eafffecd4a%7Ciid%3A27

 

[5.7 hemi]

I’m still hunting a dual pulley alternator.

 

[multimopes]

Thank you very much. If you find it, I will have to try the ebay link when I get home as it is blocked here at my job!

 

[5.7 hemi]

Can’t find one at the moment, but here’s what ya do. Get a pulley, it will more than likely be 17mm on the shaft, so get a bushing, 17mm to 15mm (that’s what the Denso size is) and your in business.