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!

Re: Engine Cooling Question
 

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

Re: Engine Cooling Question
 

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

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.

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???

Re: Engine Cooling Question
 

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.

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.

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

Re: Engine Cooling Question
 

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.

Re: Engine Cooling Question
 

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

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.

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

Re: Engine Cooling Question
 

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

Re: Engine Cooling Question
 

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

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.