VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1933-1936 1936 Master 207 overheating

Does anyone know if there is an after market pump or conversion to help the 207 engine water pumps to move more water and keep the engine cooler? I know this subject is a recurring theme, but I have read all of the old service manuals trying to get the overheating problem to go away. The pump is new, the radiator is rebuilt and very clean, engine is rebuilt and runs great. An infrared heat gun anywhere on the block reads no more than 160 degrees any plce on the external of the head and block. Any wise input would be greatly appreciated.

If it reads no more than 160 on the block why do you think that its overheating?
I use the area right next to the temperature tube at the rear of the head to check temperature.I also compare it with the left side of the block water jackets the the upper and lower radiator tanks and the thermostat housing.When completely warmed up and engine at a fast idle all should be with in 10 degrees.
160 degrees sounds wonderful.

Gene. Thanks for the reply and yes, at 160 dgrees, everything sounds great. However, I am still getting an occasional boil over from the radiator AND the temp gauge on the dash gets to between 185 and 200 degrees. Something just doesn't seem right. I thought it might be air in the system, but even the water pump packing is tight and not sucking air (common overheat problem). I'll try the temp reading where you suggested and see what it reads as well. IN the past I had a heck of a time finding a replacement radiator cap for the engine, but finally found one that sealed tight. It's actually an oil fill cap that I understand is a common fix for this mysterious year radiator cap replacement.

It should not be throwing out water at 200 deg.My '34 will run arond 180 in summer weather.Will getup to 200 in hot weather (these temps are at speed).When in traffic it will go higher and hit the top when engine it shut off - but it has never lost any water.emp. needle has been pegged at the top several times during long 4th of July prades...no water loss.I do run a 50/50 coolant mixture which will raise the boiling point several degrees.
If you are at a higher altitude it will boil at a lower temp.We are at about 800 feet here in Wis.
The'36 is a better cooled engine than a '34.It has a much larger water pump,cooling system and full length water jackets.

Ted,
I have a '35 which is the last year for the small engine water jacket. As I recall the '36 increased coolant capacity by 5 quarts, so you shouldn't have an issue if everything is in order. Under what conditions do you see the temp gage rise? Are you idling, pulling up a long hill or in stop/go traffic? Or does it just occur randomly while driving?
I appreciate your comments about a 'rebuilt' engine. Mine was alledgedly 'rebuilt' but I had to remove the engine last year and pressure wash debris and rust from the head and block. Now she runs as cool as the other side of the pillow! We may be able to discount your engine as having blockage since you ran a temp scan. Any chance you might have missed an area? Let us know more so we can assist!

Coach

Was just giving this more thought.Do not overfill the radiator.If you can see the coolant at the bottom of the tank when the engine is cold the radiator is full enough.Above that amount and the coolant will expand and puke out.

Coach and Gene
Thanks for all of the input. The temp change happens when the car sits in idle or I am doing a lot of stop and go. And I appreciate the parade issue. Nothing like a blistering hot slow moving parade to test the coolant. The 50/50 mix might be a small part of the problem as well as over filling. It's good to hear that 180 to 200 degrees happens with frequency on other cars. The radiator cap might have been a lot fo the culprit. It's replaced now but I am going to add the other suggestions from all of you to my check list.

Thanks for all the help!!! You guys are the best.

Drive often and drive chevy.

My '34 came out of Moberly.I bought it in 1970.Was a one owner car.The brother of the widow that owned the car said it was never farther from home than Columbia.
In 1985 I drove it to Moberly and we stayed there overnight.The next day we went down to Columbia and then over to St.Charles for a meet.

If your engine runs at 160 deg in summer weather and goes up to 190 or so when stopped etc. it is perfectly normal.My '39 does the same thing and it has a new radiator and block.

Gene
Moberly to Columbia? I live in Columbia. Drove the car to Bevier once. Nice to meet another show me guy. Thanks for the info. I feel better about what I have.

Gene
A P.S. and a little history. My car came out of Wisconsin in 1980 from the second owner of the car. Dad and I bought it to restore. He didn't live long enough to finish it with me. He took his driving test at age 15 in Amherstburg, Ontario Canada in a 36 Master. He always had a soft spot for the car so I finished the restoration 10 years ago in his honor.

If you think your car is running hot especially at slow speeds you could always put on a truck four blade fan as they ran a greater pitch to the blades and pumped more air thru the radiator.

I learned to drive in a 1934 Master.Took the test three years later in a 1942.My second and third cars were 1936 Masters.
Where in Wisconsin did your '36 come from?

The larger truck fan blade makes them sound like a truck.My '34 rolls along at 60MPH in silence.Just a slight hum of the fan.

Pickup Man...good idea. Thanks.

Gene
Car came from right outside Madison. The guy we bought it from was in his 30's and drove it to work every day.

Hi Ted, I thought I might throw my 2 bits worth in. I couldn't help but notice your statement about making the water run faster maybe with the use of a bigger water pump. After driving a lot of older cars in my life I have learned that it isn't the water being pumped faster that cools your engine, but actually the slowing of it. If it runs too fast it doesn't have the time to actually cool itself in the radiator, if you slow it down, it cools more before it recirculates into the block and back. If it is too fast you are circulating hotter water. Does this make sense to you? Now, I don't know how this applies to your car, unless you changed water pumps.The fan also plays a major part in this, is the fan pulling enough air? On backwords,if so its pushing air. The water usually gets slowed by a thermostat/ Like I said, just wanted to throw my 2 bits worth in.

Ted
Air Force is right, too fast a flow is as bad as not enough flow. If my memory is right about 80 gallons an hour is the ideal flow through the radiator for effective cooling.
Most water pumps are designed for 130 gallons an hour. The thermostat restricts the flow to about 85 gallons at full open.
I have seen somewhere on this forum that on some models there is a pipe inside the block that if rotted out will cause overheating.
Tony

masterbuilder,
A mate of mine with a '38 Business Coupe(since sold to a bloke in Victoria,Australia),was having very similar problems to you.
He had the radiator tested 3 times(no problems apart from the water baffle tube rusted away),the block and were cleaned and flushed,and only a little bit of scale found.
I asked him if he'd re-built the pump,which he said he'd had done,and we pulled it off to study it.Comparing the "re-built pump"to an untouched one,we discovered that the water pump impellor supplied with the re-build kit was smaller in diameter than the old dirty pump we were using as a comparison.
It appeared that who ever had the new impellor cast,used an old worn impellor as a pattern,not having it cast from a proper pattern to allow for shrinkage and machining,and the "new" impellor was physically smaller than the old one.The impellor vanes were shorter in height than the old ones,and the outside diameter was smaller as well.
I machined up a mandrel in my lathe and fitted the "new" impellor to it,and we saw that,while the shaft bore and the seal
recess ran true to each other,the vanes had up to 0.080" axial and radial runout.
I machined up a new impellor from a bar of cast iron to the size of the old impellor,and after allowing for metal loss due to corrosion,we reassembled the pump and fitted it to the car.
Problem solved!The car now ran much cooler(it used to run at a constant 190 degrees even on a cold day!)and didn't boil after
even a short run of 20 minutes to my place or lose any water.
Sorry to be longwinded with this,but I thought it may be of interest to you or any one else witha similar problem.