The Ford Barn

My3window · 07-21-2015, 04:43 PM

I have a 34 coupe with a rebuilt 34 engine, re-cored radiator, and rebuilt water pumps. Currently, I do not have the hood installed on the car. While stationary in my driveway, the engine will idle for about ten minutes but then it begins to overheat. I have been waiting to install the front fenders, grill and hood assembly until I know the car is ready for that part of the restoration. Can anyone tell me if having the hood installed around the motor will help or worsen the heating issue I am having? I have read that installing the lower pan that fits below and in front of the grill helps direct air through the radiator when the car is moving.

Thanks for your input!

toby · 07-21-2015, 04:52 PM

How is it overheating? Water out the radiator? Stock temp gauge reading hot?

51 MERC-CT · 07-21-2015, 05:08 PM

" Begins to overheat " What does that mean? Rise in temp would be normal.

deuce_roadster · 07-21-2015, 05:29 PM

Have you re-torqued the heads? It is important, especially with aluminum heads. I usually do 3 heat/cold/re-torque cycles right after firing it for the first time.
And as others have asked, is it boiling over or what? You need some room for expansion of the water when it gets hot so fill to just a bit over the tubes.

My3window · 07-21-2015, 05:49 PM

Sorry, should have been more specific. I have a 34 dual temp gauge and the level on the gauge gradually climbs above the "Normal" range to the "Hot" line after 8 -10 minutes. When the gauge reaches "Hot", steam begins to come out the top of the radiator.

I've tried starting the motor a few times now and I've been shutting it down when the engine gets this hot. Also, I have added coolant to the water and I've just recently removed the 170 degree thermostats that were in both upper radiator hoses. I checked the thermostats and they both opened correctly at the indicated temperature, however when the thermostats were open, it seemed like they were still not opening enough to provide adequate flow. Removing the thermostats has helped but has not solved the problem. It was suggested to me that putting the hood on may keep the motor cooler???

Drbrown · 07-21-2015, 05:50 PM

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deuce_roadster makes an important point .... water level when cold should be about 2 inches below cap; enough to cover the radiator cores. Otherwise it usually spits it out over a number of runs.

My3window · 07-21-2015, 06:30 PM

Most recent test. I started the motor again a few minutes ago. This time I did not let it steam. The motor ran 12 minutes idling before the gauge registered hot. At this point a fluid began dripping out of my radiator over flow tube about one drip every 10 seconds. Again I shut it down. Going back to my original question, is 10 minutes of idling time acceptable for a rebuilt motor? And, if I re-assemble the sheet metal (hood, engine pans, radiator pan, fenders, etc, will enclosing the motor cause it to get hotter quicker.

V8COOPMAN · 07-21-2015, 06:58 PM

Honestly, no one can reasonably or accurately predict or guarantee your results once you enclose the engine with the factory sheetmetal. But keep one very important fact in mind........ANY heated air that is drawn into the engine compartment (from the radiator) by the fan, MUST be able to exit the engine compartment.......heated air must be dissipated.

There are all sorts of reasons your engine MAY be overheating under the idling circumstances, but one very important item to check is the distributor timing. If the timing is RETARDED from optimum to any degree, the engine will easily run hotter than normal. One more thing........it's not generally a very good idea at all to idle a "new" engine with no load on it for any length of time. Check that timing! DD

G.M. · 07-21-2015, 07:02 PM

Quote:

Originally Posted by My3window

Most recent test. I started the motor again a few minutes ago. This time I did not let it steam. The motor ran 12 minutes idling before the gauge registered hot. At this point a fluid began dripping out of my radiator over flow tube about one drip every 10 seconds. Again I shut it down. Going back to my original question, is 10 minutes of idling time acceptable for a rebuilt motor? And, if I re-assemble the sheet metal (hood, engine pans, radiator pan, fenders, etc, will enclosing the motor cause it to get hotter quicker.

Go back and look up several recent posts I responded to. These explain how the cooling system works and things to improve cooling such as stopping the lose of coolant from the over flow tube. G.M.

JSeery · 07-21-2015, 07:14 PM

Keep idling a newly rebuilt engine and overheating may be the least of your concerns!

woodiewagon46 · 07-21-2015, 07:22 PM

The hood and engine pans all play a part in cooling. I had first hand experience with a '37 Ford. It was mildly hopped up and the owner decided to remove the hood. Once the hood was removed the car ran hot. What he found out was that when the air hit the firewall it created a positive pressure in the engine compartment, not allowing enough air thru the radiator. He put the hood back on and the car runs great. I would think in your case the fan isn't pulling enough air thru the radiator with out the hood. Any way you can temporarily install it.

