Flathead running cold

Thermostats are always a good idea. Every car that has come off the production line in the last 75 years has them. Stats given you faster warm up of every thing including oil. Cold running is a killer on engines greatly increasing wear and hence decreasing engine life. Also the warmer the engine the greater the engine efficency /performance hence you want to run as hot as you can short of boiling. Ford started using stats in 1934. I think then he used 150F or 160F stats. We now know that the thinking was right but that's a bit low and that warmer is better.
 
Ok, ran the car up to speed at various speeds for over an hour with temps here mid 60's and the temp guage never went above 160. Forgot to mention that when I refreshed the coolant I used something called "Water Wetter"which is supoposed to lower radiator temps not thinking it would be a problem. Temps did get in the 180 range prior to that. In any event I'm probably going to 180 degree stats.
 
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If your radiator is up to the task why not go with the original 195 stats ?
We run theese engines for short periods and need all the heat we can get to keep condensation out of the engines.
Not to mention the engine performs better at higher working temp.
 
I'm back at the model A flathead after a short hiatus. Have the thermostats ready for install but decided now that it's warmed up a bit here I'd do an extensive around town drive. Well the temp guage hit a steady 175 degrees and the car seemed to respond favorably to stretching it's legs. However when I shut it down the overflow line from the underside of the radiator cap blew coolant all over the garage floor. Ok now what gives? Can't be running too hot! This is a new rebuilt engine,water pumps and radiator. I can't imagine installing 180 degree stats would help.
 
How full was the radiator? It doesn’t need to be up to the filler neck. When you shut the motor down, especially inside a building, residual heat can cause the expansion you experienced. Don’t refill all the way and try what you just did a few times to see if it stops puking.
There is a very experienced poster on here who has forgotten more than I’ll ever live long enough to learn about these vehicles, insists the rad must be full to the top,but since I was old to enough to reach the radiator, I was taught to not fill all the way up. Leave room for expansion......Mark
P.S.....can we see some more pictures of your car....thanks!
 
Running stats helps get the engine up to temp quicker. having the engine at a stable (higher) temperature is better for it. Have you tried not topping up the radiator? This will allow it to find it's own level and it will stop pushing excess coolant out.

Mart.
 
In follow-up to securing stats in place. There was a post on here, or on the Early Ford V8 site, where someone described inserting a short (1 1/2" +/-) piece of rad hose that fits tight into the engine end of each of the top hoses, where they connect to the engine. The piece is inserted the same depth equal to the distance that the hose will go over the spigot on the head.
I did this on my '46 59AB, when I put 160 stats in, after finding the PO had used mismatched stats, and one had turned sideways. After finding it ran too cold with the 160s, I pulled the hoses to install 180 stats, and now the engine runs nicely at +/- 180 deg. When I did the change, I found that all was good, as the stats had not moved. NAPA sells the Gates hose by the foot, under part number NBH 609 in the US, and UNR 609 in Canada. This hose fits quite tight inside the rad hose, so it stays in place.
 
Bring it down to where I live in SW Florida where it is 95 today
and we will see how cold it runs. G.M.
 
We have warm weather up here in Canada, although only for one week a year.:D It was 35 degrees Celsius +/- 95 F the other day, and the car ran along quite happy at 185 F. The only thing is the AC scoop on the cowl couldn't keep it comfortable inside the car.
 
51woodie said:
In follow-up to securing stats in place. There was a post on here, or on the Early Ford V8 site, where someone described inserting a short (1 1/2" +/-) piece of rad hose that fits tight into the engine end of each of the top hoses, where they connect to the engine. The piece is inserted the same depth equal to the distance that the hose will go over the spigot on the head.
I did this on my '46 59AB, when I put 160 stats in, after finding the PO had used mismatched stats, and one had turned sideways. After finding it ran too cold with the 160s, I pulled the hoses to install 180 stats, and now the engine runs nicely at +/- 180 deg. When I did the change, I found that all was good, as the stats had not moved. NAPA sells the Gates hose by the foot, under part number NBH 609 in the US, and UNR 609 in Canada. This hose fits quite tight inside the rad hose, so it stays in place.
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And what stats do you use. Part number for a 59AB with Offy heads
 
