Yet another flathead overheating problem

I know this topic has been exhausted but after reading many threads and trying a bunch of things I am stuck. 50 8BA kind of unknown motor good looking water pumps and 160 thermostats. I have been running the car for a few years no problems but this past week the car got very hot coming up the hill. I figured the mismatched temp gauges might be at fault so I replaced them with two SW gauges are saying the same temps. At an idle its running 220 and if you try to drive it, it creeps on 250. The left bank is running about 10 hotter then the right. I have checked both water pumps which appear to be new, the inside of the engine has no rust build up what so ever, tried 160 and no thermostat, and have played with timing as well as the carburetor quite a bit. The Radiator is recored and there is no water in the oil or bubbles in the radiator. All this has had no effect. Any thoughts?

 

How hot did it get going up that hill? Are you losing water?
You may have one pump failing causing the whole system to overheat.
It's unlikely but gravity might have stirred up some sludge/scale in the water jackets. Or you could have blown a gasket or worse cracked a block.
Use your nose, if you take off the radiator cap and smell a slight hint of gasoline instead of coolant you may have a cracked block or cylinder. With the cap off if you rev it and water gysers out the outlet you have a big problem.

 

Collapsed radiator hose!
Belts slipping?

 

It hit 250 on my other gauges which is where they stop. Not loosing any water currently. Good belts and hoses that appear to be fine to me. After smelling the water it doesnt smell off to me and I took the temp sending units out and ran it just to make sure the pumps were pumping and it was running water out both sides if that is what you mean.

 

Timing is critical on flatheads, check timing and make sure it is correct, one bank will generally run hotter than the other, thats normal, 8BA are you running stock dist or something else? How are your lower hoses, they sometimes collapse and restrict water flow.........

 

Original distributor hooked up to rebuilt holley 94 currently running 6 btdc or atleast thats what the mark shows and that is where it appears happiest. the bottom hoses do not appear to be collapsing at this time.

 

Sounds like the radiator has some type of blockage. To determine if its the radiator you need a temp gun. With the motor running at idol take a temp reading at the lower hose and the upper hose on each side of the motor if the temp is the same at both hoses the radiator is the problem. You should see at least a 15 degree difference from top to bottom. Also if your using a mixture of antifreeze and water that's another problem area. The mixture is fine for a higher boiling point but in a flathead what you need is coolant that will disapate heat fast. The best way to do that is with just straight water no additives at all.
Just going to straight water will lower the running temp in a flathead by 10 degrees it works every time.
Ronnieroadster

 

Alright thank you that is some very good advice Ill have to try that out and see what the temperatures are. I am running strait water with no antifreeze at this time.

 

Overheat at idle is often caused by retarded timing.

 

I had a bad water pump that looked good but it wasn't moving the coolant, I replaced it with two new ones, and a new rad and electric fan, haven't had a problem since.

Brent

 

i thought 4 BTDC was normal timing for a flatty....

 

Dump the og dizzy. Get a gmc bubba dizzy. The 8ab loadamactic dizzies are not great. Start there.

 

try touching the water pipes. It could be the senders that are wrong. I was told if you could place and leave your hands on the pipes they were about 150, if you could just barely touch them, they were about 180. do this at your own risk and discretion of course, but regardless of what the guage reads, if i can touch the pipe, i figure its not too hot

 

Even if its not timing related, lose that distributor and get one from Bubba. It will make a HUGE improvement in performance, also another thing to check. Pull the lower hoses and make sure the pumps are not partially plugged up with crud, you can stick your finger up in there to make sure. You can also put a piece of nylon stocking in the upper hoses to see If you can catch any rust or debris coming out of the motor. runit on the road for a bit then check to see if it caught anything if it did you know you probably have a radiator full of crud.

 

Might also drain and fill w/white vinegar,run for2 wks+- flush with baking
soda.It works.

 

I had one with a cracked cylinder that would idle and not loose water. Driving it would loose water and quick. When the engine was revved with the radaitor cap off it would spray water, like a volcano. There was no water in the oil, no oil in the water. Combustion g***es were only being forced into the system at high rpm or when the engine was under load.

