Cold weather driving with or without thermostat?

[The Master Cylinder]

Nice looking setup Al. After the engine heats up I wonder how much HOT water is bypassing the radiator to the rear cylinder with cooled water entering the middle of the block. Just thinking out loud.

 

[ryanheacox]

Didn't add the photo attachment.

I really like the look of that

 

[AL in NY]

My thinking is only about 5% of the hot water exiting the top of the engine goes through that 3/8" bypass tube when the thermostat is open. The 1 1/2" top radiator hose drops the pressure at the thermostat to nearly zero.

 

[Jim/GA]

https://vintageprecision.com/products/thermostat_housing/index.html

Jim, purchased one of these. Could you run a hose out of one of the lower plugs?
Have been using cardboard but not the best in cold rain,snow.

Yes, taking hot coolant out of one of those ports will work.

I switched to thin masonite instead of cardboard after my first rain storm. Cardboard kind of falls apart.

Back in the Model A era they sold a radiator cover made of vinyl with several snaps that could be used to hold two flaps open with different opening sizes. So you could get out and adjust as required while out driving. I have only seen pictures, never seen one in real life. I might try to make one. I think my wife could sew it up if I design the pattern. Maybe use velcro instead snaps.

 

[160B]

FWIW

Here is a winter photo of our 1931 68b with a card board winter front on a New Year’s Day tour, 1/1/2017. I use water with a water pump lubricant and rust inhibitor, 160 degree thermostat, warm engine up in drive way before traveling. Have done this for years with no problems. One year it was 16 degrees for the New Year’s Day tour. Car is stored in a heated garage.

 

[Dick Steinkamp]

Just my experience on this subject...

I put a T-stat in my Model A recently. Only because the water pump continued to push water out the overflow tube...nail or no nail. Tom had suggested the T-stat to correct this and it did. Thanks, Tom!

I was all over the engine with my laser thermometer for the first start ups and drives to see how and where it was warming up and to insure there were no hot spots. I noted nothing unusual. Quite even warming on all parts of the block and head, and faster warm up than without the T-stat. The holes in the T-stat housing do let a noticeable amount of warm water through.

My other two collector cars are an MGB with a 3.5 Rover aluminum V8 and a 914 Porsche with a small block Chevy V8. Both have T-stats and no bypass tubes. No cabin heaters. Both cars warm up smoothly on the temp gauges. No cooling problems on either. The Porsche is a mid engine car with the rad in the front. I can feel the top hose at the rad getting warm long before the T-stat opens. The small holes in the T-stat housing pass a lot of water.

I've owned several 50's and 60's cars with T-stats and without bypass tubes. The only ones that would come close to having a bypass tube would be those with cabin heaters and then only when the heater was on. All worked fine.

I'm thinking that if blocking the rad and not having a T-stat was a preferred method, we'd be using the same method today. I also can't think of a newish car that has a bypass tube (unless you count those with heaters with the heater always on).

Again, this is only my experience. But based on it, I would not over think or over engineer this issue. If there is any data other than just our anecdotal evidence or opinions, I could easily change my mind.

 

[Davew]

Like the vinyl cover idea. Probably look ok also

 

[Jim/GA]

<snip>

I've owned several 50's and 60's cars with T-stats and without bypass tubes. The only ones that would come close to having a bypass tube would be those with cabin heaters and then only when the heater was on. All worked fine.

Actually, I would bet that some form of bypass was there, if there was a thermostat in the water outlet; you might not have been aware of it, but it was there. Yes, the heater core counts as bypass if there is no valve on the hot water line. My 1980 F-150 was like that.

I'm thinking that if blocking the rad and not having a T-stat was a preferred method, we'd be using the same method today. I also can't think of a newish car that has a bypass tube (unless you count those with heaters with the heater always on).

Having a thermostat is preferred, for faster warm up (less air pollution). The modern style thermostat with the wax pellets in it was not invented until 1934, so did not show up in cars until then and after. My '41 Chrysler had one of these thermostats, and it had a very short bypass hose between the top of the water pump and the thermostat housing.

My '50 Buick had something similar (hose was about 1 inch long).

By the time GM got to my '63 Buick, they had a cast piece of metal and an o-ring on the thermostat housing that pressed down into the water pump housing to bypass coolant when the thermostat is closed. There is no hose. That is common today on all modern engines -- bypass is built in, no hose. But the bypass is still there.

Again, this is only my experience. But based on it, I would not over think or over engineer this issue. If there is any data other than just our anecdotal evidence or opinions, I could easily change my mind.

