Temp. differential side to side

[elmangle]

I've read several threads recently stating that it's common for one side of the engine to run as much as 10 degrees hotter than the other, and generally the passenger side will be the hot one. Any reason why that would be and any idea why mine runs 10 degrees hotter on the driver's side and stays generally around 195-205 degrees in mild weather? No sniffable exhaust gasses in the cooling system, but the exhaust will always fog a mirror, no matter how long the engine has been running.

[tubman]

I checked mine out a couple of years ago with my remote infrared thermometer. My engine ran about 8 degrees cooler on the (American) passenger side. I chalked it up to the extra coolant on that side contained by the heater and hoses, even when it is not being used. That's just a guess, though.

[Mart]

Well, you do have a thermostat on each side (don't you?). I wonder if it would still be the same if you swapped the thermostats from one side to the other???

Mart.

[JSeery]

Your running hot issue could be any number of things, but if the block has never been cleaned of casting sand and wire that would be my guess. It could have something to do with the difference in temp side to side as well.

[FlatheadTed]

Its possible that the tubes on one side are partly blocked ,even though its a shared system the suction on the bottom tubes don't allow to water to mix ,Ted

[rotorwrench]

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All sorts of variables there. Stock cross over exhaust or duals with headers? Coolant flow was already mentioned. You have to keep in mind that there are basically two coolant systems that only share the same radiator. One side being used for heater was also mentioned and it does affect flow somewhat. Maybe some variance in cylinder compressions from side to side? Who knows?

[elmangle]

Thanks for all the advice, guys. I bought the truck from a friend who had the engine rebuilt about 20 years ago and then stored until he finished the restoration about 2 years ago. It was not yet broken in when I got it. I suppose it's possible that the builder did a poor job and didn't boil out the block, but it runs smoothly, has good power, and doesn't burn a drop of oil. There's no heater. A few months ago I pulled the left head and replaced the head gasket and checked as best I could for cracks, by using the acetone method, and had my mechanic check the head for warpage. All looked OK and I put it back together, torqued the heads a couple of times, all to no avail. Can the casting sand be removed without too much disassembly?

[G.M.]

Originally Posted by elmangle

I've read several threads recently stating that it's common for one side of the engine to run as much as 10 degrees hotter than the other, and generally the passenger side will be the hot one. Any reason why that would be and any idea why mine runs 10 degrees hotter on the driver's side and stays generally around 195-205 degrees in mild weather? No sniffable exhaust gasses in the cooling system, but the exhaust will always fog a mirror, no matter how long the engine has been running.

Put a bottle of Barr's heavy duty block sealer with the copper flakes in.
Block the over flow and run it up to 205 F. Shut down and let sit over
night before removing the cap. This will push the Barr's into leaks.
Remove plug from over flow, run and see how it looks. G.M.

[uncle max]

Sometimes has to do with cooling effect of oil splash.

[Lawrie]

Could be, I have just put on an oil temp gauge,cold oil is 25C normal driving in the heat up to 75 C, haven't done any pulls uphill yet,but will be intresting with the van on up a big hill.
Lawrie

[cas3]

sand and rust and all sorts of crud is usually laying all across the bottom of the water jackets. generally, you would go after this while preparing a bare block for a rebuild. just the hot tank at the motor shop will not get it all, it takes lots of scraping and chipping with a long skinny screwdriver, and or a long drill bit. chip and scratch until your wrist hurts, then tip the block and dump out a pile, then twist the drill bit down by hand and you will find your not at the bottom yet!!! its a nasty job and some will yield a coffee can full of crud. i have an old motor i want to run so i am going to try and do it with a vacuum cleaner as both heads are off.

[JSeery]

Was going to post what cas3 said! Tanking the block does little to nothing as far as removing core sand goes. I just cleaned a block that had been through several rebuilds over the years and a LOT of core sand was still in there!

[deuce_roadster]

I am with Max-the spinning crankshaft throws more hot oil on the LH side of the block.
I personally have never had an overheating problem with any of my flatheads. In fact, my avatar roadster would not get above 110 degrees with no thermostats and ran like crap. Block was Redi-stripped and it has a highly efficient radiator that Griffin said would cool a blown BBC.

