ArdWrknTrk Posted November 27, 2023 Share Posted November 27, 2023 Rusty, 3G's have no need to 'self excite' That's the purpose of the hot in run LG/R wire in the regulator plug At a 3:1ratio the alternator is already turning 2,100 rpm with stock 700 idle Correct, but many companies are now offering the 3G in a one wire configuration in the aftermarket just like the old GM alternators that had an excite wire and was modified into a one wire alternator. On the ratio, that depends on mine with a 3:1 ratio I was looking at 1,920 alternator rpm @ 600 engine rpm. My actual ratio after using a caliper to measure the OD of the pulley came out closer to 2 5/8" not 2 1/2" which put me at 2.71:1 ratio and gives me a 1,600 rpm alternator speed at OE 525 rpm engine speed. 2,100 rpm alternator speed with 2.71:1 ratio like I have would be at 700 rpm engine speed how ever. At the end of the day you dont want to turn these alternators too slow otherwise they wont charge properly but you also dont want to turn them too fast as you can over spin them in upper rpm range of your engine. They are also various statements out there of what rpm alternator speed that the 3G can handle but nothing clear cut. Last I saw was 18,000 was what most can handle but Ive seen that number as low as 15,000 rpm, I hopefully am ok with my setup at 2.71:1 ratio as im looking at 16,762 rpm @ 5500 rpm engine speed which would be my shift point and redline of 6,000 rpm engine speed would spin the alternator at 18,286. With the 3.07:1 to be precise ratio I would have had if it was a 2 1/2" pulley like I thought it was would have put me well over 20,000 rpm at that engine speed. I had no idea that an '82 302 showed curb idle at 525 rpm on the emissions sticker. That seems pretty crazy given how incredibly neutered that engine was in a truck. I guess i only clearly recollect how my '85 GT was supposed to be set. If RJM's pages were still up you would see the video of just how much a properly installed 3G can put out at low rpm. Perhaps Gary or Chris Tubutis has those pages saved locally for posterity? Anyone who wants a 'one wire' alternator cares more about eliminating their harness than having a properly functioning vehicle. Link to comment Share on other sites More sharing options...
Gary Lewis Posted November 28, 2023 Share Posted November 28, 2023 I had no idea that an '82 302 showed curb idle at 525 rpm on the emissions sticker. That seems pretty crazy given how incredibly neutered that engine was in a truck. I guess i only clearly recollect how my '85 GT was supposed to be set. If RJM's pages were still up you would see the video of just how much a properly installed 3G can put out at low rpm. Perhaps Gary or Chris Tubutis has those pages saved locally for posterity? Anyone who wants a 'one wire' alternator cares more about eliminating their harness than having a properly functioning vehicle. I don't have the pages and can't find them on the Wayback Machine. Maybe Chris does? Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted November 28, 2023 Share Posted November 28, 2023 I don't have the pages and can't find them on the Wayback Machine. Maybe Chris does? I remember the two of you discussed it when we realized Ryan was AWOL and the RJM + Old (nee Ford) Fuel Injection websites were going to vanish. Link to comment Share on other sites More sharing options...