Revisiting my original entry into the ongoing thermostat saga. Bought Stant 14157 170 degree stats and they were too big for the Edelbrock water outlets. Fine bought Stant 1308 180 degree stats as suggested by a more seasoned flathead guy than I. They were also too big so I trimmed the O.D. to fit in the Edelbrock outlets. They had a snug fit so I thought great, they have less chance of flipping over. Tested the stats again for proper function using a infra red temp guage, Great opening fine! Installed the stats filled the cooling system....what a mess that was. Fired her up and watched the temp guage climb..up to 180..now we are cooking! Oops kept climbing,185,190, crap hit 245 and shut it down! Took continual remote engine temp readings at the water outlets and temp never reached 180 so the stats never opened. Engine block and heads were hot so temp guage is accurate. What a pain in the arse!
Drained the cooling system yet again. If I wasn't so utterly pissed and frustrated I'd think this almost funny.
Now I'm back to running no stats. Engine hits that magical 160 degree mark and stays there. Fight this battle again in the spring.
BY the way, Merry Christmas and happy and healthy New Year
 
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My thoughts; others may have a better explanation:

So your thermostats never reached 180 degrees, while the engine got up to 245. What could cause that? Trapped air sitting at the top of the heads against the thermostats so the stats are not sensing the true water temp?

I have read that it is a good idea to drill small hole(s) in the thermostat's flange to let trapped air below the stat pass through the stat. Small holes will let just a minimum amount of water pass, so stats will still function to hold back water until up to temp.
 
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Some thermostats have that provision (an air bleed hole) with a little jiggle pin that closes the hole when not needed. First thing I would recommend is to always check any thermostat before you install it (them). Put it in a pan of water and check the opening temperature. It is not that uncommon to find thermostats that are off or totally not functioning.
 
Thermostats were checked and appeared to function as designed. Thought about trapped air so next go round I'll drill holes . Just lost patience having drained and refilled the system too many times to my liking. The radiator is a an after market alum. unit that has no rear petcock so I am forced to remove the grille shell and drain it through a front drain plug. Grille shell won't allow for a petcock without butchering the grille. Coolant shoots out like a fire hose so capturing the coolant is a challenge. I now have the cleanest garage floor in the state!
 
Pictures of the installation. Ground clearance grooves for T- stat to sit in the well and had to trim O.D. of same to fit within confines of hose . Seems odd when looking at the temp gauge sending unit location that it would read 245 degrees and yet the thermostat sitting next to it wouldn't open? Wondering if air in the system did in fact create this problem?
 
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I feel your frustration about draining the radiator. The aluminum radiator in my '37 has just one fitting for a pet ****, and that fitting is now used for the electric fan's temp sensor. So I have to loosen the sensor and try to modulate the flow by hand, or loosen a lower hose. Either way, can't catch all the coolant in a container. Makes a mess, on the floor and down my arm. Ugh!

Maybe the gauge sending unit is picking up heat directly from its fitting, even though it's probe is in an air pocket?
 
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Captain obvious here. You do have the stat right side up (or in)? Also it is possible that a new stat can be defective. I'd try another.
 
run thermostats simple answer factory fitted them and trust me if they arnt needed then they would have left them out and saved the coin [henry was the worlds greatest tightwad] engines need to be held at a constant temp worst thing that can happen to them is temp fluctuations [greatest known cause of cracking]
 
there should be hole in the block behind the water pumps for drain petcocks to drain the system
 
cas3 said:
there should be hole in the block behind the water pumps for drain petcocks to drain the system
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Thanks for that info. I didn't know that. Will look for it. Is that true for a 59 ('46-'48) block? Would the the hole be tapped and plugged?
 
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