Overheating

[lee]

I need a little help. This is a freshly rebuilt 302 all new cooling system. As you can see from pics it is running hot and this is just after 10 miles. Any suggestions would be appreciated.
Thanks Lee

 

[pfreen]

Assuming your cooling system is properly filled and purged of air and you have coolant flow, your ignition timing is not way retarded, (I noticed the vacuum advance is disconnected), and the fan is blowing, then it is likely to be the thermostat or a bad radiator.
I am not sure if it is possible on small block Fords, but I have seen thermostats installed backwards, which don't work and never open.

 

[Austin Healer]

it's also possible to install the head gaskets backwards... they are clearly marked "FRONT"... they'll fit either way, but the engine will overheat if they are installed backwards... as this is a fresh rebuild, that's something that is obviously possible. I also don't think the expansion tank is large enough, but that's pretty minor.

usual checks are thermostat... (pointy end goes toward the radiator!!) should be 160 degrees, timing should be 10 degrees BTDC at idle, vac. plugged. make sure you are not running overly lean. tune with a vacuum gauge. a little rich is better than lean...

if the car is on the move, the fan is completely irrelevant. the air flowing through the radiator will provide all of the cooling.

make sure at idle a piece of paper will get sucked to the front of the radiator. if it doesn't, the fan's on backwards..

 

[lee]

it's also possible to install the head gaskets backwards... they are clearly marked "FRONT"... they'll fit either way, but the engine will overheat if they are installed backwards... as this is a fresh rebuild, that's something that is obviously possible. I also don't think the expansion tank is large enough, but that's pretty minor.

usual checks are thermostat... (pointy end goes toward the radiator!!) should be 160 degrees, timing should be 10 degrees BTDC at idle, vac. plugged. make sure you are not running overly lean. tune with a vacuum gauge. a little rich is better than lean...

if the car is on the move, the fan is completely irrelevant. the air flowing through the radiator will provide all of the cooling.

make sure at idle a piece of paper will get sucked to the front of the radiator. if it doesn't, the fan's on backwards..

thanks for the info

 

[lee]

Assuming your cooling system is properly filled and purged of air and you have coolant flow, your ignition timing is not way retarded, (I noticed the vacuum advance is disconnected), and the fan is blowing, then it is likely to be the thermostat or a bad radiator.
I am not sure if it is possible on small block Fords, but I have seen thermostats installed backwards, which don't work and never open.

thank you

 

[1949FL]

Lee:
You have received several great suggestions for the responders so far. So, if the ballast tank was not warm after 10 miles of driving, I would suggest the thermostat was installed backwards, although these days it might also be defective. Does the overflow hose drain below the car on the right side? It appears the radiator fluid is coming out the passenger side of the vehicle. I recommend you also find out why the fluid is leaking on the opposite side from the ballast tank and overflow hose. Make sure you have a 13 Lb cap for your car, unless you have an early Tiger. Tighten all your hose connections or at least check for leaks. If you built the engine and remember the head gasket placement you can answer the questions about whether or not they are backwards. It looks like you have a fan installed, is it the original stock fan blade or do you have a flex fan blade. A flex fan will cool your engine better, also check to be sure your water pump is rotating, i.e., no loose fan belt.
Cooling fluid under the car w/o steam indicates a leak, are you sure you temp gauge is correct, check with a thermometer, in other words warm the car up with a dial thermometer inserted into the ballast tank to verify.

Added info: I have a 1966 Mark 1a Tiger with a mildly modified engine, just under 300 hp. It has a flex fan, reduce size pulley, original radiator modified with 3 passes instead of the original 2 passes. I use a 170-degree F thermostat, horn hole blocking plates. The car runs at 170 degrees and during a 1 hour parade this past summer in 95-degree weather here in Missouri, it never went above 180 degrees, in fact since I finished the car it normally runs at 170 degrees and is quite fast. Finally, the engine was built using some of the suggested performance modifications in "Performance Tuning the Sunbeam Tiger" by Chittendon, Gordon. Other engine mods also made to improve reliability.
Good Luck.
Jim

 

[Austin Healer]

another weird issue I might relate is that the modern 302 water pump rotates the opposite direction as the ones for our cars... If you bought a modern pump..... just told the parts supplier you were building a 302, it's entirely possible that they gave you the wrong pump. They look the same... it's just that the impeller is configured wrong. 302's after the early 90's ran a serpentine belt... that spins the water pump in the opposite direction....

 

[Michael]

There are quite a few possibilities at this point. I would first figure out where the coolant is coming out, which is harder than it looks because it blows around. Leaking coolant acts just like overheating, and you can't trust the temp gauge. Heater core could be leaking, water pump. Mine had a small leak in the housing around the thermostat where the hose clamp goes. It would only leak when the motor got warm enough to build pressure in the system, and it leaked down the front of the motor. Pain in the butt to figure out because who checks the housing? Might be worth pressure testing the system with a pump: Stant makes a tester.

 

[Austin Healer]

I certainly agree about the pressure tester... also you might want to get a dye kit to see if you have exhaust gasses in the coolant. I had a car in not too long ago with a crack in one of the bores which allowed coolant into the bore... ended up tossing the block and getting a replacement... it would overheat before I got a 1/4 mile away from my shop...

 

[lee]

Thanks for all the suggestions.. In the pic of the motor you will see a chrome overflow bottle next to the alternator. This is where the water is boiling out. At the moment no heater core. No water in the oil.
Thanks again, keep the info coming.

 

[KettleCarver]

Lee:

I have also had trouble with my Tiger overheating after driving less than 3 miles. My problem turned out to be no spring installed in the lower radiator hose. As soon as you hit the gas, the hose would collapse and cut off the coolant supply. Just another thing to check that I did not see mentioned.

Good luck,

Marty

 

[Austin Healer]

Thanks for all the suggestions.. In the pic of the motor you will see a chrome overflow bottle next to the alternator. This is where the water is boiling out. At the moment no heater core. No water in the oil.
Thanks again, keep the info coming.

the engine that came in here with the cracked bore didn't have water in the oil either. it was basically pumping exhaust right into the coolant, superheating the water. we discovered this using a dye kit that reacts to exhaust gases....

 

[lee]

Thanks again. Problems found, this is a fresh rebuild with less than 50 miles on motor, you find a few bugs. Loose lower radiator hose and a lousy temp gage.

 

[sandy]

it's also possible to install the head gaskets backwards... they are clearly marked "FRONT"... they'll fit either way, but the engine will overheat if they are installed backwards... as this is a fresh rebuild, that's something that is obviously possible. I also don't think the expansion tank is large enough, but that's pretty minor.

usual checks are thermostat... (pointy end goes toward the radiator!!) should be 160 degrees, timing should be 10 degrees BTDC at idle, vac. plugged. make sure you are not running overly lean. tune with a vacuum gauge. a little rich is better than lean...

if the car is on the move, the fan is completely irrelevant. the air flowing through the radiator will provide all of the cooling.

make sure at idle a piece of paper will get sucked to the front of the radiator. if it doesn't, the fan's on backwards..

Always see the recommended 160 Tstat, really doesn't make a difference as long as it is open well before boiling point. Also great point on timing, Dan W. did an interesting article in the Club News letter on the effects on the Tiger. Seems like he got it figured out in any case.