Running hot after UD Pullies

By putting on the U/D pulleys you slowed down the waterpump. If it didnt have problems before the U/D pulleys, put the factory waterpump pulley back on and purchase a new serpentine belt...

-Smoke

The problem is most likely not enough airflow at idle. The best solution is to put in a decent electric fan(For Miami, the Lincoln Mark 8 might be the best bet), and a 130A 3g alternator from a newer stang to charge it. And keep the stock alt pulley, or even put an overdrive one on. You can also run less coolant and more water and add a little water wetter if you haven't tried that already. Does it ever even get to freezing temps down there?

It's probably a combination of the coolant moving more slowly at idle, and the factory fan spinning more slowly. The electric fan(s) may do the trick, but you won't know til you try. And based on your electrical condition, sounds like you'd have to upgrade alternators anyhow. So, you put underdrives on to gain a few HP - mainly above 3500 rpm, and you have to go back and overdrive the water pump, add a new alternator and electric fan to get them to work. I had the same issue - I put the stockers back on and sold the u/d's in the classifieds. They don't work for everyone - and Miami, like Houston and Atlanta, are murder on cooling systems in stop and go. There's no question you can get them to work - the question is how much will you have ended up spending for your 6-15HP (most of which is freed up at higher rpm which you use on the street rarely) by the time all the charging and cooling mods are done? I'd say cut your losses now and invest your money in a different mod. If you lived in Portland (OR or Maine), it'd probably be different - but not in Miami.

Oh - the oil cooler will drop the oil temps, and it might slow down the rate of temp rise in the coolant a bit, but it won't make any appreciable difference at low speeds. If you put it in front of the radiator - the heat rejected out of the oil just taxes the coolant and a/c system that much more. If you put it where the heat coming out of the oil doesn't enter the radiator/a-c condenser, then it has no fan pulling air across it at low speeds. Unless you add a small electric fan to it - in which case you've got even more load on your alternator. I've got an oil cooler on mine placed where the heated air coming off of it passes under the car. Works great on the highway - but around town, unless you put a small fan on it or put it in front of the radiator - not much air moves across it.

Get a 180 t-stat and a overdrive alternator pulley. With a good battery and this combo, you should be good to go.

The newer alternators are much better. You're talking the stock 75A compared to 130A on a 94+ They are a better design too. I switched them on both stangs I had. I picked them up from a junk yard for $50 a piece. The stock one is barely enough for the stock system let alone any additional accesories. On the last stang, I put in a ramchargers.com fan which is a high quaility oem dual fan for only $80. It worked great, and I recommended it to a buddy who likes his as well. I have the Mark 8 fan in my gt, but it was $170 and it's overkill. Underdrive pulleys not only give you 10hp, but improve gas milage as well, and the stock fans are known for cracking, so if it's not cracked now, it will eventually, and they aren't cheap to replace either. As for the oil cooler, unless you are road racing, you don't need it. The hotter oil is also thinner and will give you slightly more hp too. I put a chrome oil pan on my stang just to hold in a little more heat because I mostly just drag race with it. If you want to take the pullies off, that would probably solve your problem, however it won't make you any faster.

Dam double post.

Ralph - didn't intend to imply that it wasn't a bright idea; I've pretty consistently posted that the only way to know is to try them. It just has a better chance of working out in Toronto than it does Miami - if all the rest of the cooling system components are stock.

BTW - I had no trouble at all trading my u/d's for cash and a replacement set of stock pullies; there's always a market out there for the u/d's, and lots of stock pullies laying around that aren't worth anything to people.

Heres what I did got a HUGE aluminum 3 core radiator and an electric fan oh, and 180 t-stat. Solved. The radior was so long I had to cut part of the radiator support to fit it. The best part it was only $230 from the local speed shop. Temps never go above 180.

Hey Ralph, I'm over in the Clearwater area, and have held off on the u/d's just because of the problems you are experiencing. Tampa traffic doesn't compare to Miami, but thanks to the F.O.P's we do get more than our share of stop and go on Highway 19 here. Most of the guys that I have talked to are only running the crank pulley. Some have upgraded to the 130 amp alternator, but are still running the factory size pulley on it. I have ASP underdrives on my truck though, and have no problems with charging or cooling....so I agree with Michael Yount (you pretty much have to try them and see). If I were in your situation, I'd probably skip all the extra costs of an electric fan, bigger/better alternator, etc. and find a factory (or overdrive) alternator pulley and short belt (as suggested by Smokedawg).

electric fan = more hp