I'm Loosing my Cool, Litterally!

I would pull the pump before you go chasing your tail any longer. I have also had this issue before. And as stated the impeller on one was all rotted away. On the other it had just fallen off the shaft.

 

The electric fans are a band-aid fix. The shroud should be fine, and as you also said, was fine when the car was new. It's a circulation issue. If the pump is fine after an inspection then the inside of the block or heads may have excessive amounts of sediment reducing capacity. Sure it's a mess, but you may need to make a bigger one and flush the block. Simple and nearly free. I also think a clutch fan would be more effective for your combination vs the twin electrics. The electrics will now block airflow unless they're running.

 

Have you tested one of those combustion leak things, could be a blown headgasket or a cracked head.
Thats how i solved my overheating problems after doing all of the above, turned out to be the headgasket.

 

I agree that the shroud should be fine as is, and that it really shouldn't need the electric fan.
Perhaps it is the water pump, but, it cools fine 95% of the time, only if I get in traffic (more then a red light) does it start to creep up in temp. It seems to me that if the water pump impeller was broken or corroded it would heat up all the time? I don't really know, and like I said, adding the fan and sealing the shroud is free so if that doesn't work. The pump is next.

 

Hey man, I striped the speedo in that thing!

 

Yes you did! Didn't you do the striping on the outside too? Or just the dash?

 

You can make a rough check on whether vacuum advance is working or not by pulling the distributor vacuum line and seeing if the engine's idle speed slows down - it should.

Connecting the distributor vacuum line will cause the engine to speed up.

Make sure the vacuum line is connected to full time manifold vacuum.

Ported vacuum almost always causes overheating.
No surprise there, GM developed ported timing just for that purpose.

Hot engines do better in the smog dept, but are tough on the checkbook....

 

I had a Buick that would do the same thing. Checked the vacuum advance, it wasn't working, replaced it, and it helped, but would still heat up at a stop light. The final solution was replacing the timing chain and sprockets, a stretched chain was allowing the cam to retard enough at idle to make it heat up.

 

If you've got a decent radiator cap (say 16 pounds) you can run the temps all the way up to 250 degrees and it won't hurt anything...UNLESS you keep it at that temp for a long time...a few minutes won't hurt...IF it doesn't dump fluid out the overflow, it's not that hot...

Best thing you can do is have someone test the water temps with a laser type gun, or insert a thermometer into the water when it's hot (rad shops can do this for you)...it could be that your guage is the culprit...had this experience too...my '40 Stude, with small blok 400", constantly read 220 degrees...I was panicked, had the water tested at a rad shop, thermometer read 185 degrees...guage was off...!!!

I've had the same problem with creeping temps as you...I have a '57 Chevy with a stock crate 350"/4-speed...was always overheating...bought an aluminum 4 row rad, changed to a five bladed 18" fan (up from a 14"), built a shroud that covered the whole rad (and not allowed any air to get past radiator), put in a new thermostat and a new water pump...solved the whole problem...runs at 170 on the hiway...seldom gets over 200 in traffic of any kind.

R-

 

If your car ran ok before you put in the aluminum radiator, the fan and shroud should be fine. The gaps others are pointing out are stock from the factory, so i doubt after 49 years, they would all of a sudden cause a problem. I would suggest measuring the depth of the radiator to the cross member and the depth of the stock one. If it sits a little deeper, then the fan will sit too far in the fan shroud (since the engine is in the same spot) and cause wind-tumble inside the shroud, slowing the flow of air over the fins, which may only be realized when the car is sitting still and not have air flow from motion to compensate. If this is the case, just shorten the shroud accordingly.

 

I have been down this road with a 57 chev. Tried electric fans/rad/shroud/ including a new motor. It was the same. Came down to a improper sending unit for Smiths gauge. It never boiled over and that should have been the clue. Measure the temp of water in the rad to make sure gauge is correct.

 

Roger's comment on using an external temperature gauge is a good one.

You can buy candy thermometers at any cooking store*.
Both in the glass tube style and the BBQ style with probe and circular mechanical gauge.

They work great in radiator coolant.
Best to pull the cap, then start the engine and bring it up to temp.


*What the hell is he doing in a cooking store you ask?

Buying cooking stuff.
Almost better'n walking through the Proto tool truck.
They got stuff, way cool stuff.

I can cook you up a pan fried Ribeye Steak inside the wood fired BBQ that's like nothing you ever ate.

Among other good things.

How many guys do you know who have their own cookbook collection....

 

I do have a laser thermometer I have not used it on this car to check the gauge. I also have a fance digital thermometer my Dad got me (he's a bit of a cooking nut himself) for the bbq that I could use in the water.

When I got the car with the original radiator it ran HOT all the time, which is why I bought the aluminum one. I've been told the fan is in the right spot, just inside the shroud with a bit outside of it.

I'll have to get the laser thermo. out to check also. The main reason I haven't is because it reads in the correct temp while driving then creeps up, and actually read correctly when I switched from a 180 to a 160 tstat (meaning it went from 180-190 to 160-170 while driving.

