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.

[RandyMettler]

….123

[RandyMettler]

Hello Ol' Ron

You a legend on Ford Barn

I Value your advice. The head gaskets that came off the motor were designed for the heads not the block following your advice, so that is what I will replace them with. The previous owner opened up some of the holes in the gaskets I removed. I have heard both sides of the equation. If one believes opening up the flow increases cooling than why not open up the gaskets and heads to match the openings ford designed in the block. If one believes restricting the coolant flow between components increases cooling than leave the restricted passages in the head gasket alone. This is fascinating to me. Any input is welcome. Although it is hard to argue with Ronnie roadster who favors increasing coolant flow. He built a 200+ mile an hour Bonville flathead without over heating. To top it off it started on its own power. Most Bonneville ride are push to operating speeds. Man would I loved to take that car for a ride!

[19Fordy]

Here's an 239 cu. in. 8BA with early style heads that were made by MCF in 1999. Water pumps are 8RT truck rebuilt with spiral impellers.The heads were deliberately designed not to use thermostats. Stock early copper head gaskets are used. Fan is 16 in.mechanical.
Radiator is a Walker. Are you sure your radiator is cooling properly? With engine warmed up take temp readings at the top and bottom of radiator. On mine there's a 10 to 20 degree difference depending on ambient temperature.

[tubman]

Boy, that engine jumps right out and hits you right in the eye.

[Ol' Ron]

In the early pre 49 blocks the holes in the block deck are there for core support during casting the block, as well as the water flow. The 8bA style block has most holes placed for cooling. However in the case of some rear block holes it was found that blocking some improved cooling. Yes hi flow does improve coolin, just like more oil through the bearings keeps them cooler.

[rotorwrench]

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The coolant doesn't flow real fast through the block anyway. Those restrictor holes in the gasket just redirect the flow. If you open them up, it just plain won't flow as well to the back of the block. Ford used coolant exits in the middle of the cylinder head of the older engines for a reason but they still didn't get quite enough flow to the back of the block. When they put them at the front on the 8BA they knew the flow was going to have to be modified to get an even amount of coolant throughout the engine block otherwise it will all go in the front and out the front with little flow to the back. This is just fluid flow dynamics.

[RandyMettler]

19Fordy, wicked engine!



I decided to reinstall the heads without modifying the head gaskets. I can always do that as a last resort.


I did temp readings with an interfered gun and the cooling on all cylinders front to back seems to be even. The odd thing is the passenger side of the block is running roughly 20 degrees warmer than the driver side. An again, all cylinders on passenger side running even, but 20 degrees hotter than the driver side.


The water pump on the passenger side seemed smooth and tight when I had it off, just like the driver side pump.


I noticed a slight tapping on cylinder 4. I located the tapping with a long screwdriver on the head near #4s plug. I don't believe I had the tapping before adjusting the tappet gap for the valves. Could the newly adjusted tappet valve gap be causing overheating and hard starting?



It starts cold, but is very hard to start once it starts to warm up. This time the hard starting is even at temperatures as low as 150, so not vapor lock/boiling fuel in the bowl. I bench tested my coil and according to my numbers the manufacture tech said it was on its way out. Although he had to verify with his supervisor. Could a lazy coil cause hard starting and overheating?


Regards

[flatjack9]

How did you test the coil? I doubt your tech knows what he is talking about.

[RandyMettler]

flatjack9 "How did you test the coil? I doubt your tech knows what he is talking about."



I have a MSD coil. I tested the primary and secondary coil ohm readings using a multi meter. I tested against the negative and positive poles and against the terminal the coil wire plugs into and both the negative and positive wires. Three readings total. My primary reading was .7 ohms. Factory specs are listed at .8 ohms. My secondary readings were 3.26 ohms. Both secondary readings should be the same and were. Factory specs are listed at 4.70 ohms. The MSD tech did not know what these numbers indicated until he spent 10 minutes on hold with his supervisor. He got back on the line with me and told me my coil was weak. I am still not too confident in his help. I sensed in his voice that he was not sure that his response to my question was accurate but was just trying to spit out what he could remember his supervisor telling him. I could have asked him why and I would have been place on hold for another 10 minutes but opted not to do so.

[RandyMettler]

Ol' Ron, Not that it matters, but I was born and raised in Westford Vermont. Ive been gone from there too long. I was raised in a house where the nearest paved road was 4 miles away and to this day still is. Now I live in a place where the nearest dirt road is much more than 4 miles away. I miss long dirt roads where the tree canopies join from both sides and are so thick they block out the sky. Growing up, it was just another drive into town. Now, it would be a drive I would try and remember. I don't know how long or why you have decided to live in Vermont but hope you appreciate where you are. Its a special place.

[Ol' Ron]

I like to run my engines at 180/200 Degs, now as for the timing, running retarded will cause over heating. Gota check the advance in the dist.