LO3BIRD

After stuffing a little torque under the hood, I find I can't run my A/C without hitting 230 (all old SBC heads are somewhat prone to cracking in the middle cylinders, reverse cooling was a good idea I think). Without A/C I'm at 190-210. New stock aluminum radiator. Everything old is new, sig shows specs. Stock LO3 electric fan, but my problem is there on the highway too.

Air dam is in place, but it looks bent inwards (from hitting parking stops). Wouldn't it work better slanted forward? I've not seen what a new one looks like.

I guess the Griffen radiator is the way to go, just curious what other people are getting for temps in thirdgens with above stock motors combined with A/C in hot weather and what they did to get them.

Jstcrzyengh

iTrader: (2)

I am going with the griffin radiator, stewart water pump, dual SPAL fans along with a 180 thermostat... Make sure to throw new hoses on there, like the "blue" hoses and have the block flushed. This should allow you to easily run with the ac on. In fact you may need to run with it on just to keep the temperature up.

rezinn

I run at about 180 is 90 degree weather with a relatively new 3 core copper radiator and stock water pump. I bought a stewart stage 1 pump but never needed it. Don't really use the a/c much but I don't remember it ever getting over 210ish.

The air dam positioning may be sort of important, but you don't need to have it slanted forward. Have you made sure that the radiator isn't blocked at all, and that the stock plastic pieces are in place to direct air over it?

LO3BIRD

Maybe the stock air dam is straight down? Radiator is brand new aluminum stocker. Engine block is also new (rebuilt). All plastic/fan stock stuff is in place. My Miloden hi-flo water pump didn't seem to do too much, but the matching hi-flo 160* stat made a huge diff (installed it first). The stock 160's had the motor "running" away over 245.

I've heard good things about the Griffen's, but also some not so great cooling stories. Plus there's 2 that seem to fit our cars, the 1" and the 1.25" ($190/$290). Before I dump that cash, I'd like to know if I'd get at least 10-15 degree drop with A/C on and which Griffen model would do the job.

Blue hoses? Never heard of those. But I don't like my lower hose, it's not re-enforced (no spring), and 4 auto places couldn't get me one that was, including a speed shop.

Jstcrzyengh

iTrader: (2)

I believe they are GM blue hoses. Try summit or jegs. They are high temp hoses, highly insulated.

I really like the stewart pumps, but thats me. If I recall (since I tore my car apart for the build) the air dam should be pointed forward a bit to kind of scoop air up, though I may be wrong.

I believe both griffin and Be cool have "drop" in radiators for our cars ($400+) That's the route I am going so I don't have to fab too much and have the radiator stick out anymore, since I am going wit hthe dual SPAL fans I need that extra clearance

rezinn

The air dam doesn't "scoop" air up. On my car it's always been pointed straight down.

I think maybe you should look into a dual fan setup and again make sure the radiator isn't obstructed at all.

I've actually heard that high flow pumps aren't all they're made out to be, but show improvement over a worn stock pump easily.

How many miles are on the engine? They tend to run cooler after breaking in.

Jstcrzyengh

iTrader: (2)

By scoop I meant that when driving the air is forced under the car. The air dam having a slight forward incline allows air to go straight up:

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The air is than forced up.

However if you have a straight air dam:



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Air is forced off the sides. Air is being pushed at it ----> but ends up going off the sides, like it would a car. Remember air is going to follow the path of least resistance. On an air dam sticking straight down going straight up is not that path. But that just might be a GM design thing. Like I said it's been about a year since I tore that off when I took the car apart. So the above is more observation than any kind of fact.

rezinn

Look at any new car. You'll see that the air down points straight down. Air doesn't follow the "path of least resistance," that's electricity. Air, like fluids, flows from high pressure to low pressure. The air dam creates a wall that forces the air around it, in effect creating a low pressure area behind the radiator. This causes air to flow through the radiator, not the air dam "scooping" it up. It's a simple application of high school physics; air flowing around an object(the air dam) creates a vacuum behind it, sucking air back toward the direction of flow(through the radiator).