 

I don't think it is a cracked head or block, because he said he's not loosing any water - correct?

 

My Cadillac was overheating last summer and a guy suggested this.Im giving it a shot right now. The baking soda is new to me .

 

Soda neutralizes the vinegar.Theres a thread on fordBarn about this.I"ve used vinegar to de-rust parts.There's also some good info on Ford Garage about
electrolis(sp) rust removal.

 

Thanks Tex

 

Step number one before you go out buying stuff

Confirm there’s no cracks or head gasket issues.
Check the coolant for combustion gas’s ……. go to the parts house and get the kit.

Or go buy a bunch of parts for a motor that may have cracked block …. Its your call

 

This is why i'm having my '48 59AB block checked first.....

 

PutPutBoom.......
What is concerning me is..........You say you've been running this engine for two years an NO Problemo ? Trying to figure What happened recently to cause the problem ? Can't help but
think "some kind " of blockage in the flow......
I'd have the Radiator flow checked.
Been told many years ago that those engines
circulate the water Too Fast, so thermostats
(180-185) help to slow Flow, also.....old trick was to cut every other w-pump impeller off. Another
trick was to put washers in water p***age under
head in block, therefore slowing water circulation and giving Radiator more time to cool water.
Never heard "that" about running striaght water ?

Advise Us as to what you find that corrected the
Problem. Please. Thanks & good Luck.
smokey2

 

I appreciate all the comments. I am interested in trying a distributor from gmcbubba or a original mallory if I can find one. The water pipes are to hot to touch so I am lead to believe it really is that hot. The white vinegar is interesting i have used it to clean a number of other things such as gl*** with build up but I had not thought about running it in a engine. Not currently loosing any water no. It seems as if something may have blocked a water p***age so I think I will tear the heads off just so I can see what I have. I have yet to spend any money on it I am just playing around with stuff I already have currently. I will update when ever I figure out what is the cause of this.

 

I had a similar issue. I had been driving my shoebox for a year or better when it started running hot. The rust and scale that was in the motor finally started breaking loose and plugging some of the radiator I would take the radiator out and turn it upside down and shake it and I could hear the debris flopping around in there. I would then flush it out while upside down and put the nylon stockings in the upper hoses to catch the debris. Removing them to clean occ***ionally and It finally quit coming out of the motor.

 

ANd it stopped running hot too?Same happened to me.I Bought my Cadillac drove to hell and back then I parked it for the winter.The following summer the same thing .I'm giving it the vinegar treatment right now and can see gunk on the Rad cap .I will flush again next week. I hope the OP has it figured out soon too.

 

I'm sure that the new dizzys are great but that's not going to cure this problem. It should run cool with the factory distributor.

Before you pull the heads you can pull the radiator and check for blockage. See if you have had any debris that has turned loose. I know of one low mileage 51 Ford car that several pounds of casting sand was found in the block during overhaul.

If no blockage is found pull the heads. Look for cracks, sometimes you will find cracks between the cylinders. As long as these do not go down into the cylinder, most of the time these can be sealed. Cracks in the valve seats are much, much worse.

If no cracks are found try replacing the water pumps.

Could you have a bubble? Sometimes you think the coolant is full when actually there is an air bubble in the system, so before anything else make sure the cooling system is properly filled.

 

You say "rebuilt carb", are you sure it's the right one? A 59a style 94 won't work with your distributor. Did the heating start soon after the carb install?

 

A bubble did not appear going up a hill, the timing didn't change suddenly

 

I tend to think your stock distributor is at fault. Have you checked the advance diaphragm on the distributor? Are you running holley 94 carbs? Do you have the vacuum advance hose connected to the venture port on the holley 94"s?? You call this an unknown motor.... Is this the first time it ran in warmer weather? Follow the basics... lean condition? retarded timing? Pump circulation? Loosing coolant at overflow? Water vapor in exhaust? How do you know the block is clean?? Run some 100% vinegar through it for a week or two. Cheap and it will never hurt to clean these ever so often.