Brian · 07-21-2015, 07:38 PM

J Seery's advise is what first came to my mind. But too late...you've probably already glazed your cyl walls. Best thing you could do now is get in it and drive the *rap outta it, and hope you can seat those rings. Good luck

46ford · 07-21-2015, 07:55 PM

When this happened to me, my timing was retarded badly. Check your timing!

Kurt in NJ · 07-21-2015, 08:34 PM

Exhaust plugged up with mouse /chipmonk nest and food will cause overheating too

expavr · 07-21-2015, 08:57 PM

Regarding your original question whether or not to install the hood, fenders and other sheet metal it would be prudent to resolve the heating issue before putting all that iron back on simply from the point of view that its much easier to access the engine and radiator without them. Regarding the hood and its impact on heating I drove the tonner for about 80 miles with no hood or fenders while breaking in the engine and had no over heating issues whatsoever. I did install the shroud on the radiator which might have helped cooling at slower driving speeds, but based on my experience I don't see that you'll gain much if any benefit from installing the hood and fenders. Keep in mind that these engines were used in many stationary applications where the only concession to air flow through the radiator was a shroud - no hood, fenders or chin deflectors.

07-21-2015, 04:43 PM	#1
My3window Senior Member Join Date: Apr 2012 Location: Saint Helena, California Posts: 252	Engine Cooling Question I have a 34 coupe with a rebuilt 34 engine, re-cored radiator, and rebuilt water pumps. Currently, I do not have the hood installed on the car. While stationary in my driveway, the engine will idle for about ten minutes but then it begins to overheat. I have been waiting to install the front fenders, grill and hood assembly until I know the car is ready for that part of the restoration. Can anyone tell me if having the hood installed around the motor will help or worsen the heating issue I am having? I have read that installing the lower pan that fits below and in front of the grill helps direct air through the radiator when the car is moving. Thanks for your input!

07-21-2015, 04:52 PM	#2
toby Senior Member Join Date: May 2010 Location: Racine, WI Posts: 472	Re: Engine Cooling Question How is it overheating? Water out the radiator? Stock temp gauge reading hot?

07-21-2015, 05:08 PM	#3
51 MERC-CT Senior Member Join Date: May 2010 Location: East Hartford, Ct Posts: 5,898	Re: Engine Cooling Question " Begins to overheat " What does that mean? Rise in temp would be normal. __________________ DON'T RECALL DOING SOMETHING FOR MYSELF BASED ON SOMEONE ELSE'S LIKES OR DISLIKES

07-21-2015, 05:29 PM	#4
deuce_roadster Senior Member Join Date: Oct 2011 Location: Shelton, WA Posts: 3,800	Re: Engine Cooling Question Have you re-torqued the heads? It is important, especially with aluminum heads. I usually do 3 heat/cold/re-torque cycles right after firing it for the first time. And as others have asked, is it boiling over or what? You need some room for expansion of the water when it gets hot so fill to just a bit over the tubes.

07-21-2015, 05:49 PM	#5
My3window Senior Member Join Date: Apr 2012 Location: Saint Helena, California Posts: 252	Re: Engine Cooling Question Sorry, should have been more specific. I have a 34 dual temp gauge and the level on the gauge gradually climbs above the "Normal" range to the "Hot" line after 8 -10 minutes. When the gauge reaches "Hot", steam begins to come out the top of the radiator. I've tried starting the motor a few times now and I've been shutting it down when the engine gets this hot. Also, I have added coolant to the water and I've just recently removed the 170 degree thermostats that were in both upper radiator hoses. I checked the thermostats and they both opened correctly at the indicated temperature, however when the thermostats were open, it seemed like they were still not opening enough to provide adequate flow. Removing the thermostats has helped but has not solved the problem. It was suggested to me that putting the hood on may keep the motor cooler???

07-21-2015, 05:50 PM	#6
Drbrown Senior Member Join Date: Oct 2013 Location: Glens Falls NY Posts: 1,267	Re: Engine Cooling Question Sponsored Links (Register now to hide all advertisements) deuce_roadster makes an important point .... water level when cold should be about 2 inches below cap; enough to cover the radiator cores. Otherwise it usually spits it out over a number of runs.