 

Its summertime, so maybe drain out the coolant and run straight water with water wetter and a can of water pump lubricant. Coolant may help raise the boiling point, but it does not dissipate heat, so essentially you have half as much heat dissipation capacity running 50/50. Just pour your current mix in bottles and pour it in when the weather is cold and you don't need to worry about cooling as much. Out here, I never run antifreeze/coolant and I can sit in downtown freeway traffic in in the middle of summer a 50 Ford with a flattie and stock system and never get about 190. (the only time it is below 32 degrees is when i spend too much time with the freezer door open)

 

But that's another bandaid... it worked fine with 50-50 before; what changed?

 

Something not mentioned but very important here.

The new aluminum radiator is most likely the culprit and here is why. You stated that the temps come down as soon as you start to move but climb back up when you sit at a long light. That right there tells the entire story. It's airflow.

The original radiator most likely had a fin count of 7 to 10 fins per inch. Also the tubes were most likely farther apart. The new radiator in all reality has a higher fin count, somewhere in the 14-16 FPI range and the tubes are closer together. This makes for a much denser radiator to pull air through. With a stock fan that had a low pitch angle that made it quiet, but also had issues with cooling a stock set up is definitely going to have issues with a radiator that is twice as restrictive.

Grab a fan and clutch off an 80s Camaro with V-belts, not serpentine (serpentine is reversed direction!) and your problem should be solved.

 

Have you ever flushed the block out ? There can be rust and crud blocking the water passages .

Check the temp sending unit and the temp gage .

Check the upper and lower radiator hoses on the inside to see if it is separating and stopping the flow .

I hate to say this but remove the water pump and check to see if the fins are turning or are just working sometimes . I had a Dodge that had the same problem and the fins on the back of the water pump was not turning all the time .

What size radiator cap do you have and what style cap .

I agree with a few here that the radiator and fan shroud are your problem and the electric fan fill not fix the problem !

 

stock pulleys? or aftermarket? hi-flow water pump?

 

I haven't read all the responces but try a smaller water pump pulley,,it cured my problem after I tried everything else! HRP

 

Not an expert but it sounds like the coolant isn't circulating fast enough at idle. Smaller pully could help. Where is the sender located, engine block, cylinder head, intake manifold. I'm asking because 215 isn't close to boilling point. My electric doesn't come on until 220. It cools the car off to 180 - 190. My car runs 190 all day long, never over heated yet. Drive in traffic Street Rods Nationals Ky no problems.
I think you should let it idle in front of the garage with no circulation at all. See what happens...
If it starts to get real hot shut it down and try something else.

P.S. Brand new cars have shitter cooling systems than most HotRods and the electric fans don't come on until 220...

 

Again for emphasis, air flow.

Smaller water pump pulleys may speed the fan and the pump by a few percent but... when dealing with an inefficient fan the small increase in fan RPM will not be enough to solve the problem. A new(er) and more efficient fan will.

 

Wow. Whole lotta wrongness going on here.

You've accepted that it's an airflow issue. I gotta agree with that based on the fact it likes moving in clean air.

However, you're skipping about 30 years of fan technology. I disagree with the statement that the stock fan is good enough. Completely disagree. Get a real fan, with a clutch. They're cheap. Look for anything chevy rwd in the junkyard from the 70s/80s. It'll move twice the air your stock fan does.

As soon as you install the electric fan you're gonna discover the charging system is insufficient to run the fan in traffic. You'll need an alternator off a car from the era of electric fans. The alternator evolution is not coincidental. This is the voice of experience saying this.

Just stop the snowballing-out-of-control chain right now. Grab a $25 clutch fan and just be done with it. Your stock fan is a piece of crap. Admit it.

good luck

 

Yes, it is an air flow issue but at the end of the day 215 degrees is not hot. I agree that a never fan should fix the problem. Keep it simple but at no means is the car even close to over heating and 215. If the car never exceeds 230 the original fan is fine.
That is why I mentioned to park the car against the garage door,
(no airflow) let it idle and see what happens.

 

So the wagon has been running hot since you got it and only since installing the AL rad is the temp "normal" at speed. I'll throw my 2 cents in....warped head.

 

You say that the car ran hot with the old rad.Was it clogged when you removed it?It may be that replacing it has partially cured the running hot issue,and that the block may still be clogged up with sludge.
If I remember correctly,the S.B.C. has a pipe threaded plug in the lower part of the water gallery on both sides of the block about half way along,just above the oil pan rail.
If you remove the plugs(engine cold),and nothing comes out,you have a blockage and need to flush the block.
I had a Camaro a few years back that would over heat in traffic.A good flush out of the rad and block cured it.
Good luck,regards ,Mark.

 

maybe, could be water flow also.....

 

I seriously doubt it.

Want to know why?

Because he did not state there was a problem while at steady state low RPM driving. This is my 25+ years of experience dealing with real heat here in Phoenix, AZ on daily driven cars, low water flow issues will manifest themselves while driving at steady state low rpm cruising. Whether it's a collapsing lower hose, bad water pump, cavitation or mismatched pulleys the car will run hot in high gear at 45 MPH.

You would be shocked at just how much coolant a piss-poor cheapo water pump can move even spinning at 500 RPM.

 

just the dash

 

How about a 7 blade steel OEM fan with a clutch? Back in '60 those 283's
ran cool enough at the lights that they didn't require anything very elaborate.

 

my dodge is having very similar problems... just had the radiator flushed and a couple holes filled.. ever since been running high temps. im convinced its water flow problems... possible trash in pump or somewhere else. my mechanic is checking it today...