Best alternator option?

[Rusty_S85]

As for the alternator being able to always provide enough output at idle to keep the battery voltage at 14.4, the 1G can't if you are running the blower on high and the headlights at the same time. In fact, I'm not sure it can w/o the blower motor on High as all the ones I've been around have had the headlights dim at idle, which means the voltage dropped.

And I don't think the 2G can as the info I've seen on its output shows it isn't much better than a 1G.

The real revolution came with the 3G. It has more output at idle than the others have at full tilt.

A 3G alternator obviously puts out more amps than a 1G alternator. There is no doubt about that. I am just not so sure it's as bad as you claim.

I think the main reason for the 3G was to meet the ever-increasing demands of vehicles as they changed to electronic fuel injection and they became more and more electronic. The 1G was used for over 20 years when vehicles still had carburetors and were largely analog, and they were just fine. Again, the one on my [carbureted] truck has lasted for 35 years with only one rebuild and it is still on its original regulator! And that is with the power-robbing HULK of the stock-style positive engagement starter motor. I haven't had to replace my battery any more than I have on any of my newer vehicles.

But maybe I am lucky or something. I just drove my truck and I let it idle while I turned my blower on high with the headlights on, and they did not dim at idle. I am running a rebuilt Motorcraft 65 amp 1G alternator. It was rebuilt by a local rebuild shop in my area about 9 years ago.

But I will freely admit that I am not in the habit of doing that, even with my newer vehicles. I can count on one hand how many times I have ever turned my blower motor on high on any of my vehicles, much less while the headlights were on. I was always taught to make sure everything was turned OFF before starting a vehicle, and to turn off whatever I am not using at the time. It just seems like common sense to me.

I just thought of something: maybe it was because of these old low-po alternators that I was taught that?

Not just that but computers require more exact voltage and a 1G just wouldnt be that good for ensuring a smooth voltage level. It may have been fine with early computers but it sure wont fly today with modern computers with sensors reading 0 to 5v.

My thing is with my sniper, I have to maintain above 11.3 volts for my sniper to function properly. My current 1G will drop down to 11.9 - 12.1 volts with the AC on at full idle but bring the rpm up just a couple hundred rpm and voltage is right back around 12.9 - 13.1 volts.

Dont get me wrong I am not knocking the 1G, my 1G has been running my truck for the last 15 years with no problems of leaving me stranded or leaving me with a dead battery. But with more electrical systems I dont know if I would want to trust it as much as I did before especially now that I am throwing sensors into the equation that run on the 0 to 5v scale like late modern computer controlled vehicles do.

I dont know which route I will go. I seriously could grab a 70A 1G and let it ride and see how that does, upgrade to a 90A 3G or go all out with the large case 130A 3G which everyone claims has the proper 8.25" ear spacing for use with pivot mount trucks like ours.

[LARIAT 85]

Not just that but computers require more exact voltage and a 1G just wouldnt be that good for ensuring a smooth voltage level. It may have been fine with early computers but it sure wont fly today with modern computers with sensors reading 0 to 5v.

Dont get me wrong I am not knocking the 1G, my 1G has been running my truck for the last 15 years with no problems of leaving me stranded or leaving me with a dead battery. But with more electrical systems I dont know if I would want to trust it as much as I did before especially now that I am throwing sensors into the equation that run on the 0 to 5v scale like late modern computer controlled vehicles do.

I will buy that.

Then of course, is this:

But one thing I did notice that I never tried to see if its a weak regulator or what, at full idle with AC on around 550 rpm the AC blower motor and headlights lose some power. When I go to leave a redlight and I just step on the throttle the moment the rpm comes up slightly my headlights brighten slightly and my blower motor speeds up. That could also very well be the fact I am running at 550rpm without a step up solenoid where OE spec calls for 675 rpm with AC.

My thing is with my sniper, I have to maintain above 11.3 volts for my sniper to function properly. My current 1G will drop down to 11.9 - 12.1 volts with the AC on at full idle but bring the rpm up just a couple hundred rpm and voltage is right back around 12.9 - 13.1 volts

The missing step up solenoid (solepot) may have made the difference.