Rusty_S85 Posted November 30, 2023 Share Posted November 30, 2023 I had no idea that an '82 302 showed curb idle at 525 rpm on the emissions sticker. That seems pretty crazy given how incredibly neutered that engine was in a truck. I guess i only clearly recollect how my '85 GT was supposed to be set. If RJM's pages were still up you would see the video of just how much a properly installed 3G can put out at low rpm. Perhaps Gary or Chris Tubutis has those pages saved locally for posterity? Anyone who wants a 'one wire' alternator cares more about eliminating their harness than having a properly functioning vehicle. Yep, on my original decal it says for engines with less than 100 miles (brand new trucks) curb idle with A/C off was 525 rpm, with A/C on its 600 rpm. Once you exceed 100 miles it adds 50 rpm to the idle bumping curb idle with A/C off to 575 rpm and 650 rpm with A/C on. Also says fast idle is to be 2,000 rpm which I felt was always way too high, I turned mine down to 1,500 rpm for fast idle. For my new roller build my goal is to shoot for 550 rpm idle speed with 650 rpm idle speed with A/C on. I think my roller cam is small enough that it should be able to smoothly idle at that speed. That is a huge reason why I decided to go with a 3G upgrade is with the sniper efi system it won't be like it is now where idle speed in neutral will be say 700 rpm and will only drop to 500 rpm when in gear. It will always be 500 rpm as that is the target speed, so I need a good alternator to put out amperage at low engine idle speed. Currently I don't have a stepper for my dealer A/C but I will have my idle speed raised up as 550 rpm would be way too slow for the A/C to work efficiently. For power output I filed away the test sheet that came with my alternator that gave a power curve for the output. From what I can see on the chart this is what it appears to be output wise, this is alternator rpm not engine rpm. 1000 rpm : 5A 1200 rpm : 25A 1400 rpm : 45A 1600 rpm : 65A 1800 rpm : 90A 2000 rpm : 102A The following is engine rpm / alternator rpm with the pulley ratio I am running. 525 - 1600 550 - 1676 575 - 1752 600 - 1829 625 - 1905 650 - 1981 So, for me at idle I should be putting out around 65A with the A/C off and with the A/C on I should be putting around 90A out. For me I should no longer have A/C blower motor slowing down when I come to an idle and then speeding back up when I come off idle, and I think 65A at idle is way more than I need as what I calculated I think was around 75A @ 14.5v which also included adding four more 100w auxiliary lights. Sadly there are a lot of people out there that believe one wire alternators are superior. They are also the same people that are running chinese modified GM HEI distributors on their Ford engines thinking they are superior. Link to comment Share on other sites More sharing options...
Ifitaintbroke Posted November 30, 2023 Author Share Posted November 30, 2023 I had no idea that an '82 302 showed curb idle at 525 rpm on the emissions sticker. That seems pretty crazy given how incredibly neutered that engine was in a truck. I guess i only clearly recollect how my '85 GT was supposed to be set. If RJM's pages were still up you would see the video of just how much a properly installed 3G can put out at low rpm. Perhaps Gary or Chris Tubutis has those pages saved locally for posterity? Anyone who wants a 'one wire' alternator cares more about eliminating their harness than having a properly functioning vehicle. Yep, on my original decal it says for engines with less than 100 miles (brand new trucks) curb idle with A/C off was 525 rpm, with A/C on its 600 rpm. Once you exceed 100 miles it adds 50 rpm to the idle bumping curb idle with A/C off to 575 rpm and 650 rpm with A/C on. Also says fast idle is to be 2,000 rpm which I felt was always way too high, I turned mine down to 1,500 rpm for fast idle. For my new roller build my goal is to shoot for 550 rpm idle speed with 650 rpm idle speed with A/C on. I think my roller cam is small enough that it should be able to smoothly idle at that speed. That is a huge reason why I decided to go with a 3G upgrade is with the sniper efi system it won't be like it is now where idle speed in neutral will be say 700 rpm and will only drop to 500 rpm when in gear. It will always be 500 rpm as that is the target speed, so I need a good alternator to put out amperage at low engine idle speed. Currently I don't have a stepper for my dealer A/C but I will have my idle speed raised up as 550 rpm would be way too slow for the A/C to work efficiently. For power output I filed away the test sheet that came with my alternator that gave a power curve for the output. From what I can see on the chart this is what it appears to be output wise, this is alternator rpm not engine rpm. 1000 rpm : 5A 1200 rpm : 25A 1400 rpm : 45A 1600 rpm : 65A 1800 rpm : 90A 2000 rpm : 102A The following is engine rpm / alternator rpm with the pulley ratio I am running. 525 - 1600 550 - 1676 575 - 1752 600 - 1829 625 - 1905 650 - 1981 So, for me at idle I should be putting out around 65A with the A/C off and with the A/C on I should be putting around 90A out. For me I should no longer have A/C blower motor slowing down when I come to an idle and then speeding back up when I come off idle, and I think 65A at idle is way more than I need as what I calculated I think was around 75A @ 14.5v which also included adding four more 100w auxiliary lights. Sadly there are a lot of people out there that believe one wire alternators are superior. They are also the same people that are running chinese modified GM HEI distributors on their Ford engines thinking they are superior. Roller cam? You rich kids make me sick. And no, those chinese hei's are not better. Nor are the one wires. They are easier, and that is the key word. That's also why Sbc's are so popular. They aren't better. They're cheaper. Link to comment Share on other sites More sharing options...
