Overheating

41Fordor

41Fordor

Senior Member
I've read all the threads on overheating and still having problems. I have my original 1941 221 with sleeves removed and bored out to 239 standard which shouldn't be too thin from all I've read. I have Skip's water pumps and he rebuilt my helmet distributor. Mt radiator has been recored and running Gadgiteers thermostats and 4# cap. I installed springs in the lower hoses to keep them from collapsing. It overheats even without thermostats, and overheats at highway speed when plenty of air is moving through the radiator. I have a LZ 94 and jetted up to 51 which should be pretty rich for 6000' ASL.

I pulled the upper hoses and filled up the heads to the outlet to do a leakdown check. I applied 90 psi to all the cylinders one at a time with no bubbling. I can't remember what type of head gasket I used. I had a FelPro master set with 21 stud head gaskets, so my machinist ordered the head gaskets separately and I can't remember if they have round or trapezoidal holes.

I have my timing advanced as far as it will go (up to the top mark) and the vacuum brake backed out all the way. I have no detonation or ping at full advance. I wonder if either I installed the cam gear a tooth off; or the adapter button could be seated incorrectly?

After a 15 minute run at 55 mph today in 80 degree weather my water outlets were at 210-215* with an infrared thermometer. I have a coolant recovery tank for the overflow and it's not losing coolant or getting water in the oil. I'm worried about taking it any distance since most of the posts say it should be staying below 200*.
 
How many rows of tubes ?,what is the spacing of the tubes.Over heating at highway speeds is usually not enough radiator capacity.radiator repair shops will sometimes put in a core the same as the newer cars to keep costs down but there won't be enough area to remove the heat,
 
With your infrared thermo, check the temp at the top of the radiator and then at the middle and the lower tank, temp should lower as the radiator cools. Check the temp of the heads to try and identify hot spots.
 
I had a 48 merc that overheated with a3-row core.Had it recored with a 4-row core & all was well.The F H,s are heat generators with the exhaust going thru the block to the manifolds so they need a lot of core to keep cool.
 
It has two rows of two tubes staggered (4 row?), about 5/8" wide tubes. Its a new NAPA belt and it's tight, I can't turn the water pump pulleys against it.

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I think it has to be timing or a head gasket. Maybe I'll ship the distributor to Bubba's to look at. If I retarded the cam by putting it in a tooth off the timing would still be retarded even at full advance. The timing gear is pretty self explanatory though. Its been over two years since I assembled the engine and broke in the cam.
 
Run it at a fast ideal taking note of the temperature ,Then place a house hold fan in front and run it the same time and note how it lowers the temperature for the same period ,If it does I would suspect the Radiator has to few tubes for the no sleeve engine ,To test and advance the timing(temporally ) . Remove the advance plate and push it up using the screw hole with a sharp object ,Itl stay there long enough for a min test .
 
I'd take the starts out. At 55mpg you should be under 3000 rpm. unless you have 4:11 gears. I build alot of those type engine, remove the sleeves and bore another .045 to make a 239ci. I use the stock 59AB gaskets. Do you know if the block was cleaned out good? I've seen blocks that have cleaned with just a jet washer and the back of the water jackets around the rear cyl half fill with crud. I have all my blocks oven baked and short peened, the water jackets are clean. I always take a pen light and look down the big water holes in the back of the block. You can see right down to the pan rails. How is you compression? If the timing gears were off a tooth your compression should be a little low. Next move, take a good compression test with the throttle blocked open. With those heads you should have good comp, around 120# Walt
 
Walt the stats he has have a full flow opening almost the size of the hose. Plus he stated it ran hot even without the stats. 41 your distributor was set up by Skip on a Ford~Heyer distributor machine and was set to the Ford factory specs. I wouldn't fool with it and put the timing and vacume back were it was or send it back to Skip and he will reset it for shipping only. I did some work on a friends car a number of years ago that was sent to a lot of shops in the N.J., N.Y. area and got nothing but a pile of bills. He shipped the car down to FL. and in about 1 hour I suspected it was out of time. Skip loosened the crank pulley and removed the timing cover and I took a mirrow and flashlight and found it was 1 tooth off on the timing gears. I went away for 2 hours and Skip pulled the cam gear moved the crankshaft a little and when I returned he had it running and the problem was gone. I don't know if it over heated before we fixed it because it wasn't driven enough over the years it had the problem in hot weather. The owner had me drive it when I was up PA. before fixing it, It felt like the front end was shaking some. I put the clutch in going about 35 miles per hour and the shake stopped. I thought maybe the engine was out of balance but turned out as described above. Call Skip for help. G.M.
 
like Walt if your block was not cleaned out you could have dumped crude in to the Radiator ,but looking at your photo it looks clean enough .Its a small job to remove the front cover to check the marks .I had a customer who had the same problem and did a expensive rebuild work on his Radiator. He was looking at the stock (faulty )Red liquid Gauge sitting on the high side . He also went through several caps before he found one that had the correct reach .
 
The tubes look great from the radiator cap hole, but what about the sides. Had the same problem and replaced the radiator and had to install thermostat to bring the temp back up. Sometimes looks are deceiving
 
Back flush that radiator and use a screen to see what comes out. I couldn't believe what I got and mine looked clean through the holes just like your picture. Mine runs cool now.
 
I bought a specially built two core radiator for mine. Replaced a four core. Had the same problem as you, overheating on the highway. I now run a about 185* at 70 MPH which is about 3000 RPM on mine.
Butch
 
Thanks for all the suggestions. I got the timing cover off and the marks are aligned. I have an Isky 77-B cam and I noticed that the adapter button isn't quite seated in the cam gear. My distributor turns freely and looks fine. I wonder if the cam adapter is putting a thrust force on the back of the distributor? But that shouldn't affect timing.

I assembled the engine and broke in the cam in January a couple years ago. Other then that it didn't get driven until March this year. The temp seemed to run OK until the warmer weather recently. I didn't fiddle with the timing until a few weeks ago. I had driven to a local cruise night and the temp gauge was pegged when I shut it down. I attributed that to stop and go traffic. I was vapor locked when I went to start it again and even after swapping pumps and priming it I finally called a roll back truck. So I just got my electric fuel pump in last week and am taking it at highway speeds for test drives. I'm trying to rule out everything else before investing in a new radiator.

I'll box up my distributor and send it back to Skip for a recheck. I am still hoping to get up to the EFV8 club meet in Chugwater WY next week. I'll be the guy in the Ford Escape...
 
Oh, as for stuff in the block, my machinist assures me he cleans every flathead out well, he said the core sand can stay around the back cylinders for years and he flushes them thoroughly. I couldn't wash the block when I got it back since he had already installed the cam and valves.

I did notice some fresh cam thrust wear on the inside if the cover. If the cam gear was on cocked, I'd think it would be more even as the high spot went around:

2012-06-10_10-01-33_553.jpg

I have to make a new gasket anyway and am using a little thicker fiber. Gotta go before the wife gets home and finds car parts on the dining room table!
 
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