STEVES59

I have a 59 corvette that I built a 425 horse power small block for and i cannot keep this thing cool. I am asking you guys for advise as the c1 guys are mostley pureists and im looking to talk motor head hear. i purchased a dewiits aluminum radiator that mr dewitt swore up and down would cool this engine. I am useing a 5 blade clutch fan set up and a weind water pump the car will keep climing in traffic and when shut off tends to start perculating when im moveing the cars @ 180 degrees Im starting to thing the stock pullys that im useing are not turning the pump fast enough thease pullys are the same ones that came with the car. the engine that was in the car was a junk yard 307 what crank to pump ratio would be optimum for my application? I really dont want to resort to an electric fan and dont feel I should need one. incidentley this cooling system is an open system no overfow tank and a 7 psi cap as all 59s were . Im all ears hear fellas

Gordonm

Can't help much but my setup is around 425 HP. I am running the stock LT1 radiater and all the pulleys are stock. The shroud does have all new seals so it is pretty tight but with a 180 thermostat I can idle in traffic and it just barely touches 200. Most of the time it runs right at 180. Are you using a shroud? Is it sealed up to the core support. Not that it will cause it to run cooler but my cap is a 15 psi cap.

turtlevette

does the fan clutch offer resistance when you try to spin it by finger? Some aftermarket fan clutches don't work like the heavy duty ones.

Is your fan shroud sealed off against the radiator. My shroud has big gaps at the corners that i stuff air conditioning foam in so the air doesn't bypass the radiator. A good suction needs to be created by the fan.

what ratio antifreeze are you using? The less you run in summer the better. I actually drain some antifreeze out in the summer for better cooling especially when on the road course.




[Modified by turtlevette, 7:30 PM 6/30/2004]

jcswm

Unless you've got a newer heator core, I'd stay with the 7lb cap
but I'd try an overflow bottle first..... It sounds like you've got all the right stuff!!! but your glass is 1/2 empty!!!! an overflow tank will ensure your system is full at all times.

Z-man

I'm no expert, but since it stays at 180 when you're moving, the radiator is probably sufficient in size. A few thoughts: maybe it's the fan...

- Are you sure the clutch on the fan works? I ran a flex fan for the last 20 years that really sucked air through and I never had to wonder about the clutch. I don't think you can tell just by watching the fan spin whether a clutch fan is good or not.
- C3s have a shroud that helps the fan draw the air through. Is that something that comes on C1's? If not, you might look into getting one
- Is the pump in good shape (internally)? If not, that could be a problem. If it is good, then the only thing I can think of is experiment with a smaller pulley.

zwede

As mentioned, many fan clutches are junk. As a test you can try a solid spacer and run without a clutch and see if that makes a difference.

The fan needs to be in the right position in regards to the shroud. It should actually be halfway out of the shroud, not alll inside, and not all outside.

I don't think the pump is the problem.

The aluminum radiators from dewitts, becool and griffin are all excellent units and should not have any problems cooling your combo.

I take it you have already replaced the thermostat and verified the accuracy of your gauge?

I'm surprised at the low pressure you're running (not very familiar with C1's). Maybe you should consider changing to a closed system with a 15 or 16 PSI cap and overflow tank. I'm not too crazy about the idea of running big amounts of air in the system as the early open style do. I know that when I change coolant and then start it up I have air pockets and the temp will climb way up there until the airpockets burp out into the overflow tank.

Desertdawg

Go with a closed system. before you try anything else.

mayberg

Yup - I would expect air in the cooling system.

427basketcase

I would stay away from overdriving the water pump with undersize pulleys.
The water needs a chance to cool off in the radiator and by pushing it through too fast defeats the effectiveness of a radiator.
Check to make sure the timing is correct and the fuel mixture is not too lean. These will also effect the engine temp.
Just my two cents.

burners

I agree with what everyone has said. It is important to make sure your fan shroud is properly configured and sealed. I also think that a closed system is the only way you will cool an engine like that. The point about the heater core is a good one. You may want to replace it or at least bypass it and try a higher pressure cap to see if that works.

Tiredol74

Have you tried drillin your thermostat and/or goin to high-flo balanced one?

Wrencher

What you describe is a classic low air flow problem at low speeds that we BB guys have dealt with for years. I'm not familiar with the '59 setup, however. Is it a fixed fan or fan clutch? How far back from the radiator is it? Does it even have a shroud?

You mentioned not being to concerned about originality, so electric fan(s) are the way to go, but your right in that it should cool with some sort of conventional fan. At present, I run a cut down aluminum 7 blade fan and clutch off of a mid '80's Dodge that moves a ton of air and bolts right up to my water pump. Mine only warms up a little (210) in traffic on the hottest days with the A/C on, which I would consider normal. Good luck.

Hans

JBR

No expert here, yet like most have had over heating problems. At high speed,AIR FLOW is a problem, ex. front air dam, foam seals around radiator.hood seal,shroud and fan location, clutch problem. Slow speed,WATER FLOW is a problem, ex. pump problem, bottom hose no inner spring, low fluid, cap too lite #s, thermostate problem, radiator pluged. Hope this helps.

Solid LT1

Your radiator was designed for a 290HP 283 engine. I would check with Tom DeWitt for a possible aluminum drop-in replacement. There are a few guys around here with high HP C1's I am going to a convention next week and will see what they are doing for cooling. I would also check your initial timing because retarded timing can cause high idle tempratures(run at least 8-12 degrees BTDC initail timing at idle.) I run the Edelbrock H2O pump and it has good circulation. There must be a set-up to allow you to solve your problem, possibly in the Street Rod industry but, I would check all the basics first (you aren't running a 400 Small Block where the machinist forgot to drill the steam holes into the heads are you?)

69L68

One thing I had noticed is that my BB is very sensitive to the timing. My two cents.

Steve

0Tom@Dewitt

Steve,

You've doubled the radiator capacity with the aluminum radiator. As you know, nothing else will fit into the stock mounting that will provide any more than we already have. When we are restricted in size by the factory core supports there isn't much more we can do.

You've also double (maybe more) the HP generated in stock engines and most new motors run hotter than sloppy ones. Custom cams and fuel mixtures can be trial and error to find the optimum point since no spec book exists. You might play around in these areas but in the end I think the best solution is going to be an electric fan.

Fans can provide three times as much air flow as an engine driven fan can and this will boost the cooling performance 30%. One problem with fans on C1 cars is that you can't run them with generators. I assume you converted to an alt. when the new engine went in.




[Modified by Tom DeWitt, 5:58 PM 7/1/2004]

Robert N

I really dont want to resort to an electric fan and dont feel I should need one.

I agree. My LT-1 will idle in traffic (caught at every other light commuting yesterday) in 110+ degree temps with never a blip over 180 on the guage regrdless of how hard or long I drive.

incidentley this cooling system is an open system no overfow tank

I have the stock radiator and also have no overflow tank. I do not know what pressure cap I am running.

My shroud is in place and sealed tight, the T-stat, water pump, radiator, hoses, etc are new. I still use the original clutch fan.

I do not think there is an issue in the design, but possibly and issue with one or more components. I would start with the fan clutch as recommended.

Sharky Guam

Yep, two problems come to mind regarding your problem and they both have to do with air. First, no matter which cooling system you have, you need to get rid of the air in the engine..I would pull the upper radiator hose and burp all of that air out.... Then handle the airflow issue. Proper shrouding is necessary on corvettes especially if they retain the stock fan set up. You need to seal the edges of the shroud and make sure that the fan is large enough to properly fit in the shroud opening. I also would try using redline Water Wetter to help bring down the temperature.