Quote:
Originally Posted by Firebob
That thought is what stopped me from changing it out. I think my next step will be to pull the elect fan and go back to a belt driven. But, of course that puts me right back where I was when it overheated in the cruise lane last year so I'll not stop there. Following that I think the WP is coming off and I'll do some internal inspections of the divider plates and the cooling tubes/rubber cups to make sure everything there is in order.
This engine has probably 5 thousand miles on it. Everything was done so I know it circulates as good as it can. Radiator is new 4 core brass w/waffle core design( whatever that does). Don't know if I would gain anything by going to a big alum radiator but it may be in cards. Does anybody think a pusher fan would help. It'd be an engineering feat to mount one because of the AC core but if it helped I'd make it happen.
Someone mentioned having the right space in between the shroud and the fan tips. I always figured the least space the better. Not so?
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Once you get the stock fan and shroud back on, I think the biggest player where you'll see a difference is the radiator. While the copper 4 cores do work well, I've always found an improvement with a good 2 core aluminum that has 1 1/4" tubes in every instance I've swapped them in. I've done that with 3 cars here now and every time there is a cooling improvement.
If you've read the thread I started on my fathers car and the Cold Case stuff he installed, you'll see in there that for years he ran a 4 core copper setup with the stock shroud and clutch fan. That engine would push 190 if you ran it hard on the highway, but would cool to about 175 cruising the back streets.
Fast forward to a few months back when he installed the Cold Case setup, take the electric fan experiment out of the equation. He now runs the exact same shroud and clutch fan on the engine he had with the copper radiator. So basically it's just a radiator swap now with the Cold Case. That thing just won't get hot at all now. 3,000 rpm on the highway and it ran 163 degrees for 15 miles, and as soon as we got off and slowed down to 30-35 mph it actually pulled that engine down to 150 degrees. Just CRAZY what a difference that made. So the radiator alone was worth a good 20-25 degree drop in temps vs the copper he had in it. The only thing that electric fan setup did for it was force it to run 195 degrees all the time, and sometimes push over 200 and never cool down no matter how you drove it, fast, slow, stop and idle, those fans just ran constantly and would never shut off, and wouldn't pull the engine down to a reasonable temp at all.
As far as fan spacing, I never pay much attention to that. I run the factory stuff, and what ever it is, that's what it is. They vary quite a bit from one car to the next. Our 1st gen doesn't have much of a factory shroud on it, and the stock clutch fan just lays in it the way the factory did it, it's more out than in. On our A-bodies the fans seem to be more in the shroud then they are out of the shroud. I'd say it's more like 2/3 in and maybe 1/3 out. It's the opposite of the 1st gen. But it's factory stuff and that's just the way it is. I just roll with it. Never poses any kind of issue at all.
On water pumps, if checking impeller clearance gives you a better feeling, then by all means I'd do it. I never check them, never have in over 30 years of replacing them. I've run them all just the way they show up. I just make sure the rubber seals are replaced and the plate is in good working order. Never had an overheating Pontiac that was related to any water pump issues. I believe you're going to find your biggest changes in the radiator and fan/shroud setup.