ArdWrknTrk Posted March 25, 2022 Share Posted March 25, 2022 Bill - Is Darth's alternator a "160" because it has diodes capable of handling that much current? I'm asking because I'm wondering how, or even if, the regulators take the output rating of the alternator into account. Looking at Rock Auto's site I don't see a different regulator for the 95A alternator vs the 130A unit, even though a 95A alternator is shown as standard equipment. (The 165A units appear to take an outboard regulator, and I see no regulators for a 200A alternator.) So do the regulators sense the temp of the rectifiers? Gary, Bill's alternator is a RJM modified model. They had bigger diodes and a thicker copper heatsink. You must remember that 95A is 'small case' (135mm diameter) and the 130A is 148mm diameter. The 130A has a bigger heat sink and bigger fans front and rear than the 95A output version. The different diameter is why I keep saying that if you want a 130A on a V-belt truck you should use the extended pivot (8.25" C-C) version. While the 95A will allow you enough belt adjustment, the bigger case in combination with the 7" ears just puts it too close to the block and bracket. Link to comment Share on other sites More sharing options...
Gary Lewis Posted March 25, 2022 Share Posted March 25, 2022 Gary, Bill's alternator is a RJM modified model. They had bigger diodes and a thicker copper heatsink. You must remember that 95A is 'small case' (135mm diameter) and the 130A is 148mm diameter. The 130A has a bigger heat sink and bigger fans front and rear than the 95A output version. The different diameter is why I keep saying that if you want a 130A on a V-belt truck you should use the extended pivot (8.25" C-C) version. While the 95A will allow you enough belt adjustment, the bigger case in combination with the 7" ears just puts it too close to the block and bracket. Yes, but... Let me rephrase my question. Bill took a 130A-capable alternator and put "bigger diodes and a thicker copper heatsink" in it so that now it can put out 160A's w/o blowing a diode. But the generating part of the alternator isn't different, so in the same conditions it'll put out the same current it did before. Which brings me to my question: Does the regulator sense the temp of the heatsink and cut back on the output current to keep from blowing the diodes? Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted March 25, 2022 Share Posted March 25, 2022 Yes, but... Let me rephrase my question. Bill took a 130A-capable alternator and put "bigger diodes and a thicker copper heatsink" in it so that now it can put out 160A's w/o blowing a diode. But the generating part of the alternator isn't different, so in the same conditions it'll put out the same current it did before. Which brings me to my question: Does the regulator sense the temp of the heatsink and cut back on the output current to keep from blowing the diodes? Bill didn't "take" anything. He traded someone for a NIB 160A rated alternator that Ryan built over a decade ago. Back when RJM was a going thing I never had any reason to doubt that their products would live up to their hype. My understanding is (from the site documentation) that the 160 got better bearings and a better rectifier. (bigger heat sink and higher rated diodes) on an otherwise new Chinese 130A 3G. But I may be wrong.... I will have to let Bill answer for himself. Link to comment Share on other sites More sharing options...
85lebaront2 Posted March 25, 2022 Share Posted March 25, 2022 Bill didn't "take" anything. He traded someone for a NIB 160A rated alternator that Ryan built over a decade ago. Back when RJM was a going thing I never had any reason to doubt that their products would live up to their hype. My understanding is (from the site documentation) that the 160 got better bearings and a better rectifier. (bigger heat sink and higher rated diodes) on an otherwise new Chinese 130A 3G. But I may be wrong.... I will have to let Bill answer for himself. The alternator I bought was from a member on FTE who had bought it from RJM to use. He ran into a situation of needing the money. I bought the alternator, a good sized chunk of wire and end lugs from him for what he paid for it plus shipping. It does not appear to be Chinese as the quality of everything is very good. I am pretty sure that RJM did exactly what Jim says, replaced the rectifier bridges with higher current ones. These appear to be a 3.8L Taurus/Sable/Mustang etc 130 amp unit right down to the M8X1.25 thread hole in the tensioning lug. The only issues I have had with it are: Belt slip on startup, one set of brushes/regulator and a front bearing failure. This has been on Darth since probably 2010 or earlier. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted March 25, 2022 Share Posted March 25, 2022 The alternator I bought was from a member on FTE who had bought it from RJM to use. He ran into a situation of needing the money. I bought the alternator, a good sized chunk of wire and end lugs from him for what he paid for it plus shipping. It does not appear to be Chinese as the quality of everything is very good. I am pretty sure that RJM did exactly what Jim says, replaced the rectifier bridges with higher current ones. These appear to be a 3.8L Taurus/Sable/Mustang etc 130 amp unit right down to the M8X1.25 thread hole in the tensioning lug. The only issues I have had with it are: Belt slip on startup, one set of brushes/regulator and a front bearing failure. This has been on Darth since probably 2010 or earlier. I think Ryan used the WAI or Lester number, and this is what made me think the basic chassis was Chinese. Frankly I haven't had any issues with the electrical components I've got from DB Electrical. It's not like they can't produce quality. They are tasked with making things to a cheap price. Link to comment Share on other sites More sharing options...
Gary Lewis Posted March 25, 2022 Share Posted March 25, 2022 I think Ryan used the WAI or Lester number, and this is what made me think the basic chassis was Chinese. Frankly I haven't had any issues with the electrical components I've got from DB Electrical. It's not like they can't produce quality. They are tasked with making things to a cheap price. Ok, I think I understand what's on Darth and where it came from. As well as what failures it has had. And I assume it would kick out 160A on a continuous basis if called upon. But would the same generator/regulator combo with lessor diodes and heat sink cut back to 130A? The generating portion of the alternator would be the same, so how would the regulator know to cut the current back to save the diodes? Does it sense the temp of the heat sink? I'm missing something. Maybe I haven't had enough strong coffee today, so I just got a tall Starbucks dark roast and we'll see if there's a dawning in a bit. But if y'all can 'splain it to me... Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted March 25, 2022 Share Posted March 25, 2022 Ok, I think I understand what's on Darth and where it came from. As well as what failures it has had. And I assume it would kick out 160A on a continuous basis if called upon. But would the same generator/regulator combo with lessor diodes and heat sink cut back to 130A? The generating portion of the alternator would be the same, so how would the regulator know to cut the current back to save the diodes? Does it sense the temp of the heat sink? I'm missing something. Maybe I haven't had enough strong coffee today, so I just got a tall Starbucks dark roast and we'll see if there's a dawning in a bit. But if y'all can 'splain it to me... I don't think there's any thermal protection in my stock 130A alternator. There really shouldn't be any way for a '90-'95 Taurus to pull that much current. I do have a LRC regulator. But I don't think it has any current limits, just a 14.6V set point. Link to comment Share on other sites More sharing options...
85lebaront2 Posted March 25, 2022 Share Posted March 25, 2022 Ok, I think I understand what's on Darth and where it came from. As well as what failures it has had. And I assume it would kick out 160A on a continuous basis if called upon. But would the same generator/regulator combo with lessor diodes and heat sink cut back to 130A? The generating portion of the alternator would be the same, so how would the regulator know to cut the current back to save the diodes? Does it sense the temp of the heat sink? I'm missing something. Maybe I haven't had enough strong coffee today, so I just got a tall Starbucks dark roast and we'll see if there's a dawning in a bit. But if y'all can 'splain it to me... Current is limited by the diode capabilities, voltage output is controlled by the regulator. I do not know if the voltage regulator has any temperature compensation, it may though. Current regulation died with the dynamos. Ok, it may be a Chinese unit, the sticker is still on it and it says "World Power Systems" Link to comment Share on other sites More sharing options...
Recommended Posts