I have one on Lucille. When the air conditioner is turned on, my solepot is adjusted to kick the idle up to 675 RPM. I have the normal curb idle set at 600 RPM. Without the solepot, the compressor would drag the normal curb idle speed down to about 450 RPM - and it would act the same way yours does.

I can't tell you how many times I have heard someone say that the solepot "isn't really needed." Yes, it IS needed, and this is one very good reason why.

There is much more going on with these old carbureted systems than most people realize. If more people (I don't mean you) would respect these older engines by making sure ALL of the proper components are in place and adjusted correctly - and not dismissed as "smog junk" and discarded simply because they don't like the way they look or understand what they do - I am convinced that there wouldn't be near as many people abandoning their carburetors for expensive fuel injection systems.

 

[Rusty_S85]

Not just that but computers require more exact voltage and a 1G just wouldnt be that good for ensuring a smooth voltage level. It may have been fine with early computers but it sure wont fly today with modern computers with sensors reading 0 to 5v.

Dont get me wrong I am not knocking the 1G, my 1G has been running my truck for the last 15 years with no problems of leaving me stranded or leaving me with a dead battery. But with more electrical systems I dont know if I would want to trust it as much as I did before especially now that I am throwing sensors into the equation that run on the 0 to 5v scale like late modern computer controlled vehicles do.

I will buy that.

Then of course, is this:

But one thing I did notice that I never tried to see if its a weak regulator or what, at full idle with AC on around 550 rpm the AC blower motor and headlights lose some power. When I go to leave a redlight and I just step on the throttle the moment the rpm comes up slightly my headlights brighten slightly and my blower motor speeds up. That could also very well be the fact I am running at 550rpm without a step up solenoid where OE spec calls for 675 rpm with AC.

My thing is with my sniper, I have to maintain above 11.3 volts for my sniper to function properly. My current 1G will drop down to 11.9 - 12.1 volts with the AC on at full idle but bring the rpm up just a couple hundred rpm and voltage is right back around 12.9 - 13.1 volts

The missing step up solenoid (solepot) may have made the difference.

I have one on Lucille. When the air conditioner is turned on, my solepot is adjusted to kick the idle up to 675 RPM. I have the normal curb idle set at 600 RPM. Without the solepot, the compressor would drag the normal curb idle speed down to about 450 RPM - and it would act the same way yours does.

I can't tell you how many times I have heard someone say that the solepot "isn't really needed." Yes, it IS needed, and this is one very good reason why.

There is much more going on with these old carbureted systems than most people realize. If more people (I don't mean you) would respect these older engines by making sure ALL of the proper components are in place and adjusted correctly - and not dismissed as "smog junk" and discarded simply because they don't like the way they look or understand what they do - I am convinced that there wouldn't be near as many people abandoning their carburetors for expensive fuel injection systems.

Of course, my truck doesnt have it as mine is a dealer AC, I did source a used solenoid and bracketry for my truck but I never installed it. I thought of installing it on my Summit carb but now that I am going fuel injection I am going to go into the programming and set it up where my idle speed will be 550 rpm (hopefully I can maintain that speed with my aftermarket cam) and when the AC request is signaled I will have the AC kick function disabled and have it switched to an idle up feature where with the AC request signal my idle up will be to 675 rpm.

So with this in mind I wont need the kicker anymore. But for me I keep asking myself on what route I want to go cause I am still heavily on the fence on this.

Part of me says to say screw it and get the 70A 1G alternator and run that since its bolt in and I wont have to add extra wires. Other part of me says to go with the 90A 3G to get better amperage output at idle as well as a 14.5 voltage set point. Then there is another part of me that says if I do 3G then just go with the 130A and get the 10 second or what ever the highest delay soft start regulator is and swap it in.

For me I am abandoning the carb cause the fuel injection is so much easier to tune. With this I can take it to a dyno and they can plug their computer in and make changes on the fly. Carb you have to disassemble and change jets for example to tune and around here, you show up to a dyno shop with a carb they tell you they will do 3 dyno pulls for $200 but they wont do any tuning as they dont mess with carbs. The other plus side for me is the ability to change my idle speed to where I want on the fly, having a idle kick up without having to have the actual kick up solenoid, the ability to have it plugged in where I can idle the engine up at specific temperatures, then there is the AC functionality where I can program in where at wot I can kill the AC compressor for passing then when I let up off the throttle the compressor will kick back in.

Below is what I was playing around with in my computer program for my sniper and I dont know if I will keep it like this but this is how I basically will be setting up my idle speed.

1000 rpm at -40*F sloping down to 900 rpm @ 29*F down to 575 rpm @ 99*F. Then I have 575 rpm through 237*F and then it starts to slope up to 700rpm and remain 700rpm from 306*F and up. The ramp up from 237* to 306* shows I should be from 575 to around 675 around 250*F. This should provide a function similar to OE vacuum switches did where timing was advanced when the engine hit a certain temp to speed the engine up to try and cool the engine down. That is my idea with the sniper to mimic old ford Tech using modern aftermarket tech eliminating troublesome vacuum switches.

But on topic of the alternator, honestly I still dont know. I am still struggling with that aspect on what I want to do. I got about 4 or 5 feet of 6ga charge cable from american wiring from a rewire job I did at work it was left over charge cable, would be perfect for my truck as I shoudlnt need more than 3 feet between alternator and solenoid. I also got a spare fuse holder and 175A fuse from this same job, as american autowire wanted me to daisy chain two 175A fuses together for the charging system. I didnt do that so I got the stuff to properly do my setup on my truck without spending money on the charge cable or fuse holder. Just dont know if I really want to do the upgrade. I know my truck isnt stock but its also not super upgraded when it comes to the electrical system.

[FrazerJames]

Of course, my truck doesnt have it as mine is a dealer AC, I did source a used solenoid and bracketry for my truck but I never installed it. I thought of installing it on my Summit carb but now that I am going fuel injection I am going to go into the programming and set it up where my idle speed will be 550 rpm (hopefully I can maintain that speed with my aftermarket cam) and when the AC request is signaled I will have the AC kick function disabled and have it switched to an idle up feature where with the AC request signal my idle up will be to 675 rpm.

So with this in mind I wont need the kicker anymore. But for me I keep asking myself on what route I want to go cause I am still heavily on the fence on this.

Part of me says to say screw it and get the 70A 1G alternator and run that since its bolt in and I wont have to add extra wires. Other part of me says to go with the 90A 3G to get better amperage output at idle as well as a 14.5 voltage set point. Then there is another part of me that says if I do 3G then just go with the 130A and get the 10 second or what ever the highest delay soft start regulator is and swap it in.

For me I am abandoning the carb cause the fuel injection is so much easier to tune. With this I can take it to a dyno and they can plug their computer in and make changes on the fly. Carb you have to disassemble and change jets for example to tune and around here, you show up to a dyno shop with a carb they tell you they will do 3 dyno pulls for $200 but they wont do any tuning as they dont mess with carbs. The other plus side for me is the ability to change my idle speed to where I want on the fly, having a idle kick up without having to have the actual kick up solenoid, the ability to have it plugged in where I can idle the engine up at specific temperatures, then there is the AC functionality where I can program in where at wot I can kill the AC compressor for passing then when I let up off the throttle the compressor will kick back in.

Below is what I was playing around with in my computer program for my sniper and I dont know if I will keep it like this but this is how I basically will be setting up my idle speed.

1000 rpm at -40*F sloping down to 900 rpm @ 29*F down to 575 rpm @ 99*F. Then I have 575 rpm through 237*F and then it starts to slope up to 700rpm and remain 700rpm from 306*F and up. The ramp up from 237* to 306* shows I should be from 575 to around 675 around 250*F. This should provide a function similar to OE vacuum switches did where timing was advanced when the engine hit a certain temp to speed the engine up to try and cool the engine down. That is my idea with the sniper to mimic old ford Tech using modern aftermarket tech eliminating troublesome vacuum switches.

