Y-TRY
I believe this is what is happening to me, I myself have no way to check amperage coming out of the alternator, can someone tell me what it should be reading and an easy way to check it, I think i can get a meter from my brother. currently I'm running the 140 amp unit that came with the front runner system from Vintage air.

change the pulley on the alternator to a smaller one, so it spins more rpms at low motor rpm, this is not the first problem with the front runner set up

Can i get this smaller pully from VIntage Air, what diameter do you recomend?
makes sense that this would help.

i am not sure about the equation to use to figure it out, but any pulley would work as long as it has the same about of ribs.
someone here maybe able to help with the equation to figure out what the crank pulley is spinning at idle and what the alt is spinning currently at idle. then find spec for max rpm on alternator and go as small as you can, without going over max alt rpm at engine wot

The two aspects I learned:

1- The ratio is about 3:1, based on how the alternator companies rate their output. If they quote 140amps, that's at driving speed with 3:1 pulley ratio. If the ratio is altered the amperage also changes. If you have a lower ratio AND an alternator that is weak at low RPM that could be the 1-2 punch that you're experiencing.

2- In this case, peak amperage isn't as important as what it puts out at idle or low rpm. Not all 140-amp alternators are the same. They have power curves. Shop around.

Contact Powermaster as well as Vintage Air to verify what I'm saying and point you in the right direction. Your alternator company should be able to tell you the curve.

My pulleys had about 2:1 ratio but changing them wasn't an option. So, even after swapping to a high-amp/low rpm alternator I have to idle slightly faster than I would normally to compensate. But it really helped me. This was very frusatrating to hunt down. It'd be worth it if I can help someone else.

Still gets hot
 

Well I finally took the car to a local tuner and the car has never run better, the car can sit and idle all day and not get hot at 180* but as soon as you drive it in town slow stop and go up to 40 it gets up to 210*, as soon as it hits 210* it gets a little hesitation and pop going in the carb, it was 94* outside and i didnt have the Air on, hate tho think what would happen if i did that.
It could be I'm over reacting at 210* but I'm scared of braking down again and i would love to run the Air, could i just have a hot blooded motor that will always run on the hot side?
I told my wife last night I need the new Edelbrock fuel injecrted 555 so i wouldnt have this problem any more, she didnt go for it.

I had this exact problem a few years ago, wish I could remember the details. It was fine at idle and as soon as I touched the gas the temps climbed, let off to idle and they came back down. Not a fan issue as it cools fine at idle. In my case the pump was spinning too fast, and I swapped to a bigger water pump pulley to slow the pump down. Problem eliminated.

I think you have the front runner though, and that system has been out for a long time without issues. In my case I had a put together deal and the water pump pulley was too small, spun the pump too fast. Water temps acted like a tach, going up with rpms. I believe it was a Vic Jr water pump, and some March pieces.

Jody

Mine is doing the same thing. Mid nineties and around town stop lights and such it runs between 200-210. Get out on the freeway and 180-195. Now when it cools off into the 70's or 80's it cools easily. I would like it to run cooler but it's not going to happen. 210 isn't going to hurt anything. I put on a Phelonic carb spacer yesterday and it has really helped my hard hot start and hesitation hot.

Hey Jody,

I think I'm going to lose my hair over this one, I wonder if an oil cooler with a fan would make a big difference.

what's your cooling fan set up look like? I am running a fan/shroud combo off a cobra on my 396 and it's sits at 180 or below with the air on. I am running a BS tru track set up as well.