'56 Country Sedan Overheating

tsanborn

Member
Well, this is disappointing. I had my '56 Country Sedan 292 Y-block rebuilt to resolve some blow-by issues. Once I got the car back, I added Vintage Air a/c. With the added load of the a/c, I upgraded the radiator to a Griffen rated for 500 hp. That has to be twice the output of the Country Sedan so I thought I'd be good. I also added a auxiliary pusher fan controlled by the trinary a/c system (as well as an under dash switch). Once I started driving the wagon, I started to experience overheating issues. I fabricated a radiator shroud and a 5 blade higher efficiency fan. I also removed the thermostat. Unfortunately, it hasn't solved the problem. Driving around town in light traffic with temperatures in the high 70s to low 80s, the engine temperature climbs above the gauge range and will continue to peg on hot if I don't shut it down. The auxiliary fan is triggered when the temperature gets to about 2/3 on the gauge and continues to run until it's turned off. The overheating occurs whether the a/c is on or off, although it occurs more rapidly with it on.

I have to believe the new oversized radiator is working so I'm not sure what's going on. I can take some temperature readings if it would help diagnose the problem. Hope someone out there has some ideas. It would be nice to solve this problem.

Tom
 
Does the coil spring of the thermostat point into the intake manifold?

Is the distributor original to '56? Is the ignition timing advance working?
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DMSFFR-

Thanks so much for your help. I decided to just leave the thermostat out to eliminate that as a possible problem. I will confirm that the vacuum advance is working. It probably doesn't matter but the wagon has a 3 speed manual.
 
If it has the original '55 / '56 style Loadomatic distributor, they are totally dependent on a matching vacuum signal from an original '55 / '56 carburetor for correct ignition timing advance.

If the points breaker plate in the distributor can't rotate slightly or isn't functioning due to a bad vac hose, leaking vacuum diaphragm, etc. the timing will not advance at all, causing the engine to run hot.
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Any possibility head gasket is on wrong?
tsanborn,
The head gaskets have a water passage at the rear and a squared off corner that shows at the top front on both sides after the engine is assembled.
 

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[ in the high 70s to low 80s, the engine temperature climbs above the gauge range and will continue to peg on hot if I don't shut it down. ]

Has it gotten hot enough to blow out antifreeze? You mentioned other overheating symptoms? What have you seen? I believe the 56 uses water temp gauge completely different sensor than the later models. Any chance the rebuilder installed a new (possibly incorrect) one? If you have a correctly matched 1956 sensor and gauge, the temp gauge needle should be at H when the key is off. When the key is turned on the
needle should move to the temp the engine is actually at.

Don
 
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My sincere thanks to dmsfrr, 58 Yeoman, Late Model, 5851a and of course, kultulz-

So many good questions. Here's what I know:

The radiator was filled with a surcharging funnel and the engine run with it in place so I believe there shouldn't be air pockets. I could see coolant circulating through the funnel when running.

The distributor is an aftermarket electronic unit. I can see the vacuum advance working when I suck on the vacuum line. I have to assume that the carb is doing it's job and that the rubber connector isn't leaking. Everything looks to be in good condition.

The temp gauge is original to the car. When power is off, it pegs on "H". When running, the gauge appears to operate normally.

The engine was overheating with the thermostat in place (and installed correctly I believe). I removed it to eliminate it as a possible problem. Once it's sorted out, I'll re-install a new one.

I can confirm that the auxiliary fan is pushing air when running (which it is whenever the engine gets hot).

Finally, I can clearly see that there is not any gasket material sticking out from the front corner of either head where it meets the block. Is it possible that my crack engine builders installed the head gaskets on backwards?

I wish I could attach photos of the engine to confirm that I'm looking at the right area of the head but it appears that I am roadkill on the informational superhighway. I have tried zipping the photos and sending them individually but I keep getting a message that I'm missing a "security token".
Oh well, fix the car first, learn to use the website next.

Thanks to all for your invaluable help,

No más, Tomás
 
I can see the tabs on the head gaskets, so they were assembled correctly.

You still have the LOAD-O-MATIC SYSTEM although with an electronic triggering device. It (triggering device) only replaces IGN POINTS and the LOM SYS is still operational. If it does not operate correctly, the timing will be retarded leading to overheating. That and reduced airflow through the RAD as you have both a pusher electric fan and AC COND in front of it.

