Engine Overheating

[Ed Saniewski]

Going to and coming home from Gettysburg I had a problem with the engine overheating. We traveled 160 miles and a lot of it was at 45-50 MPH. I noticed that if I opened the GAV adjustment 3/4 to 1 full turn that the temp would come back down to normal, but when I came to a stop the engine would start to stall due to the rich mixture. Dose this mean that my main jet orifis is restricted or too small? Or is this just something I need to do when driving in hot weather. Thanks

[TinCup]

Ed I have learned that it is rarely a one item solution on overheating. You have already found the first of what will probably be a multi item solution. I like to use the certified jets from Renners corner to insure that the jets are flow tested. At those sustained speeds any weakness in the radiator and higher temps will show themselves.

[Jacksonlll]

Running rich always runs cooler. Not a solution for a plugged radiator. Your radiator should flow about 36 GPM. Most of our cores are plugged to some extent. Nothing wrong with your carburetor.

[Rex_A_Lott]

Retarded timing will make one run hot too. Was it puking water? The whole time? Just a little? What makes you say it was running hot?
Good Luck

[Ed Saniewski]

The temp would be fine for a long while, then start to climb. If I noticed it soon enough and opened the valve, it would cool down. If I did not it would overheat and slowly push the water out. The other two cars running with me had no problem. I will try another carb and take it out for a run and see if the results are different. Thanks.

[John/CT]

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I think you have a cooling problem, not a fuel problem. This high speed overheating characteristic has been observed with inadequate replacement radiators. If your radiator passes the flow test recommended by JacksonIII above, drain the radiator and measure the contents. If it measures less than 3 gallons you probably have a replacement radiator with fewer tubes than the original. It's okay around town and short tours but offers inadequate cooling for sustained high speeds. The solution is the find a good old stock radiator or get one re-cored (+- $700 in the northeast). We have seen the older repro radiators that held 2 1/4 gallons.

[phonconn]

Ed,
I agree that there is a different problem than just the carb, BUT when flying we lean out the carb as altitude increases but with a proper Exhaust Gas Temp gage if it is too lean then the engine heats up a lot and can damage internal parts.
So by enriching the gas mix does make the car run cooler and can be a good temporary fix while traveling.
Also anti freeze is an enemy of a non pressurized cooling system and you may have some snot in the tubes due to the anti freeze but it could be a volume issue as was stated by John/CT. Gary Bergbower in Southern Illinois makes a high volume radiator with flat tubes that cools better than any radiator we have tried or are aware of using.
I think that the flow rate of a good clean original radiator should be around 50-52 gal/minute. Post your results as always is interesting to find out the solutions to overheating problems.
In St Louis in 88 with temps over 100 degrees everyday we beat some of the impellers ears off so the water pumps didn't pump so much water but the bottom line was anti freeze snot in the tubes.
Good luck and look forward to having you join us in Branson Missouri next June.
Dan B

[H. L. Chauvin]

Hi Ed,

For the past 20+ years of Model A Forum questions about Model A engine overheating, everyone appears to be always looking for some inexpensive solution to solve Model A engine overheating problems ...... timing, carburetor jets, brake shoes dragging, low tire pressure, etc., etc., while trying to dodge the cost of professional cleansing of an old clogged radiator, radiator re-coring, or dodge the cost of buying a new Model A radiator.

In most cases, 80+ year old radiators, (and younger radiators), have tubes that are clogged with minerals which cling to the radiator tubes, thus not only reducing rapid water flow, but also not allowing the transfer of heat.

Water from wells or streams in constant contact with the earth are loaded with dissolved minerals which are not filtered even with modern day potable water filtration; hence this type of flowing warm water after many years leaves earth's mineral deposits in Model A radiator tubes.

Constantly using either distilled water and/or rain water can prevent radiator mineral deposits.

To top it all off, recommended 50% antifreeze can prevent old Model A engine rusting where rust particles can easily clog a Model A radiator.

If you would like to try antifreeze in a "clean" radiator one day, we have successfully been using 50% Prestone for over 65 years in vintage tractors and vehicles ........... which in addition, we have noticed Prestone is 100% Snot Free.

Hope this helps someone in the future with 80+ year old Model A engine overheating.

[Tom Wesenberg]

I agree with H.L. that deposits of minerals in water is the problem, along with rust from people who use plain water.
I always use 50% antifreeze in my A/C WD tractor, my Studebakers, and my Model A's and never get deposits.

[old31]

Originally Posted by phonconn

Ed,
I agree that there is a different problem than just the carb, BUT when flying we lean out the carb as altitude increases but with a proper Exhaust Gas Temp gage if it is too lean then the engine heats up a lot and can damage internal parts.
So by enriching the gas mix does make the car run cooler and can be a good temporary fix while traveling.
Also anti freeze is an enemy of a non pressurized cooling system and you may have some snot in the tubes due to the anti freeze but it could be a volume issue as was stated by John/CT. Gary Bergbower in Southern Illinois makes a high volume radiator with flat tubes that cools better than any radiator we have tried or are aware of using.
I think that the flow rate of a good clean original radiator should be around 50-52 gal/minute. Post your results as always is interesting to find out the solutions to overheating problems.
In St Louis in 88 with temps over 100 degrees everyday we beat some of the impellers ears off so the water pumps didn't pump so much water but the bottom line was anti freeze snot in the tubes.
Good luck and look forward to having you join us in Branson Missouri next June.
Dan B

Phon, could you clarify your statement "anti freeze is an enemy of a non pressurized cooling system". How is/why is that?

[glenn in camino]

Originally Posted by Ed Saniewski

Going to and coming home from Gettysburg I had a problem with the engine overheating. We traveled 160 miles and a lot of it was at 45-50 MPH. I noticed that if I opened the GAV adjustment 3/4 to 1 full turn that the temp would come back down to normal, but when I came to a stop the engine would start to stall due to the rich mixture. Dose this mean that my main jet orifis is restricted or too small? Or is this just something I need to do when driving in hot weather. Thanks

My car also overheats in hot weather. I drive it with the front license plate up to allow more air to the radiator. This week I'm cleaning the radiator of grease
with Simple Green and then using Evaporust to dissolve the rust in the block.