Overheating 8ba
 

Friends newly rebuilt 8ba overheats with thermostats or without,same thing,this is in a 41 2 dr,water wetter no help,timing set on mark.any ideas would help.

Re: Overheating 8ba
 

Does it overheat sitting and idling, or going down the road, or all the time. Knowing will help in diagnosing this.

Re: Overheating 8ba
 

This is what was posted on Vanpelt’s web sight. Looks like it hits the high points.

In no particular order, things to look for and correct when your flathead overheats.

1. Be sure that thermostats are installed. The 1937-48 motors have t'stats installed in the upper radiator hose, just above the water outlets on the heads where the hoses are clamped. The 1949-53 motors have t-stats installed in the front of the heads, inside the radiator hose outlet castings.

2. Be sure that the thermostats are not installed upside down. The bimetal strip or wax plug should be facing the heads.

3. On 1948 and earlier engines be sure that the hose clamps keeping the thermostats in place and the hoses attached to the heads are not too tight, preventing the thermostats from opening and closing.

4. Be sure that the radiator cap is the correct one for the system you have. Pressurized or non pressurized. If it’s pressurized, replace it with a new cap of the correct rating.

5. Be sure that the water pump belts are tensioned correctly. Too loose, and the pumps will slip and not draw enough coolant around. Too tight and you prematurely wear out the bushings/bearings in the pumps.

6. Be sure that the radiator is clean. Shine a light through the fins. If you can't see the light, clean the fins by brushing the front lightly with a soft bristle brush to remove the exterior debris (mostly bug remains). Then, use the spray nozzle on your garden hose to flush the rest of the debris out of the fins from behind.

7. Be sure that the radiator hoses are not kinked, preventing coolant flow.

8. Back flush the old coolant until you get clean water. Note: if the block has years of accumulated corrosion and crud in the water jackets, a simple flush may not remove this material. The best method (and the most expensive option) is to remove the engine and tear it down to the bare block casting in order to have it acid dipped. This process will remove everything but the good cast iron. Once the block is CLEAN, it can be reassembled and then fresh coolant (50/50 mix) added to the system.

9. Be sure that the water pumps are not worn out (loose shaft/pulley, leaking seals, corroded impellers). Replace as needed.

10. Check to see if the radiator is plugged with years of rust and scale. Removing the upper and lower hoses can provide a simple visual inspection. If the radiator is suspect for these or any other reasons, have a professional radiator shop check it properly (including a pressure test AND a flow test). Have it repaired or replaced as needed.

11. Be sure that the ignition timing is correct. Timing that is too far advanced will cause the engine to overheat. Adjust the timing to within factory specifications. Pre 1949 distributors should be removed and adjusted on a distributor machine.

12. If the engine is coated with years of grease, oil, and dirt, clean the block by scraping and then pressure washing.

13. Be sure the brakes are not set too tight as dragging brakes make the engine have to work harder to move the car.

14. Be sure the tires are properly inflated. Low pressure creates more work for the engine and wastes fuel as well.

15. If the engine temp gauge still shows overheating, but visually it doesn't appear to be, the gauge could be reading wrong. Or, the temperature sender(s) could be defective. The sender can be tested in hot water with a volt/ohmeter to determine if it is functioning correctly. An infra-red thermometer can also help locate hot spots in the motor and indicate actual temps.

16. Use a coolant test strip (available at most auto parts stores) to check the coolant for evidence of exhaust by-products. This could indicate a leaking head gasket, or a possible crack in the block.

17. A blocked exhaust system can definitely cause overheating. If the vehicle has been stored for some time, rodents may have climbed into the exhaust pipe and built a nest anywhere from the interior of the engine to the exhaust outlet. If you suspect this to be the case, and you can not feel normal pressure at the pipe outlet, disconnect the pipe from the exhaust manifold and try to blow compressed air though it. You may have to completely disassemble the exhaust system to locate and remove the problem.

Sometimes, over time, rust can gradually block the louvers inside the muffler baffles, resulting in serious blockage. Replacement of the muffler is necessary. Also, if the vehicle has a temperature controlled exhaust "warm up" damper at the manifold, this may be corroded to the point that it remains in a closed or partially closed condition. Remove and repair the valve if needed.


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Re: Overheating 8ba
 

Don I had similar problem with my 59a engine this spring. We checked all the previous mentioned things. Lastly removed the radiator which had already been boiled by a shop took it to a different shop. The radiator was left in tank for 3 days taken out and then put back in for 3 more. Problem was solved by a thorough cleaning. So make sure you find a good honest repair shop. Boiling for a few hours won't do it.

