Overheating

A

arefftx

Member
Took my '29 Roadster out today for a longer than normal outing, about 5 miles...she performed very well even got her up to about 45 mph. Last fall I had the radiator rebuilt so what happened today? she overheated and blew foaming coolant out of the radiator cap. I took her home and she cooled down quickly but wonder what might be the cause?.......this is an issue! was the radiator overfilled??
 
If the timing was not advanced enough it can overheat. The water that expands from overfilling should exit via the overflow pipe to the ground.
 
Number one, the cap should be sealed, you can get an O ring at the hardware store that'll do that. Number two, run the timing just less than ping on acceleration. Number three, let the radiator find its level, as long as it is over the tubes in the radiator it'll be fine. Number four, coolant shouldn't be foaming. Flush it out well, then fill with regular green antifreeze 50/50 mix. Also, "you got it up to 45mph", that isn't a great feat if everything is as it should be. 45 to 50 is comfortable cruising speed if the car is "right". Don't settle for less than reliable and safe condition. Fix what needs to be fixed until it is. And last but certainly not least, have a ton of fun!
 
eagle said:
Number one, the cap should be sealed, you can get an O ring at the hardware store that'll do that. Number two, run the timing just less than ping on acceleration. Number three, let the radiator find its level, as long as it is over the tubes in the radiator it'll be fine. Number four, coolant shouldn't be foaming. Flush it out well, then fill with regular green antifreeze 50/50 mix. Also, "you got it up to 45mph", that isn't a great feat if everything is as it should be. 45 to 50 is comfortable cruising speed if the car is "right". Don't settle for less than reliable and safe condition. Fix what needs to be fixed until it is. And last but certainly not least, have a ton of fun!
Click to expand...

Do not use an antifreeze with glycol in it if the radiator is soldered. The glycol eats solder.
I do not cruise at anything over about 42mph even though the car seems happy at 50. I've seen too many middle main bearings fail because of the high speed. We ask too much of these old cars. Remember, the beat of road in the late 20s in the US had a speed limit of 40 mph.
 
Thanks for all the suggestions I check the O ring & the antifreeze I am using. The timing sounds like the main reason!
Speed is not important problem free from being is the goal.!
 
arefftx said:
Thanks for all the suggestions I check the O ring & the antifreeze I am using. The timing sounds like the main reason!
Speed is not important problem free from being is the goal.!
Click to expand...
I set my timing lever by listening to the engine. Advance it until you just start to hear it ping on hard acceleration, then back off a click. Engine will have good power at that point but will run cool. Learn what ping sounds like. If you can't hear good enough, teach a grandkid what it should sound like and take them with you on a run or two until you get it figured out. Its a very distictive sound, anyone with reasonably good hearing will be able to detect it. As we get older the higher frequencies are harder for us to hear, so I suppose I'll lose that ability someday as well. I heard of someone who set up an electronic ping detector, not sure how they did it but that could be a hot selling accessory for a model A if someone started manufacturing them.
 
Eagle:
Great information, I'll try it out this evening......FYI I know your part of the world, my ex-wife & mother of my children is originally from Bertha.

Alan
 
Alan you need to know for sure if your engine is overheating or not. Get a cheap dial meat thermometer and place it directly into the coolant to get a temperature reading.
 

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If you cannot hear the ping you can set the timing by the knee. That is where the engine power will drop off if you retard the ignition one click but will not improve if you advance the ignition one click. The timing should be adjusted depending on conditions such as load, rpm, and other factors. Running the car up a grade will require retarding the ignition slightly, one click or two. Get in the habit of continuously adjusting the timing depending on conditions.
 
Katy brought up a good point. Do you have thermostat? For summer driving I take mine out or drill more holes in the flange.
 
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