Rewinding Alternators

W

WildKitty

Experienced Member
I went shopping for a 100-125amp alternator for the LeSabre's 300.

The new wiring harness will allow either a one wire or three wire hookup to the alternator. I'm assuming the one wire alternator makes it possible to leave out the regulator.

However after a few hours of going thru books at the parts store, the owner suggested I just have the 65amp rewired to 100 or 125 amps. which would mean keeping the voltage regulator (which is OK, but do I need an upgraded regulator for the increase in amps).

I'm adding a aux battery (in the trunk) so the upgraded electronics (windows, seats, stereo, etc.) can function without draining the main battery.

Open for suggestions here
thanks
Butch
 
Sounds like the harness is made for the '72 & up GM internaly regulated alternator,can you verify this?.The 1 wire option has to be used with a self sensing regulator,the 3 wire will allow the idiot light to function and also will turn on quicker by powering the reg off the ignition switch.This alternator requires removal of the firewall regulator.
Your present alternator can be upgraded to 90 amps or so,but it will have limited low rpm amperage,i dont suggest that for any extended low RPM driving.
Power windows & seats wont require a bigger alternator.Stereo & electric radiator cooling fans will.
If your going to run 2 batteries i suggest an battery isolator as well.You will need to get one compatable to the alternators amperage rating.
I can hook you up with everything you need:thumbsup:
 
good points Jamie.

I do have the isolator, that I had installed in the Wildcat to keep up the spare battery for the stereo system. I will replace it after I get the LeSabre on the road.

I am going with electric cooling fan - I think it draws 8mps. I'm also installing rear view cameras, but they don't draw that much. I'm sure whatever audio system I install will require the extra power to let it play while the car isn't running.

I think I better go with a higher @idle producing alternator.

the wiring harness has the "either/or" wiring for one or three wire alternators. again, I suspect I will need a different regulator.

Thanks for the input
Butch
 
checked the isolator that I had in the Wildcaat; max amp input is 70.

I think my main concern would be the lectric cooling fan.

got to reading/thinking: what HP gain would there be with an lectric water pump?

I am going with an A1 a/c unit, will loose a few horses with that.

One of my hairbrained ideas is to try to run an a/c compressor off the flywheel opposite the starter - don/t see why that wouldn't work.:confused:
Butch
 
Electric water pumps are for racing or short term running only. Unless they have about a 5 horse motor on them. Same with the teeth on the flex plate. If you wanted to run a constant mesh gear train at those rpm it better be built a lot sturdier than the thin metal that a flex plate is made out of and it should be inclosed for some type of constant lubrication system. V belts may not look trick but they are fairly efficient, pretty simple and damned reliable.
 
No free lunch!

On a street engine there would not be a gain with an electric water pump. Lets say for the sake of argument that it takes 5 horsepower to turn your water pump at highway speed going down the road on a hot summer day. The V belt from the crankshaft pulley is supplying that 5 horses. If you take off that belt and put an electric pump on it you now have to supply that 5 horses with electricity. That means that the alternator belt now has to carry more load, probably more than 5 horses cause nothing is 100% efficient, to supply the power to the electric water pump. It works on a drag race engine because you are only running for a short period of time and can use the stored energy in the battery to get you by. 5 horsepower is a conservative estimate of what it will take to cool a V8 engine in an everyday driving type of environment. You are not just circulating the water. You have to pressurize the cooling system to make it work. The pump provides this pressure. The radiator cap is the limiter for most of the system, but pressures inside the block can run higher between the pump and the restriction provided by the thermostat.
 
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