Overheating

Hello...

http://www.superford.org/?vID=4046

I just rebuilt my 351W in my 1983 Ford Bronco... I have a brand new 4-row core radiator - 160 Thermostat - 19" Flex-Fan (1/2 in 1/2 out of shroud) - new water pump...

When driving, my Bronco runs ok heat wise... (sometimes starts to heat up sometimes doesn't)

However, most of the time - AT STOPS - the temp rises very quickly... The temp can easily raise 35 - 50 degrees within 45 seconds... I can watch the gauge rise very quickly...

This to me points towards an air-flow problem... Because the truck runs pretty good temp wise while driving... Although for some reason... sometimes it takes several minutes of driving in order for the temp to start to go down, then several minutes more for it to finally reach normal operating temerature...

I dont know what else to do to fix my overheating problem... I have heard there are aftermarket solutions for heating problems... but, have not been able to find any of them...

Any help or suggestions would certainly be appreciated...[url]

yo Eric,
Under normal high rpm conditions, ie: highway speeds, the ram effect should be enough to cool the radiator. The fan doesn't need to pull air under these conditions. The major problem with flex fans occurs when they are used on vehicles that are operated at high rpms, but at low speeds. I have seen 4 wheel drive pickups overheat when driven off-road because the owner had installed a flex fan. If your engine overheats at highway speeds with a flex fan you have other problems (radiator partially blocked inernally or externally, retarded timing, F/A mixture too lean).
Is it an alum fan blase or ss? Jury is out on these or using electric fans (see my web site under technical for some other Bronco owner's articles on electric fans; such as Froggmann(site is down right now, and Gremlins twin fan installation) .

160 degree thermostat is too low. You should be running a 180 degree at minimum. Because of the low setting, the coolant in the radiator isn't getting an opportunity to cool so the pump is recycling still warm coolant. Also, if you have removed your fan shroud, that will also decrease cooling ability at low/no speed. Try these ideas before you spend too much cash on high speed fans, pumps, etc. You already have a four core radiator so you should be running cool with these inexpensive changes. Hope all works well.