But on topic of the alternator, honestly I still dont know. I am still struggling with that aspect on what I want to do. I got about 4 or 5 feet of 6ga charge cable from american wiring from a rewire job I did at work it was left over charge cable, would be perfect for my truck as I shoudlnt need more than 3 feet between alternator and solenoid. I also got a spare fuse holder and 175A fuse from this same job, as american autowire wanted me to daisy chain two 175A fuses together for the charging system. I didnt do that so I got the stuff to properly do my setup on my truck without spending money on the charge cable or fuse holder. Just dont know if I really want to do the upgrade. I know my truck isnt stock but its also not super upgraded when it comes to the electrical system.

Not to hijack, but someone mentioned adding dual belt pulley for 3g alternators. Where does the second belt generally work off of?

[ArdWrknTrk]

Not to hijack, but someone mentioned adding dual belt pulley for 3g alternators. Where does the second belt generally work off of?

The crankshaft pulley.

I mean that's the driving one. Anything else would be just overwhelming whatever belt was on there.

But that's the issue.

You need to find a crank pulley with equal sheaves.

Otherwise you're trying to drive the alternator at two different speeds.

I sent Gary my dual sheave alternator pulley, because I don't seem to need it.

I'm not driving a big winch or a 3000W inverter.

The 2000W inverter I have seems ok with my single belt and battery.

[FrazerJames]

The crankshaft pulley.

I mean that's the driving one. Anything else would be just overwhelming whatever belt was on there.

But that's the issue.

You need to find a crank pulley with equal sheaves.

Otherwise you're trying to drive the alternator at two different speeds.

I sent Gary my dual sheave alternator pulley, because I don't seem to need it.

I'm not driving a big winch or a 3000W inverter.

The 2000W inverter I have seems ok with my single belt and battery.

Got it. I guess I was assuming the crankshaft has all the belt spaces used up already.

Still real fresh to these. Really real fresh.

 

[ArdWrknTrk]

Got it. I guess I was assuming the crankshaft has all the belt spaces used up already.

Still real fresh to these. Really real fresh.

Generally they do.

But depending on how it's set up you can have two belts around the water pump and alternator with one to the power steering, or some other configuration.

There's a myriad of crankshaft pulleys and this has been subject of Gary's 8 page micro-analysis before so I won't rehash all that.

[Gary Lewis]

Not to hijack, but someone mentioned adding dual belt pulley for 3g alternators. Where does the second belt generally work off of?

Jim is right - crankshaft pulley and I have an 8-page microanalysis of the subject somewhere. But to summarize, both pulleys are hard to find. Most alternator and crankshaft pulleys I found had a different belt size for one groove vs the other. But that's not going to work, for several reasons. One, you aren't able to get both belts tight at the same time. Another, they are going to want to run at slightly different speeds.

But, you can find the pulleys.

[ArdWrknTrk]

Jim is right - crankshaft pulley and I have an 8-page microanalysis of the subject somewhere. But to summarize, both pulleys are hard to find. Most alternator and crankshaft pulleys I found had a different belt size for one groove vs the other. But that's not going to work, for several reasons. One, you aren't able to get both belts tight at the same time. Another, they are going to want to run at slightly different speeds.

But, you can find the pulleys.

The pulley I had came from the L&L alternator mounting kit I bought through JBG.

Many auto electric places sell those alternator pulleys.

I'm pretty sure I've seen them on Texas Industrial Electric's site.

They have a vast array of relays, switches and such.

 

[Gary Lewis]

The pulley I had came from the L&L alternator mounting kit I bought through JBG.

Many auto electric places sell those alternator pulleys.

I'm pretty sure I've seen them on Texas Industrial Electric's site.

They have a vast array of relays, switches and such.

I think I'd start with finding the crankshaft pulley and then find an alternator pulley to match because the crank pulleys have a limited range. We have a page on pulleys that will help: Documentation/Engine/Pulleys.

But what that page doesn't tell you is the size of the grooves or sheaves. And in my hunting I found that most crank pulleys have different sizes for the two grooves you'll want to use.

If the crank pulley is off Dad's engine, like I think it is, then I'll look for an ID # on it. That might be a good starting point.