Did it overheat before the rebuild?
 
tsanborn,
Photos 1, 2 & 3 below are zoomed in copies of your photos.
Yes, your distributor is an original style '56 Loadomatic for a 4bbl engine, with a points conversion module added.
Photo 1

Photos 2 and 3 show the 90 degree corner of your head gaskets, visible at the top front on both heads as they should be.

What carburetor does the engine have?.. IF, it's newer than an original '56 carb the timing advance is most likely not working right. See photo 4.

You may want to get a handheld infrared Temp gun to see how hot the thermostat housing, radiator, etc. are actually getting.
 

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DMSFRR had attached photos of head gasket showing how it should appear when installed correctly. As I understand it, I should see a small tab of gasket material sticking out beyond the radiused corner of the head and overlapping the block.

KULTULZ said; "I can see the tabs on the head gaskets, so they were assembled correctly." When I look at the closeup photos of my heads, I don't see those tabs. Am I looking at the wrong thing?

I believe the carb is original to the engine. It is a 4 barrel very tall configuration that I'm told was used on T-birds in 1956. I just had it rebuilt by someone who is very familiar with the these carbs. Is there a way to test vacuum produced by the carb. Could I just check the dwell with the engine running?

Finally, I never had overheating issues with the car prior the to the engine rebuilt (which makes me again wonder if the head gasket isn't blocking off coolant flow).
 
KULTULZ said;

I have to watch what I say as it can so easily be used in court against you ... :o

"I can see the tabs on the head gaskets, so they were assembled correctly." When I look at the closeup photos of my heads, I don't see those tabs. Am I looking at the wrong thing?

See how the front of the gasket(s) has a square tab? These indicate mounting direction, they always go UP towards the front of the engine (FYB).

The tab(s) will show in your ILL as a lighter pink in color ...

As mentioned, we really need photos of the radiator install. There are many reasons for one to overheat. Did you retain the ENGINE STEADY REST and BAFFLES?
 

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OK, I get it! I was misinterpreting my own photo. I thought the gasket tab was the corner of the block. Doh!

Here are some photos of the radiator. Mounted on the front of the radiator is the a/c condenser separated from the radiator by about an inch. In front of the condenser is a pusher auxiliary fan, also with a small space between them. I again confirmed that it is pushing a good deal of air through the radiator.

The overheating most often occurs when climbing up a moderate hill to our house. We haven't put many miles on the car since the rebuild, mostly about town so climbing the hill is the first load placed on the car after warming up. I'll take it for a extended spin on the freeway and see what we see. Hello Auto Club?

I added the overflow tank after getting tired of mopping up coolant from the garage floor after watching the temp gauge climb to hot. BTW, the auxiliary fan is only energized when the ignition is on so shutting down the engine once it's hot probably leads to increased coolant temperatures and boil-off.
 

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The 1st thing I see is your shroud prolly isn't doing much of anything. You need about 2/3 the width of the fan blades inside the shroud for best efficiency. The best shrouds are full coverage so the the fan pulls air through the entire core. The way it is now the fan is prolly recirculating hot air from the engine compartment through the rad core. Also, there should be a metal splash pan bolted to the front crossmember that extends back to just in front of the oil pan. The pan serves 2 purposes: it keeps spray from splashing up onto the front of the engine and also acts as sort of an air guide to reduce recirculation of hot air from the engine compartment through the radiator. I would also seal as many gaps/holes around the radiator as possible to force more air through the core.
 
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tsanborn,

This is a bit puzzling. You had an engine rebuilt that was not overheating, and added some modifications to reduce potential overheating, and now it overheats.
Dmsfrr’s suggestion of getting an infra red gun and measure temperatures is good advice. I believe that was what you were asking originally as to where to check temperatures. As he suggests, start at the thermostat area and water inlet on the radiator. If you can, get a temp at the radiator outlet at the bottom of the radiator. There should be 10 to 15F degree drop between inlet and outlet. Less than 5F indicates an airflow problem, usually not enough airflow, or possibly too fast of water flow caused by wrong pulley diameters, or no thermostat as KULTULZ mentioned.
If you can get your hands on an electronic thermometer with a couple of thermocouples you should also check the air temperature drop through the radiator. It should have about a 10F degree drop. Any less and you have an air flow problem.
I wouldn’t take the LoadaMatic system out of contention yet until the timing and advance are checked. I’m not sure that module and the LOM are compatible. Was it it used before the rebuild?
I have had overheat problems caused by the lack of an anti-vacuum spring in the lower radiator hose. If the big coil spring is missing, the hose will collapse from suction and slow or stop the water flow. Do you know that the spring is in there?

Don
 
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