Anybody else having problems cooling the 502/502? I seem to have air trapped and can't get water to circulate. I don't have a thermostat, just a restrictor, the idle temps are 150 engine, 125 inlet and outlet hoses, 90 at each tank on the radiator. The water just dosn't flow, i've had 2 other pumps on it and ready to hook in an electric pump to force water thru the mechanical pump. The idle temp is in the shop, on the highway it continues to rise and will overheat if doing traffic lights, on the road it is very slow to recover. I have dual fans on the radiator with a fabricated shroud, the engine bay is open (no inner fenders) but no vents in hood etc; i have removed the grille to let in all possible air. I am thinking that if the radiator temp at outlet is 90 then the lower hose should be 90 as well, but it is the same as the upper hose and the inlet side of the radiator should be the same as the upper hose (125deg) and that is what makes me think that the water isn't circulating. I have the fans 'on' with the key, again no thermostat. Thanks, oj
Good question and good point squirrel, yes the pump is a reverse rotation (i have tried another reverse rotation and a regular rotation pump; i have run a seperate belt out to a drill and spun each of these pumps both backwards and forwards, no water flow but noticed a dip in the level, so the pumps did something). I don't know how to do captions on the pics, the tank on top of the radiator is to raise the coolant level/filler to above the engine; the heater is highest point and i have bled those lines. There are 2 - 12" fans that run continuous on the key, i have milled slots in the shroud to let more air thru while it is on the road.
Can you disconnect the top hose either at the thermostat housing or at the tank and fire the motor (or just spin the pump) to see if water pumps out? It should gush out.
It looks like the shroud is blocking a good deal of the radiator, especially in the lower left and upper right corners and putting slots it isn't helping the fans pull any more air either. Also, do you know what the CFM ratings are? I would probably build a new shroud that's a little deeper, if possible and make sure the fans are up to the task. Then put flaps in the corners to let pressure escape at speed, yet allowing the fans to work effectively in traffic.
Now that I looked at it a second time, it seems the fans are centered, not diagonal, but mounting them in that manner would better allow for the "flaps".
I see heater hoses. If you want to verify pump flow you can pull the heater hose that is sourced from the manifold from the heater core. Plug the heater core so you don't suck air through it and run the hose from the manifold into a bucket. You should be able to fill up a 5 gallon bucket with the heater hose line in about 2-3 minutes, be careful not to run this too long, just verify. Best to do this on a cold engine. -------------------------------------------------------------------------- Just wanted to show you my set up. Just did the HAMB Drags and back with the AC on all the way and had no cooling issues. My system is similar to yours with the low radiator situation. I run a 427 with a Vintage Air Front Runner set up that does away with the bypass. This caused one serious issue, waterhammering. The steam pockets would build up and slam the thermostat around. Drilling it out did not help. My other issue was the radiator itself. I have a Ron Davis double pass and the neck was mounted on the left side tank at an angle. As steam would build up it would push out coolant. Over a short period of time this would drop the coolant level enough to cause problems. This is my solution, a de-gass bottle or surge tank. If you notice there are two hoses feeding it. the #4 line bleeds any steam built up in the radiator and the #6 hose is the direct bypass for the pump. If you look closely you might be able to see the heater hose line is split and feeds into the tank. This way the bypass circuit is completed and gives a place for the heater to dump back into without adding more fittings to my tank or putting in Tees. I could draw out a diagram later if you need help understanding this concept. Cooling wise I have a pair of Spal fans, a 16" 2400+ CFM fan with a variable speed controler and a 14" 1900+ CFM fan on the Ron Davis 19"X31"X3" radiator. Sitting in traffic I still see temps getting up to 210 but never had a boil over or any other signs of overheating since I have done this. You have to remember these aftermarket aluminum radiators are really dense. High fin counts and louvered fins make it difficult to draw air through at low speeds compared to OEM or brass/copper equivalents. That's what it takes for me to keep this thing cool out here in the desert with little or no humidity. In Texas, Oklahoma and Missouri This thing ran on the thermostat constantly. The humidity really helps with heat transfer in my case.
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