Using 2 alternators .....

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Brooks James

Brooks James

VET, CPT, Huey Medevac Pilot
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I am using the " one off theme" and aircraft style redundancy on my 70 Dart. I Want to use 2 alternators on it to make the engine more symmetrical, more pleasing to the eyes. I saw the alternator sticking out away from the engine making it
Asymmetrical. I notice that the bolt holes at the front of the heads (mangum) , were in the same position. Im going to fabricated 2 brackets, 1 for left and 1 right. I will have to raise the alt on both sides as the power steering cap will be too tall and hit the alternator on the left side.
Im assuming that that I will need 2 voltage regulators. And possibly Schottke diodes to
Make the current from the alt to the battery
Only flow in one direction. im also thinking that because the MSD6al will be used without a ballast, that when the 2nd alternator is switched on , it will provide a fatter spark for the plugs a more than enough for the electronics. ????????
 
Any gains from hotter spark will be more than lost in the extra drag from an extra alternator, and that extra weight will keep you on the ground no matter how far you stick your hand out the window.
 
MSD only draws what it needs, typically 1A per 1000 RPM, so another alternator wont provide it any more power as 1 will usually work just fine. Many hi watt car stereo installs use multiple alternator installs. You could mount the alternator low to offset the PS pump location. Im not sure 2 regulators are needed. The parasitic loss on an extra alternator is gonna be minimal as they are both gonna be running equally under rated at ~50%.
 
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Just out of curiosity- dual mags? I understand you can’t walk home so redundancies- but why mags? No belt to break or will the alternator freeze up in those temps? I’ve never owned an airplane so trying to understand.
Thanks!
Syleng1
 
Interesting idea. Will the alternators fight each other? Never thought about this before….

Diodes will drop the voltage, will that be a regulator issue?
 
Can you say overkill!

If you check your voltages when you are at maximum draw and it is greater than 12.6v you don't need more generation capability.

If you really want higher voltage under a particular condition get a variable voltage regulator and crank it up to 11


Devices only draw the current they need, not the max they are rated at. (Heater coils and incandescent light bulbs are the exception)

If you just have to do the dual alternator, I don't think you will need any special electronics. If one alt and voltage regulator is putting out a bit more voltage than the other they combo will find its own level.

Two batteries in parallel gets 2x the capasity and will both be at the same potential.

Think 2 locomotives each one adds power to the system.

If you want a few more hp. Disconnect the field wire to the alternator. No charging from the alternator but also no load on the engine
 
if you're just making it pleasing to the eye,don't hook it up,less parasitic drag and don't have to worry about extra wiring.
 
You cannot make something that is round.....more round.

It takes power [ not much, but some ] to drive the alt. So if you are spending money to improve engine performance, & then take away performance with an unnecessary alt, then it does not make much sense...
 
Mike69cuda said:
Interesting idea. Will the alternators fight each other? Never thought about this before….

Diodes will drop the voltage, will that be a regulator issue?
Click to expand...
I might not need a diode, i was thinking that a one way current flow diode for safety
 
Bewy said:
You cannot make something that is round.....more round.

It takes power [ not much, but some ] to drive the alt. So if you are spending money to improve engine performance, & then take away performance with an unnecessary alt, then it does not make much sense...
Click to expand...
My main priority is a spare alt
Think redundancy
It would be great if I could also get more
Benefits from dual alts
 
Bewy said:
You cannot make something that is round.....more round.

It takes power [ not much, but some ] to drive the alt. So if you are spending money to improve engine performance, & then take away performance with an unnecessary alt, then it does not make much sense...
Click to expand...
Bewy said:
You cannot make something that is round.....more round.

It takes power [ not much, but some ] to drive the alt. So if you are spending money to improve engine performance, & then take away performance with an unnecessary alt, then it does not make much sense...
Click to expand...
See post 21
 
Dana67Dart said:
Can you say overkill!

If you check your voltages when you are at maximum draw and it is greater than 12.6v you don't need more generation capability.

If you really want higher voltage under a particular condition get a variable voltage regulator and crank it up to 11


Devices only draw the current they need, not the max they are rated at. (Heater coils and incandescent light bulbs are the exception)

If you just have to do the dual alternator, I don't think you will need any special electronics. If one alt and voltage regulator is putting out a bit more voltage than the other they combo will find its own level.

Two batteries in parallel gets 2x the capasity and will both be at the same potential.

Think 2 locomotives each one adds power to the system.

If you want a few more hp. Disconnect the field wire to the alternator. No charging from the alternator but also no load on the engine
Click to expand...
Variable regulator, what a great idea !!
Thats better than my thinking to use rheostats/potentiometers off the main feed wire from the alts
 
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