I may have asked a question similar to this a while ago, but I forgot if anyone said anything.

My 73 has a belt driven fan of course... it's a big 4 blade steel windmill that probably weighs 15 lbs, haha.

About a year ago during the summer I was having some trouble with overheating while idling in traffic. It would cool down if I put the heat on, dropped it in neutral and reved it up a little to get the fan and coolant moving faster... but it shouldn't get that hot in the first place.

the old radiator was in pretty rough shape so last winter when I did all that painting under the hood, I ended up buying a brand new radiator from GM, as well as a re-manufactured water pump. Now that the radiator and water pump are new, sometimes it still gets hotter than I'd like it to. (I don’t have a gauge but when I see that idiot light start flashing… that’s too hot!

Ultimately I want to have only an electric fan(s) so that they will run only when needed, and I can get more air moving under the hood when sitting in traffic on a hot day. Also I wouldn’t mind getting rid of that big ol’ belt driven fan. I don't have AC and there is no shroud on the radiator, (it never had one) so this shouldn't be too hard. Space is NOT a problem.

Are there kits out there that have everything you need to do this?
I want it to run independently because I don't want to have to be switching it on and off. I’ve been looking around and I see electric fans everywhere but nothing to control them. (automatically switch on and off when the temp rises) I guess the ones I see on the shelf in parts stores are meant to replace fans in cars that are already set up for it.

Also (stroker you might know about this) I was reading something about the "emission control" features from 73 and it said they used "higher temperature thermostats" isn't it a little tougher on the engine to be constantly running at a high temp? Think I should get a different thermostat? The one that’s in there now is the original.

I’m open for suggestions!

"Think I should get a different thermostat? The one that’s in there now is the original."


Dont you think you should change your thermostat???

Not because it might be causing the problem but because it is like
30 years olds

haha, this is true..... but most of the engine's parts are 30 years old.... If I just started replacing things simply because they're old I might as well build a whole new engine!

I had an 84' caprice with a 305 in it... I started having intermittent overheating problems with it, and we replaced the thermostat... At the parts store, they had 3 different temperature thermostats to choose from! Each is designed for a different purpose I guess, and different climates too. It gets very cold here in the winter time, and I always had LOADS of heat from the vents to keep me toasty... But after the swap, I really did notice a difference in the amount of heat I got, since it was a lower temp thermostat, I got less heat...

If you've ever seen a thermostat before, they are quite small and I would assume after 30 years, there might be a lot of calcium and buildup on it, maybe even restricting flow, and causing problems. They are VERY cheap to buy, and easy to replace... I would give it a try!

The electric fan idea is a good one too... I've never heard of a kit to do this, but why dont you rob the control out of a small simple car at the junk yard? Dont a lot of hot rodders use electric fans now? I wonder how they make thiers work....

Hey, you might want to check this out:
http://www.jegs.com/cgi-bin/ncommerce3/ ... rmenbr=361
Looks like it would do the job, can control up to two electric fans (2 fans requires the 30 amp relay).

TOC Admin
Brando

looks good... I found more stuff here too http://www.alamomotorsports.com/pmc/Cat_page19.html
I wonder what the "optimal" temp for my engine is. I only use it during the warmer months, so maybe I should look for a different T-stat

ok delta..heres my thought on this....there is NO reason your car should be getting hot enough to trip the idiot light, thats NOT good. The FIRST thing i would do is have the cooling system flushed and replace the thermostat. I'm guessing the main part of the reason that youre having overheating problems is due to the lack of a fan shroud. The fan shroud helps to cause suction thru the fan, therefore helping to bring cooler air into the radiator and therefore, helping to keep the engine cool. Your car SHOULD have at least a 3 core radiator from the factory...an A/C car would have a 4 core. To theoretically cool your engine using only electric fans you'd have to run a minimum of 2 16" fans. You have to remember that youre pulling a car around that weighs at least 4200 lbs, if not more. My suggestion would be to change the thermostat, find a stock radiator shroud and install it, and your problems should be gone. My vista runs a 4 core with the stock cooling system, and never gives me heat problems. My cutlass, with the 12:1 stroker motor, 3500 stall, and 3.73s, on the last car cruise i went on, went no higher than 210 degrees sitting in traffic, and we're talking a high performance race engine running over 600 hp. If you run mostly in the summer months, you could go to a 160 degree t-stat, otherwise i'd stick with either the 180 degree or 195 degree. If you really want to do the electric fans, you can use a temp sender from a later GM car and a relay to trip the fans on and off, but i'd use the old fashioned method of K.I.S.S, or Keep It Simple,Stupid...and just stick with the original design and setup. As i said, i suspect that the lack of a shroud is the major part of your cooling problem.

Stroker I agree with you completely... but I know for a fact that the car came without a shroud brand new, strange huh :? I think that if it had A/C or factory heavy duty cooling then it came with one, but mine didn't.

as for flushing the system, I've done that many MANY times since I started fixing up the car and now the fluid stays clean as could be, but I still flush it at least once a year

the radiator is a 3 core and is less than a year old (it's definitely not clogged up or anything like that)

so I will get a 160 degree thermostat and decide if I want to just try to find a shroud, or wire up a couple electric fans.

Thanks for your input

by the way... are there any pros / cons between the 160 and 180 degree T-stat? (besides the difference in heat from the heater) I've heard people argue that 160 is too cool... but they are most likely talking about fuel injected engines unlike mine. How cool is too cool in my case?

any thoughts?

heres another point to ponder...IF you decide to go the electric fan route, it might be a good idea to convert to the internally regulated SI GM alternator, reason being that the external regulated alternator tends to not charge as well at idle, and if youre running electric fans, especially dual fans, the amperage draw of the fans may overcome the charging capability of the alternator at lower RPMS, then youre stuck with a charging system gremlin...just a thought. To go back to the electric fan theory, you can go the prebuilt route and adjustability that the aftermarket temp controls provide, or you can wire the fans thru a relay, add a coolant temp sensor from a newer F body car ( stock it trips and grounds out at around 210-220 degrees ), and run the ground from the relay to the temp sensor, if youre going to use an electric fan as an auxiliary.In this configuration, when the temp sensor hits the designated temperature, it will make contact to ground, grounding the relay and tripping the electric fan.

Today I went shopping, got two 14" electric fans, and an adjustable relay to regulate them. 14" fans were the largest I could get, because my radiator is about 28" wide, so they fit quite nicely. These fans definitely move alot more air than my previous setup did. I have a 180* T-stat, so I set the fans to kick on at about 190*

http://img234.imageshack.us/img234/4949/p10100028ht.jpg

http://img213.imageshack.us/img213/7892/p10100051ki.jpg

Now the only question is... can my stock alternator keep up on a hot day? I think I'll keep my portable battery charger with me for a while just in case

sweet...looks good!

Yea...too bad I sold my high amp alternator that would of fit in your car

TOC Admin
Brando

I thought of that too, but if this one doesn't work out I'll probably look into stroker's suggestion:

yes, the alternator I had was internally regulated...10-SI.

TOC Admin
Brando

I think it'll be ok, I let it idle for a quite a while with the fans running and the high beams on and the battery wasn't noticably drained afterwords... I'm still going to carry my charger though. The fans draw a total of 23 amps (11.5 each)