Customs Flattie runs hot

I have a 50 Shoebox,original V8,3 speed,having issues with it running hot. Over 200°.Have new pumps,thermostats,radiator rotted.placed a electric push fan.flushed engine.replaced with antifreeze. Thought I might have a gasket leak , it spits water out the right tailpipe at times,but oil is clean.Any suggestions would be greatly appreciated

 

Hi Krabz. Water out the exhaust could be blown head gasket, cracked head or just condensation. Run a compression test. Also what temp range stats are in the engine. Mine ran hotter with 160s so i went to 180s & it runs 180 to 185 all time without an electric fan. There are guys here much smarter than me & they will probably want more info. Post this on The Ford Barn too; lots of flatty guys there too.

 

Adjust your timing advance. That seems to be the solution in 90% of the “my flat head overheats” threads. Over time the springs get tired and they don’t do what they are supposed to

 

I know it’s a “long shot” and lots of work and it sounds like you have tried everything, but I am guessing there is an excess of “casting sand” in the pan rail of the water jacket. It means to remove both water pumps and make a “rake” out of a straightened out coat hanger. Make a 90 elbow and grind a sharp point and “drag” it along the pan rail inside of the water jacket going thru the big hole in the block. Make the sharp point dig into the hardened sand inside of the water jacket. The sharp point will eventually make the hardened sand into smaller pieces and keep digging and flushing with water until it is sand free. The Ford factory did not do a very good job removing the sand and after 60-70 years of running the engine the sand just keeps getting embedded deeper and deeper.When I build a new engine for myself or a customer, I actually push the bare block onto a piece of plywood with a lot of force to impact the block into the piece of plywood—-nothing is harmed when the block
is meets the plywood with a lot of force. If this is hard to understand,give me a phone and I will try to make it simpler than trying to writing what needs to be done.John in s.Texas 979-595-7324 cell.

 

Also check your advance. And see if it’s even working. Many old Ford distributors have a bad rotted diaphragm. Remove the cap. Remove the venture vacuum hose at the carburetor and give it a good ****.
By flushing the system….. exactly what did you use and how did you do it.
Yes a leak out of the exhaust is a symptom you want to investigate.

 

If you are running the stock LOM distributor with dual carburetors or one other than the stock 8BA/94, you have no functioning advance. Sure it will rev but...
Petejoe has had some luck with modifying the LOM distributor advance with dual 94s.

 

There is a chemical that you put in the coolant to detect the presence of exhaust gas(don't recall the name of it) that will detect cracks or leaking head gaskets. These are the most common causes of overheating. If this test is O K , start eliminating the less common problems. In my opinion, a rad shroud is a must. I also prefer a mechanical fan for better airflow. P M me if you wish more info.

 

Does your car have the panel above and down on the frame still installed? On '49 to '51 flathead Fords these are frequently removed for aesthetics and maintenance but are required for proper cooling. These two reasons along with the age of these engines are typically the main cause's for overheating.

This is the lower one frequently removed when changing water pumps and not re-installed or rusted away.

 

Put it on a light and time it. These engines can fool you by ear and just with a vacuum gauge. At a slow idle it should be pointer to dot.
I've found with the distributor out the engine will have a " tinny " sound but still make good vacuum. Adjusting the distributor to the proper position, it changes from the tinny sound to a low flathead rumble.

 

Go through the cooling system bucket list.

Timing/advance

coolant flow/water pumps/belts

airflow fan/belts....sheet metal and seals....You need to have that stuff but even with some of the sheet metal missing it should still cool. Really system in good condition should not have to have an auxiliary fan.

Thermostats are they 190s or 160s? Do they work?

Temperature gauge, is it accurate?

Exhaust? Do you have a restriction?

Oil....Oil plays a great role in cooling, maybe as much as the coolant itself. Flatheads are notorious for sludging up. The oil pick up may be blocked. Sludge may be all over the insides insulating the block, thus interfering with heat transfer. It's nasty and labor intensive to clean the sludge so it's often ignored. Another thing with oil is flow, if you are not running the proper restrictor for the oil filter line, you could be loosing pressure and volume to the oil filter.

You need to do a compression test.

Does the coolant smell of exhaust or gasoline?....This is not a good sign.

Mechanical stuff...water pumps hard to turn, generator hard to turn, fan hard to turn....Belts too tight.

 

If you're doing a compression test, try to do it with the engine at operating temperature.

If you find a su****iously low cylinder(s) you might want to do a cylinder leak-down test to determine the source of the leakage. When doing so, make sure to loosen the radiator cap or remove it and place a fender cover or moving pad over the top of the radiator. The reason for this is if you do have a blown head gasket or a crack into the cooling system, when you pressurize the cylinder it will attempt to force coolant out of the system.

Removing the cap and covering the top of the radiator may prevent damage to coolant hoses and heater core. It will also help keep you from getting sprayed with hot coolant.

 

Start cheap check the timing. Check for head gasket leak. Make sure the stats are opening, then tear it apart and clean all the casting sand out of it.