1949 8BA with 1946ish style Offenhauser cylinder heads overheating

[RandyMettler]

1949 8BA with 1946ish style Offenhauser Cylinder heads overheating

Has anyone successfully ran a 8BA with earlier style cylinderheads? I purchased a car with 1946ish offy aluminum cylinderheads and it is running hot. This seup is possible because ford designed the two different style era heads with the same bolt pattern and the coolant passages line up. I don't understand why my new copper 1949 headgaskets passage holes, on the gasket themselves, are so much smaller than the waterjacket passages on the 8BA block. If ford designed the sizes for blocks coolant output holes, why are the gaskets designed to restrict coolant flow?

Has anyone attempted to increase the size of the holes, on the head gaskets themselves, to match that of the engine block?

Has anyone successfully tried to bore out their aluminum cylinder head coolant passages to match the larger diameter holes on their blocks?

Also, the 8BA waterpumps incorporate two additional small coolant passage in addition to the large impeller output. One built into the top of the pump and one on the bottom. The top passage ports to the cylinderheads, technically bypassing the block all together. My 8BA block currently has these two collant passages plugged because the earlier style cylinder heads, I have, where not designed for this configuration. The 1946 water pumps did not have the upper passages. Does anyone know why the 8BA pumps did this?

Regards

[34PKUP]

"Heads overheating" means what?? Relative to what?

[rotorwrench]

The 8BA normally has the thermostats in that area. It is likely just a bypass where you plugged the ports. The head gaskets have small holes to slow the flow so as to provide a small amount of control to parts of the block that weren't being cooled as well as others. FoMoCo wanted coolant to flow to the back of the block a bit more to even the cooling process out.

[Ronnieroadster]

Built many 8BA engines with early 59A style finned aluminum heads with no heating issues. However i do pay attention to the water hole diameters. I prefer to not super heat the water which is caused by many gasket types that have those small diameter water holes to so called force the water to another area of the block which simply adds lots more heat to the water before it moves into the head and then out towards the radiator. Blocking water flow in a Flathead Ford V-8 block is not a good thing in my opinion. However my real world experience is where i get this opinion it works for me on the street and even at 200 MPH
Ronnieroadster

[RandyMettler]

Originally Posted by 34PKUP

"Heads overheating" means what?? Relative to what?

I am glad you asked
My heating sending unit is mounted to the top center of my Offenhauser cylinder heads. The in-dash temperature guage got as high as 210 degrees. My infrared thermostat verified that the in-dash temperature guage was reading correctly when I pointed it near the temperature sending unit on the heads. I did not measure the actual block but plan on doing so when it is running again. I have a new Griffin aluminum radiator, the pistons are bored to .080 and I have verified that the water jackets are not plugged. I run dual 94s without progressive linkage and was told I have MSD breakerless, magnetic pickup with reluctor type distributor. So no points and no vacuum. I had 180 degree thermostat installed and the high cylinder head readings were taken when the air temperature was 72 degrees when driving on the interstate at 70 miles an hour and at idle. I also verified the waterpumps were rotating smoothly. My compression is 110 on all cylinders

If the offys from the 59A are not causing heating issues it could be timing, coil, ignition module, vacume leak or leaks or the carbs running too rich (which they definitely are).

I may experiment running with one or both plugged power valves but this may cause a overly lean mixture when driving and cause engine damage. A progressive linkage setup may help. Running two 94s halfs the vacume so this means the powervalves are opening early or even at idle. I heard from Summit Racing there are vacume assists available to boost the vacume but my 94s do not have the port and venturi combination option so I don't know how it would be installed.

Thanks for your reply

[RandyMettler]

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Thank you for your information and time

Do you alter your cylinder head gaskets or do you have a source that makes gaskets with larger coolant openings to speed up the circulation a little? I would like a little more info. I suppose I could put it together and run it with the copper gaskets unaltered betting on the restriction is good thought, more time in the radiator more time in the block. It seems to me circulating faster would be advantageous if your radiator and fan are pulling strong. The design of the pump impellers seem to be inefficient to begin with. Do the flat head pumps circulate quick enough without restriction? If it runs hot, I can try opening the gasket holes a little or a lot.
All input is welcome and viewed as valuble

[RandyMettler]

...

