Posted by Keith in Washington [108.162.246.30] on Tuesday, May 24, 2016 at 10:38:37 :
In Reply to: Overheating ( Maybe) in 360 posted by Jim in Litchfield Park [162.158.141.36] on Monday, May 23, 2016 at 21:12:42 :
I would look very carefully at the fan and air flow. There is not much room for air to move through the engine compartment. My WC53 with a V8 would constantly overheat at low speeds or sitting still but was ok above 35 MPH. I ended up redesigning the fan shroud and adjusting the position of the fan to place it correctly in relation to the shroud. I am using a flex fan mounted on the water pump shaft (I hate radiator mounted pusher or puller fans). I would suggest a fan that runs all the time. A temp controlled fan starts to run when when the engine is already hot and has an uphill battle to cool it down.
Here is what I found out in my research and trials.
1) The fan shroud needs to cover the entire radiator. If it does not your only getting air flow through a small part of the radiator. (This is why I dislike radiator mounted fans)
2) The hole in the fan shroud should be centered on the fan and have a max of 1/2" clearance around the fan. It helps to have a lip on the engine side of the fan hole in the shroud for stiffness and air flow. You can a just the holes position with a piece sheet metal. I simply pop rivited a piece of sheet metal with a correct hole to the original shroud. I did not have to cut up the original shroud at all.
3) The fan needs to be 1/3 of its thickness into the fan shroud. This has been proven to be ideal for air flow as there is minimal air disturbance at the tips of the blades. I adjusted the fan's position with spacers on the water pump.
4) I use a flex fan as it has max pull at low RPM were it is needed then flattens out at higher RPMs. At higher speeds the air flow is enhanced by the speed of the truck.
My problem was similar to yours. In cooler weather here in Seattle I rarely saw any overheating. It showed up when I was in Reno NV for Hot August Nights. It's temp would very quickly shoot up to 230 or above when I was at low speeds (think parade) but would cool down to normal at 45 MPH or higher. After a couple of years of fighting the problem I can now take the truck in to a parade in Reno with the air temp above 90 degrees and I may see the temp gauge max out at about 200 degrees.
As you know space is very tight with a V8, especially between the fan and engine. It took quite a bit of thinking to figure out how to do what I needed in that small space. The original PW shroud is very flat which really helps but I am still very tight to the power steering pump (no I don't have PS but I use it for the hydroboost brakes)
Let me know if I can help.
Follow Ups: