Well, one of the shops I keep on good relations with finally got in three solid 7-bladed radiator fans. These are the ones that look like the clutch fans, but bolt right up to the pulleys. They run all the time. That may solve the problem I have which is that the car tends to overheat while idling in gear. Keeping my fingers crossed!

Jerry

good luck on this jerry! have you tried the mods from poerformance years to increase the flow of the water pump? if it doesnt work there are other ways to increase flow or coolant abilities. a product called water wetter can decrease temps by 5-10 degrees and does so in most cases!

Just out of curiousity...what radiator cap are you using? According to one of the local radiator experts (40 yrs worth), he says that 9 times out of 10 overheating problems are related to the wrong cap. Closed vs open systems, incorrect lbs, etc...

I believe your expert was talking about newer cars with open systems(catch can). Ours are closed.

Uhm...I think thats backwards, isn't it? Prior to the 70s everything was open, right? His suggestion to me on mine was to setup a resevoir (closed system) vs allowing it to exit to the street (open).

http://www.familycar.com/Classroom/CoolingSystem.htm

"Prior to the '70s, the cap would release this extra pressure to the pavement. Since then, a system was added to capture any released fluid and store it temporarily in a reserve tank. This fluid would then return to the cooling system after the engine cooled down. This is what is called a closed cooling system."

So maybe the question is, does he have a resevoir setup?

Technically, you are right. What I meant by open was a 'give and take' between the radiator and a catch can. Those systems interact to help cooling. When our systems are working right there shouldn't be enough pressure to open the cap.

Yep...

The old guy at the radiator shop was talking about the same kind of thing.

His point was that many times the wrong cap was being used, therefore allowing the pressure and fluid to escape too easily, and since there was no return system in place, the radiator would suck up air to return back to the radiator, and over time, presto, overheating from lack of radiator fluid.

His solution was to use the correct cap for the car, and go to the newer system of a resevoir to prevent air being sucked back in.

Funny thing. I talked to an old guy at a radiator shop and he said that our systems build too much pressure. He showed me how to cut a tiny slit in the rubber seal of the cap to alleviate the pressure. I'll stick with the stock system. It works for a stock car.

Sorry it took so long to get back to this (computer had a snafu). Andy, I forgot to mention that we're planning on pulling the water pump to do the mods, but I'm hopeful that the new fan will help (or cure) my low idle overheating problem. As for a radiator cap, I've got the Rodney Red radiator on the car with the cap that came with it. I've also got an Moroso overflow bottle hooked up to the radiator which actually has a return pipe on it. So far, I've never put more than a few drops into it so I don't really know if it returns the fluid to the radiator or not.

My overheating is an airflow problem, not a radiator problem as I have no problems once the car is moving or in park (higher idle) for that matter. The only overheating that occurs is when the car is idling in drive. Of course, once the temp comes up, it doesn't want to go down.

Once I get the fan mounted, I'll let you all know if it works or not!

Jerry

Good info. I've got one of those solid fans on my vert. It works better than the clutch fan I had on it. Moves a lot of air. If you have a quiet car you can really hear it.

quiet car, ha!ha!ha! It's a 462 with Thrush turbos.

Jerry

Jim, what do you mean "solid fan"? I switched to a 7 blade from an incorrect 5, and it seems to be worse by a tad? I don't overheat, but I dump when the engine is turned off on a hot day. It's not too much dumping but it's more than I care to clean up off the garage floor.

I wonder what's up.

Sounds like you have an incorrect PSI rad cap. A correct cap is 14-17 PSI.

'Solid' meaning not a flex fan and not a clutch fan. A solid steel fan.

You should probably install an overflow bottle, or better yet, a recovery system. A generic recovery system can be bought at Pep Boys, NAPA, etc. for under $15. The only other thing you'll need is the correct radiator cap for a closed cooling system (post-1971), and nearly every auto parts store carries those.

Sometimes this is a symptom of an air pocket. When you shut the car off, coolant is allowed into the area the air pocket was and turns to steam causing high pressure dump.

I had the cap tested and it's good. At what temp would the dummy light come on?

dunno. the pressure should be in the 14-17 psi range. if its not then you have the wrong cap. the dummy light should come one around 210 i think but dont quote me on it. normal light these day come one in the 220-230 range!