The Ford Barn

rfequity · 07-11-2021, 07:05 PM

Is it normal after an in town drive that the top of the shroud around the cap would be too hot to touch? Its in the 80’s outside and very humid. Also, i notice the engine seems alot more sluggish when its humid.

WHN · 07-11-2021, 07:14 PM

I’ve never had it that hot. Just warm to the touch.

ETAModel · 07-11-2021, 07:19 PM

Hot to the touch is a relative term. A friend worked in a dental lab making teeth and he can hold a fresh cast lead bullet.

The cap on the 30 fordor i drive gets pretty warm, almost too warm to handle, but idk how hot that is.
Don't they call the model A "Hotwater Fords"?

1crosscut · 07-11-2021, 09:09 PM

Use a deal meat thermometer placed into the coolant to check the temperature.

1931 flamingo · 07-12-2021, 08:24 AM

Get a "point and shoot" temp gun at Harbor Freight and get back to us.
Paul in CT

Richard in Anaheim CA · 07-12-2021, 08:07 PM

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It's unlikely you actually mean shroud. They only came on '28 and were usually thrown away with the engine pans. Do you actually mean radiator cap, top tank of the radiator, or radiator shell?

The radiator is intended to dissipate heat. Do you usually just drive to the 7-11 and home and this time actually put 10 or 15 miles on it? It will be too hot to touch, probably 140-170 degrees.

rfequity · 07-12-2021, 08:31 PM

Yes, i meant the “shell”.

abachman3 · 07-12-2021, 09:24 PM

The top of the radiator shell is being heated by radiant heat dissipating from the radiator. When the engine is turned off, the engine generally gets warmer as does the radiator, as there is no more cooling happening through the radiator. So, yes I would say, even from personal experience, that the top of the shell does get quite hot. I have never checked the actual temperature, but know that mine will get too hot to keep your hand on it.

1928Mik · 07-13-2021, 07:41 AM

I'm with abachman3. Once you shut down, the top of the shell will normally get hotter for a bit...

rfequity · 07-13-2021, 09:52 AM

Thank you all. That all makes sense. Thanks again for the help.

WHN · 07-13-2021, 11:19 AM

The thermo syphon continues with the engine not running. Unlike a more modern car, the water pump is just there for added help with the engine cooling. Modern cars have the water pump installed at the inlet to the engine. Forcing the coolant into your motor. Model A’s pump is mounted at the outlet of the engine. As your Model A engine warms up, the coolant starts moving out and into the radiator. Thermo Syphon. Cools down, sinking to the bottom of radiator and back into the engine. Pushing the warmer water up and out the top of your engine. I think what you are seeing happen when the engine is shut off is the now lack of air moving over and around you radiator and engine. Engine fan is no longer turning and the air from your car moving forward is not going thru the radiator.

Syphon should still be working trying to cool the system. I would think that to hot to touch might indicate a cooling problem.

katy · 07-13-2021, 11:22 AM

As long as it's not boiling.

07-11-2021, 07:05 PM	#1
rfequity Junior Member Join Date: Jun 2021 Posts: 25	top of radiator shroud hot Is it normal after an in town drive that the top of the shroud around the cap would be too hot to touch? Its in the 80’s outside and very humid. Also, i notice the engine seems alot more sluggish when its humid.

07-11-2021, 07:14 PM	#2
WHN Senior Member Join Date: Mar 2017 Location: Connecticut Shoreline Posts: 1,823	Re: top of radiator shroud hot I’ve never had it that hot. Just warm to the touch.

07-11-2021, 07:19 PM	#3
ETAModel Senior Member Join Date: May 2013 Location: Along the Red River, Texas Posts: 360	Re: top of radiator shroud hot Hot to the touch is a relative term. A friend worked in a dental lab making teeth and he can hold a fresh cast lead bullet. The cap on the 30 fordor i drive gets pretty warm, almost too warm to handle, but idk how hot that is. Don't they call the model A "Hotwater Fords"?

07-12-2021, 08:24 AM	#5
1931 flamingo Senior Member Join Date: May 2010 Location: new britain,ct 06052 Posts: 9,390	Re: top of radiator shroud hot Get a "point and shoot" temp gun at Harbor Freight and get back to us. Paul in CT

07-12-2021, 08:07 PM	#6
Richard in Anaheim CA Senior Member Join Date: May 2010 Location: Anaheim California Posts: 551	Re: top of radiator shroud hot Sponsored Links (Register now to hide all advertisements) It's unlikely you actually mean shroud. They only came on '28 and were usually thrown away with the engine pans. Do you actually mean radiator cap, top tank of the radiator, or radiator shell? The radiator is intended to dissipate heat. Do you usually just drive to the 7-11 and home and this time actually put 10 or 15 miles on it? It will be too hot to touch, probably 140-170 degrees.

07-12-2021, 08:31 PM	#7
rfequity Junior Member Join Date: Jun 2021 Posts: 25	Re: top of radiator shroud hot Yes, i meant the “shell”.

07-12-2021, 09:24 PM	#8
abachman3 Senior Member Join Date: Jun 2013 Location: Western Springs, IL Posts: 324	Re: top of radiator shroud hot The top of the radiator shell is being heated by radiant heat dissipating from the radiator. When the engine is turned off, the engine generally gets warmer as does the radiator, as there is no more cooling happening through the radiator. So, yes I would say, even from personal experience, that the top of the shell does get quite hot. I have never checked the actual temperature, but know that mine will get too hot to keep your hand on it.

07-13-2021, 07:41 AM	#9
1928Mik Senior Member Join Date: Feb 2017 Location: Zanesville Ohio USA Posts: 268	Re: top of radiator shroud hot I'm with abachman3. Once you shut down, the top of the shell will normally get hotter for a bit... __________________ 1928 Niagara Blue Phaeton 1972 Olds 442 Convertible 1979 MGB -Life's Too Short To Drive Boring Cars-

07-13-2021, 09:52 AM	#10
rfequity Junior Member Join Date: Jun 2021 Posts: 25	Re: top of radiator shroud hot Thank you all. That all makes sense. Thanks again for the help.

07-13-2021, 11:19 AM	#11
WHN Senior Member Join Date: Mar 2017 Location: Connecticut Shoreline Posts: 1,823	Re: top of radiator shroud hot The thermo syphon continues with the engine not running. Unlike a more modern car, the water pump is just there for added help with the engine cooling. Modern cars have the water pump installed at the inlet to the engine. Forcing the coolant into your motor. Model A’s pump is mounted at the outlet of the engine. As your Model A engine warms up, the coolant starts moving out and into the radiator. Thermo Syphon. Cools down, sinking to the bottom of radiator and back into the engine. Pushing the warmer water up and out the top of your engine. I think what you are seeing happen when the engine is shut off is the now lack of air moving over and around you radiator and engine. Engine fan is no longer turning and the air from your car moving forward is not going thru the radiator. Syphon should still be working trying to cool the system. I would think that to hot to touch might indicate a cooling problem.

07-13-2021, 11:22 AM	#12
katy Senior Member Join Date: Jun 2015 Location: Red Deer, Alberta Posts: 5,044	Re: top of radiator shroud hot As long as it's not boiling. __________________ If you don't hear a rumor by 10 AM, start one!. Got my education out behind the barn!