How to upgrade to HO alternator?

[Bullnose010]

Since i have off grid plans (for later) i would like to upgrade my electric system...

Want to start by converting to e-fan/e-waterpump and e-powersteering.

 

And going for an HO (highoutput) alternator like 350/400amp.

But how to setup the serpentine drive to alternator drive? which degree is the best?

Which crannk pully (serpentine) do i need ?

 

1983 F350 351w

 

[Gary Lewis]

I don't have answers on what drive system you need, but you will have to go to a serpentine system to transmit that much power.  Hopefully someone else knows.

But I wonder why you want to convert to electric fan, water pump, and power steering?  It takes more energy to convert from mechanical energy to electricity and then turn that back into mechanical energy.  In other words it is inefficient.

[Bronco638]

I can see switching to an electric fan as it frees up some power because the engine doesn't have to (unnecessarily) turn the fan. I did a conversion on my '85 Ranger and it was pretty simple. But, I am wondering about the e-pump and e-steering. Not quite sure I see the benefit of those. Interested to hear the OP's thoughts. 

[Xr650jkallen]

I am unsure about the serpentine setup, but it might be worth looking at using multiple alternators that are readily available instead of a single custom one. 

[ratdude747]

On 10/11/2024 at 8:13 AM, Bronco638 said:

I can see switching to an electric fan as it frees up some power because the engine doesn't have to (unnecessarily) turn the fan. I did a conversion on my '85 Ranger and it was pretty simple. But, I am wondering about the e-pump and e-steering. Not quite sure I see the benefit of those. Interested to hear the OP's thoughts. 

E-Steering allows for adjustable output (give more boost when on the trail and less when on the road, etc.). And only draws power when in use. 

E-pump is mainly of benefit if drag/dyno racing (kill the pump when making a pull) or for on/off engines (keep coolant flowing when engine is off). The latter is why a lot of modern vehicles use such (along with beefier starters that can handle repeated starts). 

[Bronco638]

20 hours ago, ratdude747 said:

E-Steering allows for adjustable output (give more boost when on the trail and less when on the road, etc.). And only draws power when in use. 

E-pump is mainly of benefit if drag/dyno racing (kill the pump when making a pull) or for on/off engines (keep coolant flowing when engine is off). The latter is why a lot of modern vehicles use such (along with beefier starters that can handle repeated starts). 

OK, so is the cost benefit of either worth it to you? I can see e-Steering if you're off-road a lot (or if it's an off-road only rig).

[ratdude747]

51 minutes ago, Bronco638 said:

OK, so is the cost benefit of either worth it to you? I can see e-Steering if you're off-road a lot (or if it's an off-road only rig).

I didn't say it was (or wasn't) worth it... just why people do such things. To me they're not, which is why my bullnose has none of these. My 1995 ranger has an e-fan swap (which was good for 1MPG), but that's because upgrading alternators was trivial (a 130A 3G bolts in place of the stock 95A without any other mods).

[Bronco638]

7 hours ago, ratdude747 said:

...a 130A 3G bolts in place of the stock 95A without any other mods.

Yeah, not quite the same for our trucks.

[85lebaront2]

Wattage = volts X amps, so if you need a 200 amp alternator to power things you must be planning on some serious power consumers. On the electric fan, the huge one that Ford used on the Crown Victorias, Grand Marquis and Town Cars uses two fuses, a 30 amp for low speed and a 50 amp for high speed, since the starting current draw is quite a bit higher than the running draw, so say maybe around 35 amps high and 20 for low. These fans with their shroud are the sme height as the 1984-97 truck radiators just not quite as wide. As for power, I was testing one, and had my hand holding the shroud with the motor down. the starting torque was enough to almost snatch the corner I was holding out of my hand and at high speed it wanted to lift off the floor.

On alternators, I have a 160 amp 3G on Darth, but I changed to the dual polygroove belts the 1988-1997 460s run and still ended up using a larger alternator pulley as it was burning the belt up on initial starts.

[Gary Lewis]

Bill - I was chirping the polygroove belt on Big Blue on startup with the 130A 3G.  So I changed to the 2 second LRC regulator and that solved that problem.  But the point is that at 130A we are pushing the limit of those belts, and if we had a 350/400A alternator I seriously doubt the belt would handle it.

As for running electrical fans instead of mechanical ones, Wikipedia says: "At medium speeds efficiency of today's alternators is 70–80%."  And Assun says "Brushless motors have higher efficiency rates of up to 85 to 90."

So if we pick the midpoint in both of those, meaning 75% for the alternator and 87.5% for the motor, the efficiency of turning the mechanical energy produced by an engine into electricity and back into mechanical energy would be .75 x .875 = 66%.  So 1/3 of the mechanical energy is turned into heat and only 2/3 of it turns the fan.

As we've discussed here many times before, it doesn't make a lot of sense to do that if you are looking for efficiency.  But it can be helpful if you have special circumstances, like you are running at low RPM consistently or if you need to turn the fan off when you are going through water.