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  #16 (permalink)  
Old 06-10-2014, 10:38 AM
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Yep, air dam under the core support is just a 3" tall or so piece 3.5-4 foot wide, hangs straight down from bottom of radiator core support to help create a low pressure area behind the radiator under the car.

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  #17 (permalink)  
Old 06-10-2014, 07:35 PM
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Chevykid90, I never had any luck running a thermostat. Some guys took the center out and just ran the outside housing, but that didn't work for me either. The problem seemed to be, with the stock pulleys, that the water just goes thru the radiator too FAST. It doesn't have time to get properly cooled when the revs are up. I had much better luck just running the smallest size restrictor that comes in the set of three (if I remember right the sizes are 5/8", 3/4", and 1").

Also, don't ever run the "flex-a-lite" style fans. When you get the revs up the blades flatten out, and they don't pull the air you need. Blew up one of the best engines I ever raced with one of those damn fans. Replaced the engine and used a 4 blade steel fan, everything else was the same, and never overheated the engine in that car again (the Camaro in my avatar).

I would suggest to get rid of the electric fan on the radiator and run a 4 blade steel fan on the waterpump. This Monte Carlo had an engine very similar to what your running, I ran a Griffin copper 4 core radiator (can't remember now if it was the 27" wide or 31" wide, a 17" steel 4 blade fan, the radiator was mounted 1 1/2-2" from the fan, no air dam or shroud, I used the smallest size restrictor in the set, and the car never ran hot on the hottest nights of the season. Actually, on the cooler nights it needed to run a little warmer!



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Old 06-10-2014, 08:33 PM
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As long as the thermostat flows enough, there's no reason you shouldn't be able to run one and still keep the motor cool. BigEd36 does have a good point about the fan though. If you can't get enough air rammed through the radiator after you get an air dam, etc. on there, swapping from the electric fan to an engine driven one might be enough to band-aid the problem (the engine driven fan, combined with the force of whatever air is blowing through the rad already, will probably move enough air across the radiator to keep it cool, while the electric setup relies almost solely on air flow from the vehicle's movement at higher speeds).
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Old 06-10-2014, 08:49 PM
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Quote:
Originally Posted by chevykid90 View Post
I don't run race fuel. Just non ethanol premium. The next step is to build an air dam. Not sure if it is a sign of air going in the wrong places, but my hood does lift quite a bit going down the straights. "The center bows up" when I build the dam should I have it scoop air from under the bumper also or just seal the bottom and have it scoop from the center? It's the older nose with the aluminum bumpers not the sleeker looking newer ones.
The center of the hood lifting gives me a clue that air is being trapped in the engine compt.. so lets figure out a way to vent that engine area.. Also as the guys have suggested the air dam will help as well..

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Old 06-11-2014, 01:54 PM
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. Yes, anything blocking hot air from leaving the engine compartment near the exhaust that can be removed?

. First thing I think of for overheating is checking to see if lower radiator hose sucks flat when engine is revved up... system pressure and/or a spring in that hose supposed to keep it open...

. Rich mixture may be still burning in exhaust ports/headers/manifolds creating more heat... proper A/F ratio may be cooler...

. Iron heads 'heat soak' at constant WOT and is hard to avoid... a rear coolant crossover or coolant supply added at rear of intake manifold could also help...
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Old 06-11-2014, 03:07 PM
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I have learned to first, pull on one of the fan blades. Anytime my belts slipped before the motor rotated - it has been too loose and slips at race rpm.

Measure your pulley diameters and calculate the reduction. I looked through several stock diameter pulleys back when I first started to find anything remotely similiar in size. Easiest to just pick up a matched aluminum set. With your single pass radiator and V belts you will want to go with a 1 to 1 pulley setup. You may be able to remove the thermostat for better flow with the 1:1, you would need to experiment. Also, you should almost have to remove the radiator to get at the fan bolts (spacing within an inch).

I had to buy a new radiator last month. Different combo's can work depending on your budget. I ran an older single pass aluminum and the 19" GM 4 blade (other 4 blade fans are not the same) with a 1:1 V Belt system, no shroud. Cooled fine when everything was tight before the radiator needed attention, but the big fan was hard on keeping belts tight and I felt I may have been giving up some hp in a low hp class. I replaced it with the same size 2 pass radiator, 30% reduction Serpentine and a 15" Flexa-lite (8000 rpm) fan with shroud. Stewart cast iron WP. Runs a little warmer, builds up to 210 but seems to stay there so far in summer temps.

Last edited by FirstLight7; 06-11-2014 at 03:37 PM.
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  #22 (permalink)  
Old 06-12-2014, 10:59 PM
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Old 07-29-2014, 01:50 PM
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Haven't been able to give a good update because the next race I went out for I smacked the wall on opening lap of main so I couldn't get a good judge of how hot it would get. Since then I pulled the engine put and swapped transmissions to a powerglide and in the process lowered the engine so that I could put on a mechanical fan. Just had a race last Saturday, car ran awesome and didn't get above 220. I left the electric fan on just to have it and never needed to turn it on. Also I got a stock thermostat and cut the center out so it had about a 5/8 opening. Before it was pretty much unrestricted. I also got an underdrive pulley that it 5" diameter.
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Old 07-29-2014, 02:28 PM
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Quote:
Originally Posted by chevykid90 View Post
my hood does lift quite a bit going down the straights. "The center bows up"
Hot air wanting out with nowhere to go. A no-cost mod is to space the rear of the hood up an inch or two with some wooden spacers to allow hot air to escape. Try it.
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  #25 (permalink)  
Old 07-29-2014, 02:35 PM
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454, what turns your crank?
 

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The hood doesn't bow up like it used to now. I think by lowering the engine down and leaving the hood scoop on the hood and not closing it off helped with that. Having the fan on it too could have helped that maybe.
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