VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1929-1932 Engine overheating

I have a 1930 Chevrolet wich has had its original engine swaped for a 1929 block. I believe the head is from a 1930. I drove the car last summer for quite some time and it always showed a tendency to run a bit hot. The waterpump was leaking so this spring I changed it for new one from fillingstation (the modern type with bearings). I also changed the baffle plate taking good care to have an tight fit between the pump wheel and the plate.
After this it still runs hot. Infact I get the feeling it runs even hotter than before. Ive checked the timing, the radiator shows good flow - so Im suspecting rust buildup in the block or a clogged water jacket. Right now Im giving it the citric acid treatment. Having flushed it out a few times during the week It doesnt indicate massive amounts of rust in the water though.

So my main question is. Are there any differences in the placement of waterjackets in the heads/blocks 1929-31? When I look down through the theromstat housing I see two corroded spots in the block matching open jackets in the head and gasket. One on the right side and one on the left. Just like there two undrilled jackets in the block.

No. The cylinder heads from 1929 through 1932 all use the same head gasket.

have you tried a reverse flush, where you flush under water pressure from the opposite direction of the stock flow.

You can dislodge more rust and debris this way.

If you do not have one, I would consider installing a 160--175 degree thermostat.

Think about what a thermostat does ?????? It keeps the water/antifreeze mix in the block until the coolant reaches the thermostats temperature setting then allows the coolant to pass thru to the radiator, where it drains from top to bottom with the fan removing 20--30 degrees, it stalls there until the thermostat opens and allows the cooled water to enter the block and start the process over again.


If the water/antifreeze just keeps running in a circle without the thermostat, it never gets a chance to cool and eventually reaches a higher temperature than you want.

The stock fans cannot draw enough air thru the radiator to cool the water down, therein lies the problem.

Loose fins in the rad core are another major source of overheating. Blockages inside the water jackets is another. Blockages in the cylinder head gasket.

If you search all the prior threads in the 29-32 and the 33--36 sections this subject has been talked to death.

mike

That I know. But will the jackets in the block always match in 29-31? Looking at my block I have open jackets in the head and gasket but in the block the matching hole is missing.
Some time back I did some work on a MOPAR flathead wich, without a doubt, had a missing waterjacket in the block. Thats why Im suspicious about things like this.

Yep have flushed in every possible way for the last week. :)

When I drive it I have a thermostat in. But I have removed it while flushing the system. Although thermostats werent standard until 1933. So for the first years most cars didnt have em.
Putting antifreeze in an these old engines is not recommended since they are non-pressure systems. Fillingstation has an article mentioning this (https://www.fillingstation.com/articles/cooling.htm) and Ive done some tests myself on my other Desoto. Anti-freeze in a non-pressure system will make the engine heat up more quickly, run hotter and overheat faster. If I remember it correctly the difference in my test between anti-freeze and plain water was around 50 F cooler with only water.

Since I use the standard honeycomb radiator there no traditional fins. It has no cold spots and flow seems ok.

The reason for me wondering about the waterjackets is that Ive seen factory made mistakes before. Had a MOPAR flathead wich blew pump gaskets all the time and ran hot. Pulled the head and pump. Compared the jackets with other motors and realized my motor had a missing jacket. Drilled it out and the problem went away. :)

What is the plug gap and timing set at? My 32 with all components in good condition and set at 12 deg BTDC would heat when still or pulling a long hill. I bumped it to 18 deg BTDC and it cured the problem. My suggestion is to advance the timing until it pings and then retard to where it stops. Plugs should be at .040.

There are no water jackets in the 1929-32 blocks except for the small water jacket that is on the very top of the block. Also, the missing matching holes that you are referring to on the top of the block were never there.

That is correct. The proper plugs to use that have the .040" gap are the AC C-C86 or C-87 plugs.

I also noticed the two holes in the head which do not line up with any holes in the block. I assumed they were used by the foundry to remove sand from the casting.

dan, the 12-18 degrees abv tdc and the .40 spark gap coupled with a four bladed fan is a good place to start (cheap and easy). also, i'd leave the aftermarket thermostat out, then see what happens. pax, jim ('30 coupe)

oops, i mean .040 gap. j

On old parts and outdated system, if you want to be able to drive in a very slow moving parade or heavy traffic , you have to have air flow thru the radiator to draw the heat out of the coolant. Failure to do that simple function will only cause the vehicle to run hot.

Just because in 1930--32 they did not have it, a thermostat, doesn't mean you should not strive to UPGRADE. Thermostats are still the same as they were back in the mid 30's. Holding water until a set temp , then releasing it into radiator to get cooled by 30 degrees.

Upgrading is finding a fan that will draw sufficient air across the fins in order to cool it.

Upgrading is capping off the stock rad top cap to the top tank and taking the radiator to a rad shop and having an inside the engine bay elbow installed and a proper 5--8 pound radiator cap installed.

The new radiator pressure cap will raise the boiling point of the water by 3 degrees per pound , = 18 on 6 pounds. So instead of 212 degrees to boil its raised to 230 degrees to boil.

Failing to understand...........next time put a bag over your head so the parade watchers will not be mocking you !!!

mike

Your post indicates that you are still using the original honeycomb radiator. If that is the case, the radiator was not a pressure radiator so if you apply pressure to the radiator via a pressure cap as suggested you will most likely spring several leaks in the radiator core due to its age. Even though your original radiator has good flow, the vehicle can still overheat since the radiator is 87 years old and the heat transfer qualities of the radiator may no longer exist due to the radiator's age.

If your engine get hot,near boil,or boil. Use https://www.evanscoolant.com/ I try it in several engines and the coolant works great. And you will not need to have a bag over your head in the the parade