07-21-2015, 06:30 PM	#7
My3window Senior Member Join Date: Apr 2012 Location: Saint Helena, California Posts: 252	Re: Engine Cooling Question Most recent test. I started the motor again a few minutes ago. This time I did not let it steam. The motor ran 12 minutes idling before the gauge registered hot. At this point a fluid began dripping out of my radiator over flow tube about one drip every 10 seconds. Again I shut it down. Going back to my original question, is 10 minutes of idling time acceptable for a rebuilt motor? And, if I re-assemble the sheet metal (hood, engine pans, radiator pan, fenders, etc, will enclosing the motor cause it to get hotter quicker.

07-21-2015, 06:58 PM	#8
V8COOPMAN Senior Member Join Date: May 2010 Location: East Shore of LAKE HOUSTON Posts: 11,113	Re: Engine Cooling Question Honestly, no one can reasonably or accurately predict or guarantee your results once you enclose the engine with the factory sheetmetal. But keep one very important fact in mind........ANY heated air that is drawn into the engine compartment (from the radiator) by the fan, MUST be able to exit the engine compartment.......heated air must be dissipated. There are all sorts of reasons your engine MAY be overheating under the idling circumstances, but one very important item to check is the distributor timing. If the timing is RETARDED from optimum to any degree, the engine will easily run hotter than normal. One more thing........it's not generally a very good idea at all to idle a "new" engine with no load on it for any length of time. Check that timing! DD __________________ *Click Links Below* __ ▼ *'35-'36 W/8BA & MECHANICAL FAN* *T5 W/TORQUE TUBE* Last edited by V8COOPMAN; 07-21-2015 at 07:10 PM.

07-21-2015, 07:14 PM	#10
JSeery Member Emeritus Join Date: Nov 2012 Location: Wichita KS Posts: 16,132	Re: Engine Cooling Question Keep idling a newly rebuilt engine and overheating may be the least of your concerns!

07-21-2015, 07:22 PM	#11
woodiewagon46 Senior Member Join Date: Jun 2012 Location: Long Island,NY Posts: 1,555	Re: Engine Cooling Question The hood and engine pans all play a part in cooling. I had first hand experience with a '37 Ford. It was mildly hopped up and the owner decided to remove the hood. Once the hood was removed the car ran hot. What he found out was that when the air hit the firewall it created a positive pressure in the engine compartment, not allowing enough air thru the radiator. He put the hood back on and the car runs great. I would think in your case the fan isn't pulling enough air thru the radiator with out the hood. Any way you can temporarily install it.

07-21-2015, 07:38 PM	#12
Brian Senior Member Join Date: May 2010 Location: Masterton, New Zealand Posts: 3,834	Re: Engine Cooling Question J Seery's advise is what first came to my mind. But too late...you've probably already glazed your cyl walls. Best thing you could do now is get in it and drive the *rap outta it, and hope you can seat those rings. Good luck __________________ Unfortunately, two half wits don't make a whole wit!

07-21-2015, 07:55 PM	#13
46ford Senior Member Join Date: Nov 2010 Location: Nottawa MI Posts: 289	Re: Engine Cooling Question When this happened to me, my timing was retarded badly. Check your timing!

07-21-2015, 08:34 PM	#14
Kurt in NJ Senior Member Join Date: May 2010 Location: on the Littlefield Posts: 6,159	Re: Engine Cooling Question Exhaust plugged up with mouse /chipmonk nest and food will cause overheating too

07-21-2015, 08:57 PM	#15
expavr Senior Member Join Date: May 2010 Location: Hansville, WA Posts: 776	Re: Engine Cooling Question Regarding your original question whether or not to install the hood, fenders and other sheet metal it would be prudent to resolve the heating issue before putting all that iron back on simply from the point of view that its much easier to access the engine and radiator without them. Regarding the hood and its impact on heating I drove the tonner for about 80 miles with no hood or fenders while breaking in the engine and had no over heating issues whatsoever. I did install the shroud on the radiator which might have helped cooling at slower driving speeds, but based on my experience I don't see that you'll gain much if any benefit from installing the hood and fenders. Keep in mind that these engines were used in many stationary applications where the only concession to air flow through the radiator was a shroud - no hood, fenders or chin deflectors.