[paul2748]

wrong thread

[Ronnieroadster]

Originally Posted by RandyMettler

Thank you for your information and time

Do you alter your cylinder head gaskets or do you have a source that makes gaskets with larger coolant openings to speed up the circulation a little? I would like a little more info. I suppose I could put it together and run it with the copper gaskets unaltered betting on the restriction is good thought, more time in the radiator more time in the block. It seems to me circulating faster would be advantageous if your radiator and fan are pulling strong. The design of the pump impellers seem to be inefficient to begin with. Do the flat head pumps circulate quick enough without restriction? If it runs hot, I can try opening the gasket holes a little or a lot.
All input is welcome and viewed as valuble

I alter the gaskets as needed its easy to do using a rotary file in a drill press i also use round mounted stones. To increase the gasket hole diameter i gently push the gasket into the rotating tool by hand. Also during the process I rotate and rock the gasket so the cutting of the material composition or copper is removed. Its a slow process but worth the effort modifying the gaskets as needed. Obviously the the thermostat should be the flow controlling device having extremely small water transfer holes in the head gasket certainly reduces what the thermostat can do.
You mention some about the carbs I doubt the heat is caused by a lean condition so if the spark plug color is a light to dark brown then things are pretty good. Lean condition plug color will be white and thats hot for sure. A further test you can do with the heat gun since you see how hot the top of the heads are now put the gun at the block by the water pumps. Also compare the temp going into the top of the radiator compared to the temps at the lower water outlets. The heat gun is a great tool for learning about the cooling system especially on the Flathead.
Ronnieroadster

[flatjack9]

I've been running early heads on my 8BA block for over 20 years now with no overheating problems. I used the early head gaskets and made no modifications. My engine is 276 cu. in. I would check the upper and lower tank temperatures to see if the radiator is sized properly.

[40cpe]

You don't say what vehicle you are driving, but from experience I know that running 70 in a car/truck that has a lot of wind resistance forces you to give it more fuel, and more fuel causes more heat. My car is much more comfortable at about 60 mph.

[rotorwrench]

Barney Navarro mentioned that they used to put a small collector behind the water pump and attach copper tubes to get water to flow to the back of the block on the prewar and immediate post war engines. He also stated that the 8BA design eliminated the need for that.

We ran the 8RT trucks with heavy loads of grain during summer harvest when I was a kid in KS and we never had one overheat. After folks thin the cylinder walls a bit and start modifying for more power, it gets to be a more delicate balance on keeping them cool when running them hard.

[RandyMettler]

I have the cylinder heads currently off the block and the piston tops are stamped 0.80. I was also told when I purchased the car, the stock cam had been replaced with a lumpier cam. The car does idle like it has a race cam, but I believe the rough idle is due to timing and air fuel mixture ratios carbon fouling my plugs. The cam in the car is from a 59A block. The bigger pistons may be contributing to the overheating as you mentioned.

Thanks

[RandyMettler]

That great news. I really did not want to replace the offys cylinder heads with 8BA head if is not necessary. Throwing money at a car does not always fix the problem. I can check that off the list.

[JSeery]

I'm guessing you mean 0.080 over on the pistons. 0.800 would be a bit on the large size.

[flatjack9]

80 over pistons are not going to cause overheating. Generally a lumpier cam will require a little more spark advance. Retarded timing will cause overheating as will a lean fuel mixture.

[tubman]

"Flatjack9"s post leads me to ask : What kind of distributor and carburetion are you running? Mismatched components in these areas can cause lots of problems.

[rotorwrench]

I noticed the 59 series cam mentioned. It doesn't have the distributor drive gear. It's a good choice if converting the front for early style pumps and ignition.

[RandyMettler]

I'm glad you asked.

The distributor is a front mount breakerless MSD electronic crab style. I am told it is a es. It does not incorporate vacuum to advance or retard the timing. It uses weights and springs and I believe it only advances. When the centrifugal weights are out at low load situations on the interstate, I do not believe it can retard the timing which I believe the vacuum break model is setup to do.
The carbs are dual 94s. They are the 94s without the port and vacuum option. 3.5 power valves, 47 jets in the bowls. And yes, it is running very rich and carbon fouling the plugs.


If you mean water pumps, they are the stock setup for the 8BA and not the 59A. I don't know if there is a flow rate difference between the years, but would be willing to change to whatever model is most efficient.

[Ol' Ron]

If your gona use 59 heads on an 8BA, or 8BA heads on a 59 block. You must use the same head gasket as the head to insure proper cooling. I've done this quite often and never had a problem. Plus I always have mu blocks baked cleaned.