cooling question

[Barnsnake]

What voltage are you showing at speed versus idle. Some gauges are highly voltage sensitive and the problem could be the regulator.

I would also verify the accuracy of the sender & gauge.

If that lower radiator hose has a rubber lining, make sure it doesn't have a "flap" obstructing the flow at higher speeds.

[Tom Kirkham]

F16N,

We have had the same results as you with electric water pumps. We just could not get enough water flow.

On the pulleys we build, we set the crank to pump pulley in a ratio of 1:1. This has worked very well on lots of FE engines. The problem we were facing was that most of the water pumps were being under driven and the engines would heat up while moving slow. At anything over 40 mph there were no problems. You have the opposite problem in that you are over driving your water pump by 35% (6.5/5.0)! I suspect that you are spinning your water pump too fast and cavitating the water pump impeller. When this happens the pump quits pumping.

Things that might help a cavitation problem... Run a bigger water pump pulley (or smaller crank pulley, but size it so your alternator still works), run a higher pressure radiator cap. Minimize any restrictions between the lower outlet on the radiator and the inlet to the water pump. An interesting experiment might be to remove the thermostat to see if you can stop the cavitation by removing this restriction...Something else you might want to try is to hook up a pressure gauge (an oil pressure gauge will work) to your block and see what the water pressure in you block is doing...(hint with a centrifugal pump pressure should go up with the square of speed...)
Put your electric pump in series (between the radiator and the water pump).

Hopefully this give you a little food for thought...

[Tom Kirkham]

I just remembered, I had a friend who had the same exact problem you had. His fan was wired backwards. The best way to check is to get a strip of paper and hang it by the fan and make sure the air is going the direction you want it moving.

[RICK LAKE]

f16n Sorry for all the info but this is what alot of guys have gone through with over heating problems. Pat also brings up a point, head gaskets, It is real easy to mount one unside down. They will go on either way and look fine. It takes a long time for the motor to over heat, about 1 hour. It will go into the 220f and stand there. How many miles are on this motor? Is it possible that it's had alot of hard abuse? Some guys had had problems with the motor running hot from the short hose going from the intake manifold back to the water pump. Too much hot coolant goes right back into the motor and not cycled through the radiator. It's a 1/2" or 5/8" hose. Block this off and see if the coolant is running more stable. The one thing that I do have on my motor is a bigger thermostat off a Dodge BB motor. The diameter is alot larger for flow. I had to custom it with a spacer to fit behind the tank. Do you have a small hole in the thermostat for air bubbles. It's a bleed hole. 1/8" with it mounted on the top. Your Edelbrock water pump has the plate for the impellor for high flow. You don't have to check this. See if you can make a coolant pressure tester and mount it on the windshield and go for a drive. This will show you who much pressure you system is running. I have a 14 psi cap on my car and the pressure when I check it didn't reach but 8-9 psi under hard driving. You will find the answer, it's always something simple. Just finding it is a pain in the @$$#%^&*&^%. Rick

[Maurice Johnson]

Rick is correct in his comment about a free spinning fan increasing the resistance to air flow. The flow substance in this case (air) performs the same as water, and it is a known fact that drag increases considerably from water flow over a free spinning propellor as against a "locked" one.
Sorry for the change in the reference medium, but I race sailboats as well.

[Bill Bess]

Ken is right on!

I had the same problem...too much heat, but here's my suggetions. 1) verify that the temp. gauge is accurate (use a infered gun to verify actual temp. when you are experiencing high temps.)..my gauge was defective. 2) install puller fan in lieu of pushers. 3) verify themostat..190 is good, 4) build a fan shroud with flapper vents, 5) burp the system ..make sure there is no air in system,. My FE now runs too cool now,and I live in the desert.

You might have a restriction in the system due to the fact that the motor runs cool while idling and gets hot when at speed. It should run cool at speed with no fans running.
Check all the hoses..perhaps a small piece of rubber is flapping down when the water pump is pushing under pressure at speed, and then relaxing at idle and letting the water flow, thus improving the cooling. Don't laugh..this has actually happened to me, it turned out to be a rubber sleeve that was closing off the water flow at high speed.

Anyway, just check the basics..gauge first and then a process of elimination...it's most likely a very simple problem.
Best Regards, Bill

[f16n]

Thanks for all the info. guys,I'll check everything out and reply later with the problem.

[sideoiler10]

I also have a Shell Vallley with a 427 sideoiler. Had the same problem. Curred it by shrouding the radiator instead of the fans. Such a shroud blocks all the spaces around the radiator where air flow can be forced around the radiator instead of through it. Made all the difference in the world. The two small pushers in front do not hurt air flow at all. I also replaced the rear siingle puller with a 3200 cfm zirgo unit with a manual switch. To be effective, the shroud must completely close off ALL the spaces aroujnd the radiator, incl. the space below and in front of it.

The aluminum shroud was cut and curved and looks sharp with the alum. radiator and fans.

[Dominik]

If the shrouding proves to be efficient, I recommend opening the top to allow some airflow through the engine bay. It helps cooling the firewall and engine. Engine surface radiates about 15% of total heat produced.

Dom

[Jamo]

I agree with Patrick...not the pusher fans. Mine are off at speed, and even with the slight drag of being coupled to the motors, it doesn't stop airflow. If pusher fans are having that much of an effect...then you have troubles elsewhere.

Tom's suggestions regarding the pulleys seems to fit your recent fitment changes the best. The water isn't moving the heat out of the block.

Assuming no air bubble in the system.