2.7 Alternator into 3.2 engine HELP!
 

Hello,
I have done a 3.2 engine conversion in my 76 911. The engine did not come with an alternator fan or alternator. So i used my original alternator and fan housing from my 2.7 (it was reconditioned last year).

I am finding that the engine alternator is not charging the engine sufficiently. The car still has an external amp regulator. it has been wired directly from the alternator to the regulator.
Data:
at 1k RMP = charge rate of 12.50
at 3k RMP = Charge rate of 12.95

My question is. Does my crank pulley need to be changed to meet with my 2.7 alternator. There may not be enough rotations to meet the alternator needs.

Any help would be great.

Chris

Blue wire at terminal 11 of 14 pin female connector run from VR then to alternator?

Path for blue wire is VR to 14 pin terminal 11 then doubles back to alternator. (2 wires in terminal 11)
Black and brown are direct runs.

Hey timmy2
It has all been wired up ok, its just not charging at the proper rate. Some local electrical guys were saying that the different size in the pulleys could affect the charging rate, by not having enough rotations to effectivley make the alternator work at it's peak.
My alternator fan/pulley is from a 2.7 my crank pulley is from the new engine 3.2.

My question is could this have a n effect on the alternator charging they system.

I had to ask about the wiring, it's what I do... :)
It is possible the pulley ratio is affecting the system, but I would try swapping in a new solid atate VR for $45 or less first, changing the pulleys is a lot more work. :)

Would the voltage regulator affect the charging system that much in charging rate?
would they pulley system affect the charging rate that much?
When you say solid state voltage regulator, do you mean just a normal regulator? my current one is from my 76 engine and it is external. it has 75 amp. the 3.2 requires 90amp. where would i be able to get an external regulator 14v / 90 amp I have tried looking everywhere and cant find anything... Would it be hard to modify my current one?

You are using the original 70 amp alternator so you just need the replacement VR for it.
3 prong plug in solid state is what is readily available as a replacement, they sell them here at Pelican..

. You can't get 90 amps out of a 70 amp alternator without cooking it very quickly.

The voltage regulator controls the voltage output of the alternator. Normally from 13 to 14.5 volts output depending on what the battery limits as a charge rate when functioning normally, 13,5 volts at 2500 -3000 rpm is normal output after starting the engine.

My question is if i change the VR and it begins charging. Would 70 amp be sufficient to run a 3.2 engine to it's full potential? as they require 90 amp

The 90 amp alternator was used to run all of the electrical accessories in the car as well as the draw of the electronics for the engine. I can't imagine the engine needs more than 15 amps available to run the controls on it. Probably only about 5 amps.

Thanks for your help, I'll let you know how i go with the new VR. If that does't work, ill change the pulley on the engine side.

Chris