M50 alternator, 80A vs 140A

[scottinAZ]

I currently have a 140A alt installed on my motor. Need to know if the 80A is a direct replacement for this unit, as my spare is 80A. would be nice to know I can use it for more than just a paperweight.

Before we start on the 140A is better, I know it has more juice capability, but the car (with the M20) originally had 80A. shouldnt be too much load for it, just want to know if it will physically fit without issues.

[NbAmTwE]

makes sense to me scott
I know I'm installing an 80A with my M50tu. I won't have a radio or anything unnecessary to make the car drive, and that's why I'm not worried about it for my application.

[Lithium]

80-ok

I just put an 80 on my M50TU - it works fine - But with the blower fan on high - lights on and rear defroster going - at idle it just keeps up - so if you live in a really cold place it might not be great when warming up the car - Otherwise - anything over an idle - it has lotsa juice - Go for it!!!!

[scottinAZ]

cool, just wanted to make sure the damn thing fits. was not as concerned about the output, just the physical fit of the alternator.

[Gooch]

It depends what you originally had and if the new unit is a Bosch or Valeo; the pulleys are different. You can swap pulleys to make either work. Some also mount with a longer bolt and nut on the back (if the housing is not threaded), IIRC.

I had an 80 A myself but found a 140 A in the yard and had an issue with the pulleys when I went to bolt it up.

[scottinAZ]

old unit is a bosch with the larger diameter pulley, new one is a freshly remanned valeo with small diameter pulley. not worried about swapping over pulleys, I have the tools for that (if its needed) Also grabbed the mounting bolts so that should not be an issue either.

[Gooch]

You're all set, then.

[nrubenstein]

140A is not inherently better. It's more drag on the motor. If you don't need it, 80A is better.