VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1933-1936 Overheating and a pusher fan

Those are what is known as flex fans and probably still available at most parts stores,I had one on a 72 AMX many years ago and I could not sit in traffic very long or it would overheat. Replaced it with a stock four blade fan and it did not overheat any more,how much room does a 36 have between the fan and radiator as my 37 only has 1/4 inch but I have a buinch of different years parts on it.

I am Phil Lipton, and here is my experience. I have a 1935 Std coupe with the 207 engine. I have owned the car almost 40 years. It has always had a tendency to run hot on 90 deg days, especially when in a
parade. I replaced the cyl head w/ a NOS '36 head, checked all the block water passages, probed everywhere in the water jacket and found no evidence of sludge or rust and scale. I rebuilt the water pump using
a NOS impeller, checked the head to be sure it was not warped, and put
it back on w/ a new copper head gasket, carefully torquing it to specs
in proper sequence. Nothing helped. About a year ago, on a 90+ deg day
I backed the car half out of the garage and let it idle while I watched the temp gauge, and soon went to 200 deg. I had a pedestal
fan in the garage and placed it about two feet in front of the car, and the temp cooled right down to 180. This convinced me it was an air-flow problem! I forgot to mention I also had the radiator re-
cored w/ a high efficiency core before this test. I made a recovery
system which seemed to help a little. I discovered it ran cooler on
plain water than w/ 50/50 permanent anti freeze. I tried updating
the fan blades, but there is not enough clearance at the radiator to
permit this.My next step,reluctantly, is to install a 'pusher' electric fan. Mormal driving, when the car in motion and there is air flow through the radiator, temp stays around 180 deg. If I get
caught up in traffic, or stopped at a traffic light, temp climbs to
200, and it takes a while for it to come down. It has never boiled,
but ever since I installed the accessory temp gauge I seem to drive with one eye on it. That's where I am as of now! Hope this helps,
Phil Lipton

Tests show they run cooler with plain water...Just don't leave it out in the cold...They used to have this milky white additive to prevent rust...Can't recall the name....Sorry

I on occasion I still run across old mountain road sign's that say..."Radiator Water Only"...Tempted to remove one...lol Heck, I drink from them...

Those aluminum fans did not work as they drew less air than stock. Were meant to increase horsepower for racing thru less drag, contrary to what we wanted them to do.

mike

I have a 6 blade flex fan on my 207. Early last year I went through my entire system. The culprit was blocked water jackets in my cylinder head. And a radiator pushing 30% of it's capacity.
Prior to that I removed my 4 blade and replaced it with a 6 blade flex. I opted to keep it there during re-assembly.
The problem was the hub of the old vs new were opposite in that if you lay them flat on a table, the old fan blades are pitched forward of the hub. So the flex fan blades did not clear the generator pulley. Having several old pumps I cut the front of one off using it as a spacer to clear the generator. Doing this brings the fan very close to the radiator. So the mod requires the radiator to be removed first. The outcome was great. Our low RPM engines won't cause the blades to flatten like the race engines they were designed to be installed in. (My opinion)
With the waterpump out check the baffle behind it, in the block. Mine was actually missing when I bought the car.
A satin black finish on the flex fan and very few notice the mod.

My '36 will boil over only if the nose is down like stopping on an incline at the bottom of a hill at a robot for example. After a run I always park on the level or with the nose up. The engine bay is small and there is much heat to dissipate. My 41 Olds suffers also from a very hot engine bay after a run. I think Harley Earl didn't leave much room for the engine after his tasteful styling exercises.

Simple test performed at idle.

With motor running and a stock 4 or preferredly 6 blade fan , place a light cloth 2 x 2 ft sq in front of the radiator starting at 1 foot away and watch what happens.

Then do the same test with the aluminum flex fan and watch what happens.

And the result is ?????? which fan system produced the most amount of air draw thru the radiator ?

mike lynch..........

I have the same overheating problem with my '33 Master and think the electric fan would solve the problem. When you are driving at 50 mph for awhile and then have to sit at a stoplight for awhile the residual engine heat and the minimal air flow over the radiator results in coolant temperature rise especially on a hot day. The only problem I have is there is not enough space between the radiator and the grill. I haven't found a flatter fan yet. Another trick used to be spraying the front of the radiator with a fine spray of water. I haven't found a suitable 6v pump yet. I guess you could just use a garden sprayer and have your mechanic keep pumping?

When sitting idling up at Lake Tahoe this past August for 20 minutes in traffic (modern car) I was thinking overheating is going to be a problem at the 2016 event at Tahoe. I mentioned this to the powers to be with no satisfaction (minds made up).

Any of the 1933---1936 Chevrolets can easily have a pusher fan electric between the radiator core face and behind the grill mesh.

Will require the removal of the rad shell to mount the pusher fan.

Other point........200 F degrees is not boiling, 212 is.

The boiling point can be increased with the addition of a radiator pressurized system. Block off top by welding soldering a plate over it. Take new filler neck that accepts a pressure cap. For each pound of cap pressure, boiling point raises 3 degrees......, 10 pound cap = 30 degrees boiling point is raised to 242.

Too bad the stock water pump and fan is so close to rad, the simple addition of a 6-7 blade fan is the least costly option.

mike.......