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EFV-8 Club Forum / General Ford Discussion / 40 cooling temp

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Posted By Discussion Topic: 40 cooling temp -- page: 1 2 3 4 5     Dons40 06-01-2016 @ 3:16 PM reply profile send p.m. Member Posts: 23 Joined: Jan 2016 Can anyone tell me the "correct" thermostat temp for a stock 40? Can you also enlighten with the correct pressure (Lbs) for the cap. The 40 I just bought had no thermostats whatsoever. Overheating challenges.... len47merc 06-01-2016 @ 4:12 PM reply profile send p.m. Senior Posts: 1165 Joined: Oct 2013 Technically 'correct' meaning original? Or 'correct' meaning most effective for your local climate? As I recall Mike Kubarth places 155s in all his '40s. Others in mostly northern climates run 177s-185s. Fwiw, worst case here in central NC, I run 177s in winter and 155s in summer only for the added heat during the winter - the vehicle runs the same approximate highest temp at highway speeds winter or summer regardless of stat rating. It simply warms up more quickly in the winter with the 177s. For the past two years I've run 177s only - winter & summer - never seen actual temps measured with a calibrated Fluke meter thermocouple exceed 195 in the hottest of summer runs at speed or during stop-n-go July 4 parades. Typical temps in the summer run 185-195, winter at speed 170-180 depending upon ambient temps. I run a 4# cap on the '47, but without the EFV8 book on '40s I am not aware what is technically correct for that year in this regard. Reach out to Mike Kubarth (kubes40). If you are having overheating challenges recommend you look first to a clean, free running radiator (versus the obvious) and whether the block is free and clear of debris, mold sand, etc.. Typically have not seen properly operating stats and stat temperature ratings, or no stats at all, as well as pressurized caps or not being the fundamental root causes of overheating issues. Steve This message was edited by len47merc on 6-1-16 @ 4:40 PM 40 Coupe 06-02-2016 @ 4:44 AM reply profile send p.m. Senior Posts: 1649 Joined: Oct 2009 Ford did not use a pressurized radiator cap in 1940 or 32 thru pre war. I used to run a 3# cap and found with use the top of the 40 radiator would bulge outward and would not return to the proper shape after cooling. The top tank is very large and easy to distort, especially over time and with some minimal pressure. The Ford procedure for correcting over heating has some basic steps before removing the radiator, the procedure is below. The procedure below could have a couple of additional steps added at the end. Have the water pumps rebuilt so they have better water flow. Make sure there is not a leaking head gasket (do a compression check and check spark plugs also look for exhaust gas bubbles in the coolant). Remove the engine heads and replace the head gaskets, make sure they are on properly with the small coolant holes toward the front of the engine block and larger holes in the rear. The last step would be to remove the oil pan and the welsh plugs in the engine block oil pan rail. dig out foundry sand at the rear plugs and flush out especially the rear of the block with clean water. There is usually a lot of sand left from the manufacturing process. The sand does NOT usually cause overheating but can cause some hot spots in the engine block. Good Luck 40 Coupe 06-02-2016 @ 4:46 AM reply profile send p.m. Senior Posts: 1649 Joined: Oct 2009 Second and final page of coolant Doc. kubes40 06-02-2016 @ 5:52 AM reply profile send p.m. Senior Posts: 3371 Joined: Oct 2009 Steve has offered wonderful advice. 155° was in fact the stock thermostats from the factory. I use them in my restorations and have found they maintain each & every car at a good - operable temperature. Keep in mind though, my restorations include proper rebuilding of all components. The engines are boiled out, the radiators re-cored, distributors and carburetors properly rebuilt. If everything is rebuilt properly there is no need for high volume pumps and certainly no need for over flow tanks, check valves, etc. While those things may aid "what ails ya" they are no more than bandages applied in an attempt to mask the true underlying issue(s). TomO 06-02-2016 @ 7:22 AM reply profile send p.m. Senior Posts: 7244 Joined: Oct 2009 Don, The advice given above is the best way to solve overheating problems. If you provide more details about your overheating, we may be able to shorten the check list. Is the radiator boiling over or is it just the temperature gauge reading in the HOT range? Are you losing coolant? Does it happen when you are on the highway or just when you are in traffic? Tom Dons40 06-06-2016 @ 7:22 AM reply profile send p.m. Member Posts: 23 Joined: Jan 2016 Thanks to all for the input. First time "Forum" user and I can definitely see its a great way to tap into the knowledge base for these Early V8's. Here is where I'm at. All hoses replaced and leek proofed. Radiator filled with EG/Water mix. No thermostats. Radiator fins cleaned, radiator inspected and looks fine. With the cap off and engine running fast idle I can see good flow returning to the top of radiator from both upper hoses ( Good flow) Internals of radiator also look fine. Lets talk temp gauge. With ignition on, I have power to the gauge from the Ign switch and 6 Volt across the gauge. In addition, 6 volt out to the sending unit. Maybe someone can explain the circuit to me, as I'm a little unsure how it works. In any case, temp needle never comes off H. reading the bulletin, it implies the gauge needle rests with ign off on H. Once Ign is turned on ( engine cold) the needle should go cold and gradually rise as engine warms. Is this correct description, and if so is the gauge "bad"? New sending unit installed an makes no difference. Checked new and old sending units in warm water, and they Ohm out differently...? TomO 06-06-2016 @ 8:08 AM reply profile send p.m. Senior Posts: 7244 Joined: Oct 2009 The gauge and sending unit use a current balance to sense the temperature. Both the gauge and the sending unit with one terminal have bi-metal strips with heating coils. The bi-metal strips open and close the circuit in the sending unit. When the engine is cold, this action takes place less often and increases as the temperature rises. If you have a sending unit with 2 terminals, it is just an open and close switch. When the temperature increases beyond the boiling point the contacts open. To test the gauge, connect the wire from the gauge to the sending uni to ground for a few seconds, with the ignition on. The needle on the gauge should move toward ground. If it does not, either the wire is broken or the gauge is bad. Recheck with a jumper wire from the gauge to ground, to isolate the wire. Do not use teflon tape on the sending units threads. They need to make a good ground to the heads. The motor should have a ground strap from the body to a bolt on the intake manifolds. Tom Dons40 06-08-2016 @ 2:14 PM reply profile send p.m. Member Posts: 23 Joined: Jan 2016 Back in the shop last night. Temp sending unit is single post. Engine was not running. I pulsed the Ignition in both cases described below. . When I grounded the sending unit, gauge in dash went to C. went under dash, again ran a jumped from Gauge to ground , pulsed the Ignition switch, gauge did not move. Bad gauge? BTW that process of grounding the gauge yields a warm jumper is pretty short order! I realize the car is + ground so my terminology may not be "correct" If the gauge is shot, where can I find one? anyone know? 40cpe 06-08-2016 @ 4:21 PM reply profile send p.m. Member Posts: 472 Joined: Jan 2010 It sounds like when you tested the gauge under the dash you put the jumper on the feed, or hot, wire to the gauge. It should be placed on the other terminal. From your description, I think the sending unit is bad or not grounded to the engine properly. I don't understand the term "pulsed the ignition".

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