Jstcrzyengh

iTrader: (2)

Well, I was stating a matter of opinion and observation. Also the Vacuum created behind the air dam would be minimal at best, but you decided to go in with the "simple high school physics" remark. You know to respond to a thread, ESPECIALLY after I made the comment that it was observation, the way you did is totally uncalled for. Whatever issues that occured that made you feel that you had to TRY to belittle someone in a response, you need to keep to yourself and not let it come out in a thread. And don't try to say you didn't mean it that way, because there is no other reason for it other than to try to be a j*rk.

LO3BIRD

Thanks guys for the comments. Though, however the air dam functions doesn't really matter too much. Mine is bent inward a little. Maybe that's not ideal but it certainly doesn't explain steady 225* at 70mph with A/C off (I realize a collapsed lower hose would, but even low RPM use around town is a problem). I'm more interested in what components to buy/install so I can enjoy my A/C without cracking my heads.

I've tried retarding the timing, no improvement in temps, only power loss.

Is there really much of a difference between the Stewart/Milodon/Edelbrock water pumps (I realize Stewart has like 4 stages)? It's seems the key is the radiator.

My old stock radiator was less than 1" wide. My new replacement aluminum is 1.2". Fans concern me for in city, but my highway temps are terrible, so fans aren't going to help that.

My condenser is old and some fins are bent. The A/C works super, but perhaps replacing this $116 part would allow more air (although hot) to hit my existing radiator? Getting desperate... One thing I won't do is remove the horsepower, that's a non-option.

BTW, I'm reading water temp from the intake manifold. I was told reading from the head would be lower, though I remain skeptical from my previous experience with this. I figure if it's high at the intake, it's high period.

Jstcrzyengh

iTrader: (2)

Stage 2 stewart most people will tell you will outlast any other pump. Good stuff.

Griffin radiator is good but you will have to custom fit it.

Be cool is expensive, but they show a 20-30 degree difference in their description...

rezinn

It's fine if the air dam is bent a little, it still will be effective. From what I've heard, you won't likely see any improvement with more coolant flow unless your current water pump isn't moving enough volume. That may be the case, though, if its still pretty old. But you'd probably overheat at stop lights if that was true.

I'd still check if your radiator is getting enough air flow through it, that was my problem for a little while after the new engine went in. Removing the condenser would help, but I wouldn't do that until you're out of options. Is there some factory plastic tubing that directs air to the radiator?

The motor is fully broken in, right?

Jstcrzyengh,
Don't be so paranoid, no one is trying to belittle you. I didn't even think you could take my post that way. I don't know why people are so touchy around here. I seriously apologize if I offended you, though. That's the last thing I'd be attempting to do. Just trying to be informative.

LO3BIRD

Without the condenser I'd almost be good to go. But I really need the A/C, and it works great. The condenser has some bent fins, but I'm not sure a new replacement would make such a huge difference.

I had a new stock water pump and 160* stat. Replaced the 160* stat with a Robert Shaw high-flow 160* stat and actually saw the temp needle move down and stay down for the first time. Then I replaced the new water pump with a new Milodon hi-flow cast iron, can't really see much improvement. But when I kick the A/C on, forget about it... too hot.

There's no plastic pieces other than the air dam and the upper/lower supports for the single LO3 electric fan.

The motor probably now has 125 miles on it and it's a .060" overbore. Using Penzoil 10W-30 oil for now and it has a Melling high pressure oil pump.

I expected better temps with my new water pump and new 1.2" aluminum (no-name stocker) radiator. Alas I've searched these forums and haven't found 3rdgen riders bragging about low temps, high HP, and A/C. Starting to think this combo doesn't work well. Only thing really possible to do is replace the old condenser for $116 and/or buy a Griffen 1.25" or other 2" (if it'll fit) radiator for $200ish. Bummed...

rezinn

I'd put a few more miles on it and expect the running temp to drop a bit. When my motor was that new I ran just as hot, can't remember how many miles it took to drop the temp down but I'm pretty sure it was at least double what you've got.