[tubman]

To add to what I said; although my engine runs 8 degrees difference between the banks, I have never had an overheating problem since I had the radiator re-cored over 30 years ago shortly after I got it.

The reason "uncle max" and "Deuce Roadster" give makes more sense than what I was surmising.

[elmangle]

G.M. Worth trying. I used the Barr's about a month ago but didn't block the overflow as you suggest.

[Talkwrench]

Yes they can contain some crud... That was just a small amount I scraped out.. But some temp variances are normal because of the two halves.

[G.M.]

Originally Posted by JSeery

Was going to post what cas3 said! Tanking the block does little to nothing as far as removing core sand goes. I just cleaned a block that had been through several rebuilds over the years and a LOT of core sand was still in there!

There's more hoopalaw over sand in the block than effect it
has on over heating. Number one if there is sand it was there
since new and all old Fords had a small amount. Where it lays
down on the pan rail, that area of the block doesn't do much
cooling. Oil heats up fast under heavier loads. I has a 78 GMC
motor home I put a 500 caddy engine in with digital gauges.
It had an oil temp gauge and on hills the oil temperature was
the first thing to raise followed by coolant. I would watch the
gauges and it was predictable how they would work. G.M.

[JSeery]

Originally Posted by G.M.

Number one if there is sand it was there
since new and all old Fords had a small amount. G.M.

That would be true, but the amount I have removed is not what I would consider a small amount and it has been mainly around the rear cylinders and not along the pan rails.

[rotorwrench]

The core wire they used to hold the cores in the mold also held a lot of the core sand. I sent a 51 Merc engine block, from a car that had been in the family since 1954, out to a Ready Strip place and he filtered a large coffee can full of sand and wire out during the block cleaning. We had never experienced any overheating due to this. There were water pump & radiator problems over the years but after they were repaired the car went right back to normal temps.

[JWL]

I have explained the technical reason for one half of the engine to show higher temps than the other. One more time---- The ports are different lengths from left to right bank. With the longer intake port and shorter exhaust port holding a slight advantage over the short intake port with longer exhaust runner of the opposite bank.

[G.M.]

Originally Posted by JSeery

That would be true, but the amount I have removed is not what I would consider a small amount and it has been mainly around the rear cylinders and not along the pan rails.

I would think almost all the sand would be down on the pan rail
with all the water movement around the cylinders for many years.
A lot of the heat is generated around the exhaust ports as JWL
said. Cast iron deflectors held in by head stud help this problem.
G.M.

[elmangle]

Is there any way to check the functioning of the water pumps while the engine is running? I have tried about everything else but this truck wants to run hot. Yesterday I drove it up the mountain about 1500 ft. in 50 degree weather and checked the temperature at the top. 213 on the driver's side and 200 on the passenger side.

[G.M.]

Originally Posted by elmangle

Is there any way to check the functioning of the water pumps while the engine is running? I have tried about everything else but this truck wants to run hot. Yesterday I drove it up the mountain about 1500 ft. in 50 degree weather and checked the temperature at the top. 213 on the driver's side and 200 on the passenger side.

Are you filling the coolant up into the filler neck??
Is it still filled after it gets to 200?? You may not
have the full 22 quarts required to cool these engines.
G.M.

[FlatheadTed]

The suggested possible causes in the different temp from side to side all good advice.As far as hill climbing I would think your Radiater is blocked or its under sizeded for your moter ,read Deus Roadsters post again .efficient radiator that Griffin said would cool a blown BBC.Model As and Ts had no cooling at the lower part of the cylinders and they worked ok ,that's not to say the crud cannot affect things .If a new radiator has been fitted what's not addressed often is the chance of crud coming out of the block and in your case it sat for twenty years so likely lots of rust building up and the heat and cold cycle braking it loose .We now put stockings in the top hoses (picture here ) this catches a lot .We just sent out a 34 three window with a re cored radiator ,we left the stockings in and the owner has changed them once and is finding all sorts of rust etc coming through from the block ,you could try a shroud or high flow pumps both will improve what could be a Radiator problem ,We work on flatheads all day every day .Ted

[elmangle]

