Cooling problem

C

cavecreekjake

Member
Have a frustrating cooling issue - 276 ci Walt Dupont 8BA block, Navarro early heads (center hose), 20 quart Custom Auto radiator (7 row), 2000cfm fan. Had a problem with temp going quickly to 220 on startup, but would go down to 180 on the highway.
Suspected a head gasket leak might contribute to quick temp rise, and sealing up when expanded at temp(coolant also 'dirty', like maybe exhaust leaking into it). So, changed head gaskets (to match heads), installed Skip's pumps, had radiator flushed.... Now it warms slowly, but now goes to 195-200 on the road, and 220 in traffic. Won't come back to 180 on the road. Using Evans Waterless Coolant, so doesn't boil over, but not comfortable with it running that hot. And that's on 75 degree days. Don't know yet what it will do on a really hot day. Have checked timing (4 degrees @ idle, 22 degrees advanced), and plugs suggest not running lean. Have tried both with & without thermostats.
At a loss as to what else to try....
???
Thanks for any suggestions
 
I had 53 Victoria ran hot, tried everything new pumps, new 3 row radiator, used chemical to remove rust in engine, electric fan and shroud, used 7 lb pressure cap, installed antifreeze claims wont boil till 240 deg, installed a/c, engine ran great at 200 deg in city, highway would heat 230 deg this is on 90 deg day, removed electric fan and shroud, installed 6 blade fan blade, ran 200 deg highway, 210 city, did not boil. the electric fan and shroud would not let enough air to pass through radiator on highway, that's the best I could get, I didn't like it running that hot.
 
image.jpg

Model A hot rod, fan is a Speedway 16" curved bade 2100 CFM, running as a 'puller'...
 
First... is this a heating problem (timing, fuel mix, compression) or a cooling problem (pumps, radiator, water flow).

Second... is this a high speed issue, slow speed issue, an issue with both.

For testing, figure a way to install sending units and gauges in each of the inlets and outlets, you should show good cooling of the radiator. Mismatched readings on one side could clue you in to a heating problem or a water circulation problem. Too hot in - cool out is a motor/circulation problem. Too hot in - too hot out is a cooling problem, the radiator is not sufficient or the air flow is wrong.

You did not say what the car is... does it have all the stock aprons around the grille. If its a 1940 it will need a blocking plate between the grille and hood to prevent cool air from going over, also 1940 needs the stock braces behind the front fender, they help with extracting air from the engine compartment.

Do you have thermostats? Test them. A rare problem is that a thermostat will prevent water from moving, yet will be placed where it does not get heat to open before the motor gets too hot. A thermostat with a "pee" hole will fix this (experience, Zips high riser pump on SB Chev).

Have fun
 
FWIW, never had any luck with an electric fan as a primary. Large percentage of the time overheating problems are the fault of air flow through the radiator. Put a 302 in a Bronco II and tried an electric fan as there wasn't room to put a regular fan on it. No luck. Moved the radiator forward and installed a 6 blade engine driven fan and a shroud. Problem solved.
 
Last edited:
One thing is when you have a 7row its hard for the air to go through and if it has very fine tubes the flatheads pumps don´t put out very much pressure.
So 2 not very good things...restricted flow for both air and coolant.
My bet is less rows with a bit bigger tubes in it would be better for a flathead...
 
The temperatures on the goose neck covers are the temperatures of
the HOT water coming out of the engine. Hold the heat gun the same
distance, same angle and hit the same spot every time you take a
temperature. This is the best readings you can get. G.M.
 
Don't have goose neck covers.... 8BA block, but 59AB style center outlet Navarro heads.
Guess I could try taking the reading on the head outlet right next to the hose, or maybe better still, the chrome pipes between the head and radiator.
 
If its going to 220 in traffic on switching the fan on it should pull temperature down .I would say the real condition of your Radiator is un known flushing is not good enough A vinegar soak or remove the tank and rod it out .or replace it with new,Ted
 
Last edited:
Flushing radiator wont cure a build up in cores. I opened mine and found nearly no passage. I say: New or recored radiator.

Good luck. Christian, Denmark
 
cavecreekjake said:
Don't have goose neck covers.... 8BA block, but 59AB style center outlet Navarro heads.
Guess I could try taking the reading on the head outlet right next to the hose, or maybe better still, the chrome pipes between the head and radiator.
Click to expand...

On the metal part of the heads just below the hoses. G.M.
 
If it´s a 7 row radiator as stated in first post...normal is 2-3rows thats a difficult radiator to get the air flowing good through...takes a good fan and tight shroud.
Then if its 7 rows it must have very thin tubes that takes a lot of pressure to move water through...and flathead pumps don´t put out high pressure.
So if above is right my bet still is on a "less good" normal radiator.
Its not like you need to cool 1000HP so no need for a monster radiator.
 
Cave - like your car.
New or a swap meet find? 7 row radiator ? Is it a high efficiency? Flatheads do not work well with that type of radiator. US Radiator makes a nice 'high efficiency' core, which I used. Engine was in the 200+ range. Went to their OEM style and all is good. It is on my stock 49.
Did you test for exhaust in the coolant? Best way is to use an exhaust gas probe. Find some independent auto repair shop. Rev the engine slowly open the radiator cap and place the probe into the next area of the radiator. See how many PPM of CO2 if it is in the 20 range, you have a leak. Should be in the 5 or less range. I've used the fluid test you can get from NAPA, and have had mixed results.
Try running without the thermostats. You might have a 'stat turned over in the head / hose connection.
What distributor are you running with that triple carb setup? Not the stock one for 3 carbs.
 
Last edited:
You must log in or register to reply here.
Back
Top