Re: Overheating 8ba
 

Am going over to help in morning taking another dist to changeout,will checkto see if heating up just sitting or moving, and get more info,not sure if radiator was cleaned good,will report back

Re: Overheating 8ba
 

Make sure you have a 4lb pressure cap that the rubber extended end at the
bottom hits and seat on the washer like seat at the bottom of the filler neck.
REMOVE any thermostats until problem is solved. Fill with water or coolant
up INTO the filler neck. Put a large house type fan on high speed AGAINT
the center of the grill. Run the engine at a fast idle or equal to 20 MPH and
check and write down the temperature taken on the top of the thermostat
housings. Take the temp every 5 minutes. It should stabilize at a temp of
about 180 after 20 minutes. This will be temp you will have driving at 45
MPH. If it don't get hot and you loose coolant out the over flow you have a
bad pressure cap or one that is not seating at the bottom or exhaust pressure
in the engine cooling system. Temps over 212 will cause coolant to come out
the overflow. These engines have a tendicy to heat up in hot weather at long
idle periods or slow stop and go traffic. The forward motion of the car forces
outside air through the radiator. It also cools better heading into the wind.
G.M.

Re: Overheating 8ba
 

What kind of fan set up are you using?
Is it positioned so as to pull enough air?
Shroud?

Re: Overheating 8ba
 

Back in the day, a radiator shop would pull at least one of the radiator tanks and rod out the coolant tubes. Boiling the radiator will not take all the crap out. Using the proper rod and going through each tube is the only way to insure no blockage. A flow check should show if there is significant blockage. It's hard to find a radiator shop that will do this now days. Just about every town of any significant size had a shop like this back in the day.

On your distributor, if it's a load-o-matic, make sure that vacuum can is working properly. If it has a leak in the diaphragm, there will be no advance at all.

Re: Overheating 8ba
 

Went to Jims this morning,thermostats in,car ideling did not temp normal ,went for 5 mile ride,had to get back quick high temp,used heat gun to check,engine was 212 at outlets,rad temp was 180 give or take,bum of rad was even cooler.
Pulled dist ,put on machine re set dwell to 28* ,checked movement of advance and dia, ,rall was good,dist was ar 30* to start with,put all back ,set time to mark.double checked rad cap,7 # ,water about 1/2 tank,no drag on brakes,took for ride,same thing,
Radiator was supposed to have been cleaned and checked but thinkingthis might be problem,,,have a 6 blade fan we might try first,thanks for listening also heads and intake have all been retorqued,all new duel exhaust/ brockmans,could they been in backwards???

Re: Overheating 8ba
 

If it overheats while driving the fan isn´t going to fix it.
Check so you don´t hav combustion going out in the cooling system after that get the radiator fixed.
Just my thinking on it.

Re: Overheating 8ba
 

Ordered new aluminum radiator today ,think this should cure heating problem!!

Re: Overheating 8ba
 

Please keep us posted on how it cools and who makes it.

Re: Overheating 8ba
 

Not to be a wet blanket but -- Cracked block and blown headgasket can also cause overheating.
Want to know for sure that she's tight - find some of this online or at your local parts store --
http://www.blocktester.com/instructions.htm

Re: Overheating 8ba
 

A new radiator is not going to fix engine cooling problems.
Fix the compression leak or whatever the cause is first.
G.M.

Re: Overheating 8ba
 

Block was cleaned and checked for cracks when rebuilt by long time engine builder, pretty sure engine is ok but don't know about old radiator,we'll find out in a week or two. C

Re: Overheating 8ba
 

What kind of heads are you running? Did you re-torque after a few heat cycles? I put aluminum heads on my 8BA and it got hot a few times during break in because exhaust heat was making it's way into the cooling passages. I retorqued the heads and problem was solved. Also, the motor may get a little hotter than normal in your first 100 miles or so if tolerances are tight.

Re: Overheating 8ba
 

I doesn't matter how many engines your builder rebuilt
you could still have a leaky head gasket. G.M.

Re: Overheating 8ba
 

My '41 had an ill fitting truck radiator which dribbled a little (Barrs fixed that) but cooled the stock engine very well. Replaced it with a Champion aluminum radiator rated for 500 hp, and have been fighting cooling problems at idle ever since. Can't blame it all on the radiator though, because the engine was souped up at the same time. Fan shroud goes on this week.

Re: Overheating 8ba
 

All the "fancy" radiators have fins and tubes tighter and extra rows which means you need a higher pressure to move air through it.
That fan shroud shoud fix the pressure you need.
Doing things better then you need often gives you new issues to solve.
Gives you a new fun challenge to solve :D

Re: Overheating 8ba
 

I don't mean to rob this thread but I also have a overheating question. I have a 59a engine, new Dennis Carpenter water pumps, Stant 170 thermostats, 50/50 antifreeze. I have checked the timing and it is good. I am using a stock '32 radiator. The car seems to cool fine around town with low RPM's (180-185), but if I get on the highway or gear down for a climb with higher RPM'S it goes up to 210 and up. Any ideas?