Flathead Ted: Thanks. I suppose you might be right about the radiator, but a close friend of mine did the restoration and it's unlikely....but possible.....that he would have used one that was not good....then again. I checked it with an infrared thermometer and found no cool sections, but who knows. Using your stocking trick surely can't hurt. What continues to puzzle me is that I still can fog a mirror with the exhaust, but there is no sign of exhaust gasses in the cooling system. I'd like this baby to be as reliable as my '40 Century, that I drove today for 232 miles, with altitude changes from 5200 to 9200 feet, and the gauge never moved off of 180, except for cooling down a bit on the long downhills. I'd like to be able to tour like that in the Ford, too. No garage queens at this house!

[flatford8]

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Combustion causes moisture.....is the fogging of the mirror just that?.... Mark

[FlatheadTed]

Good to here they are all daily drivers .Usually a cylinder leak dumps water out the over flow .You could try a block sealer ,I have had good results from it ,not sure of your brands ,purple Ice ?purple haze ?any thing you put in can reduce the efficacy of the radiator of course ,the one picture d has had the vinegar washing soda trick,Ted

[elmangle]

Don't know, but my other cars don't do it.

[FlatheadTed]

I have heard of a crack in a exhaust port ,

[Kahuna]

If you have 2 gauges, it could be the gauges themselves.
I run 2 electric gauges on my flathead & there is a difference
in the temperature readings. About 4 degrees. Verified by
switching connections. Just a thought.

Jim

[elmangle]

Thanks, but I've checked it with an infrared thermometer.

[elmangle]

Wouldn't that inject exhaust gasses into the cooling system instead of pulling coolant into the exhaust system? Would a crack into the intake side pull coolant into the combustion chamber and then exhaust it along with the combustion byproducts? Obviously I'm not too smart about this stuff.

[40cpe]

There seems to be 2 symptoms: Fog in one exhaust, and running warmer than desired. Both could be caused by a combustion leak. There is a test for that. Is the truck loosing an appreciable amount of water?

[elmangle]

It's a stock-type single exhaust system. It loses a little water over time, but I think that's mainly because my expansion tank isn't quite big enough. I did take it to a shop and have the system "sniffed" for combustion gasses and nothing showed up. I live in a rural area that doesn't require smog testing, so don't have a shop within 65 miles that could actually check the exhaust moisture content level to ascertain whether it's normal or not. Looks like a road trip to the city and a visit to the radiator shop and smog station.

[elmangle]

Overheating Solution!!!! (at least partial). I was going through some of the records that came with the truck when I bought it, and noticed something interesting. The truck came with an electric fan only, and the temperature sensor was one that activates the fan at 200 degrees, and the sensor was installed on the right bank, which always runs about 10-12 degrees cooler than the left bank, which means that the fan did not come on until the left side reached over 210 degrees. I wired the fan direct and took the same test drive and guess what.....the gauge showed 200 at the steepest part of the climb and lowered to 185 by the end at my house. Of course it was a cool day, but I have to think a 25 degree difference is significant. Apparently a cruising speed of 45 mph does not provide enough airflow without the assistance of the fan. Thank you all for all the advice.

[elmangle]

Ordered a temperature sensor that will start the fan at 180 and turn it off at 165, meaning 190 and 175 on the hot side. Will let you know how it works. Think I'll install a manual override to boot.

[elmangle]

Just a quick update and related question: Pulled the head again to check again for cracks with a penetrant dye kit, and both the block and the head looked fine. Before pulling the head I ran the engine with the upper hose and thermostat housing removed and started to get some bubbles at around 170 degrees and quite a few around 195. So apparently there's combustion gasses getting into the coolant somewhere I can't see it. Big mystery. No bubbling on the passenger side, which is the cool side. A related question: I noticed that the composite head gasket has only a small hole where it matches the bottom "teardrop" passage, but the copper gaskets meet that hole shape completely. Any reason for the difference, and would it in any way affect cooling?

[19Fordy]

JWL's reply seems the most plausible.

[elmangle]

Thanks....I agree. I'm not that worried about the differential, but I am puzzled by the source of the exhaust/compression gasses and the difference between the 2 types of gaskets.