Rusty_S85 Posted November 30, 2023 Share Posted November 30, 2023 Roller cam? You rich kids make me sick. And no, those chinese hei's are not better. Nor are the one wires. They are easier, and that is the key word. That's also why Sbc's are so popular. They aren't better. They're cheaper. Yep roller cam, roller rockers, AFR cylinder heads, Sniper 4150 Stealth. I spared no expense in my engine build as I have no plans to build another engine for my truck lol. Link to comment Share on other sites More sharing options...
Ifitaintbroke Posted November 30, 2023 Author Share Posted November 30, 2023 Roller cam? You rich kids make me sick. And no, those chinese hei's are not better. Nor are the one wires. They are easier, and that is the key word. That's also why Sbc's are so popular. They aren't better. They're cheaper. Yep roller cam, roller rockers, AFR cylinder heads, Sniper 4150 Stealth. I spared no expense in my engine build as I have no plans to build another engine for my truck lol. Did you ever get it dyno'd? That sounds pretty spicy. Link to comment Share on other sites More sharing options...
Rusty_S85 Posted November 30, 2023 Share Posted November 30, 2023 Did you ever get it dyno'd? That sounds pretty spicy. Havent gotten it installed yet. Some of the parts I am wanting to get are still on back order. Like the stainless steel Y-pipe I want to run its currently on back order. Im hopeful that next year will be the year as I only have a hand full of parts to get to be able to install the engine. From there I hope to get a dyno done after I swap transmissions and change rear axle ratios out. My goal was always a modest 300hp which would be over double the power output of the oe smog 302, realistically my specs are fairly similar to the 306 crate engine from blueprint that they rate at 385hp using their in house made non CNC machined heads and slightly larger roller cam compared to my CNC machined Renegade 165 heads that flows more. So from a dyno I expect to see some where around 345 - 380 hp at the flywheel for my build. Im also anxious to see how it will sound as I have OE sized 6" round muffler but its in 2 1/2" inlet/outlet and its a Magnaflow XL 3-chamber muffler and I am going to have a local exhaust shop bend a OE style tail pipe in 2 1/2" vs the OE 2 1/4" Link to comment Share on other sites More sharing options...
Ifitaintbroke Posted November 30, 2023 Author Share Posted November 30, 2023 Did you ever get it dyno'd? That sounds pretty spicy. Havent gotten it installed yet. Some of the parts I am wanting to get are still on back order. Like the stainless steel Y-pipe I want to run its currently on back order. Im hopeful that next year will be the year as I only have a hand full of parts to get to be able to install the engine. From there I hope to get a dyno done after I swap transmissions and change rear axle ratios out. My goal was always a modest 300hp which would be over double the power output of the oe smog 302, realistically my specs are fairly similar to the 306 crate engine from blueprint that they rate at 385hp using their in house made non CNC machined heads and slightly larger roller cam compared to my CNC machined Renegade 165 heads that flows more. So from a dyno I expect to see some where around 345 - 380 hp at the flywheel for my build. Im also anxious to see how it will sound as I have OE sized 6" round muffler but its in 2 1/2" inlet/outlet and its a Magnaflow XL 3-chamber muffler and I am going to have a local exhaust shop bend a OE style tail pipe in 2 1/2" vs the OE 2 1/4" That should be a beast. Don't know if you've seen my build thread, but I'm running ported factory iron. I had a set of Eddy heads, and was going to stroke mine out to a 547ci, but I could not get a hold of the pistons to facilitate that. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted December 1, 2023 Share Posted December 1, 2023 That should be a beast. Don't know if you've seen my build thread, but I'm running ported factory iron. I had a set of Eddy heads, and was going to stroke mine out to a 547ci, but I could not get a hold of the pistons to facilitate that. It sucks that Venolia is gone (by any real measure) Wiseco/Carrillo will make anything you want if your pockets are deep enough. Link to comment Share on other sites More sharing options...
Recommended Posts