Before the thermostat was available that went in the coolant outlet, high-end cars (not Ford) had movable louver shutters that mounted in front of the radiator. A bi-metallic element on the radiator upper tank pulled the louvers open when the engine warmed and then closed them again when it cooled. So it was automatic (and looked cool).

On my S/W Town Sedan, with a 160* thermostat and the valve in my bypass line closed (so no bypass) I can watch the coolant outlet temperature swing fairly wildly between hot and cold from cold start up and initial drive, until it settles down. That's real data in my book.

The thermostat in this car is not close to the water pump, it's up closer to the radiator neck. I suppose moving the thermostat closer to the water pump would lessen the swings. For other reasons, that would not be easy for me to do on this car.

I would not over think it either. Just block the bottom 1/3rd of the radiator and go drive your car! Have fun!

 

[30 Closed Cab PU]

Think I've seen the method used in the previous picture before. But I believe you have to drill/tap a hole in the back of the motor block (cylinder 4) for the bypass line?


Still looking forward to a picture of Jim's setup, when he has time. From his description drilling/tapping is not needed.

 

[Tom Wesenberg]

I use a 180 thermostat all the time, and it has a couple 1/8" holes to allow the hot antifreeze to pass by the wax pellet. I also have a 5/8" bypass hose for engine coolant circulation. This hose will later pass through my heater core for cabin heat. This works great.

 

[30 Closed Cab PU]

I use a 180 thermostat all the time, and it has a couple 1/8" holes to allow the hot antifreeze to pass by the wax pellet. I also have a 5/8" bypass hose for engine coolant circulation. This hose will later pass through my heater core for cabin heat. This works great.

Did you fabricate the bypass hose fittings into the upper neck and lower block necks? Or are they commercially available?

 

[Ernie Vitucci]

Good Morning all...I run a cloth napkin held on the light bar by two safety pins. It covers about 1/4 of the radiator. Seems to work great. Any upholstery shop could make one out of leather and put two snaps on it to hold it to the light bar. Simple is better in my humble opinion. A motor meter with a thermometer in it helps a lot...Have a great Model 'A' Day. Ernie in Arizona

 

[ryanheacox]

I've seen those vinyl (or maybe leather) covers on Model T snowmobiles on youtube. I like the look of them too.

I used a piece of cardboard that covered a little less than half the radiator today and it seemed to work great. The motometer never showed any red (it doesn't in the summer either, only when pulling a long hill). If I end up doing a fair amount of cold weather driving I think I'll have a radiator cover made up.

On another note, the new engine seems to love the cold. Went to start it to go home after sitting for 5 hours at 14 degrees and it didn't even crank once before it started.

 

[Tom Wesenberg]

Did you fabricate the bypass hose fittings into the upper neck and lower block necks? Or are they commercially available?

I found the inlet casting at a swap meet, and drilled and tapped the outlet.
I went to a plumbing store to borrow their pipe tap.

 

[eagle]

I don't have to worry about cold weather driving here in Minnesota, there is so much salt on the roads by the time it is cold here that only a fool would run any car they loved on them. Can't fix salt rot.

 

[Tom Wesenberg]

I don't have to worry about cold weather driving here in Minnesota, there is so much salt on the roads by the time it is cold here that only a fool would run any car they loved on them. Can't fix salt rot.

For sure!
The roads and ground water are polluted with road salt before the first snow even falls. It sure cuts into driving time for our antique cars, let alone the safety issue of rusted fuel and brake lines on modern cars.

 

[ArtimusGordon]

That is what I do in the fall, when the temperature drops, then in the spring, when the weather starts to be warmer, I remove the cardboard. Easier than messing with a thermostat. (PS: I do paint the cardboard BLACK!)

 

[30 Closed Cab PU]

Think I've seen the method used in the previous picture before. But I believe you have to drill/tap a hole in the back of the motor block (cylinder 4) for the bypass line?


Still looking forward to a picture of Jim's setup, when he has time. From his description drilling/tapping is not needed.

Did another search and want to verify. I found a post that seems to indicate that the hole is present and tapped in the back of the block for a heater hose connection?

 

[Jim/GA]

Did another search and want to verify. I found a post that seems to indicate that the hole is present and tapped in the back of the block for a heater hose connection?

That is ONE option to run the water back to the engine from the heater core.

The OTHER option is to tap into the water inlet on the side of he engine. You can find these inlets with the hole drilled and tapped at flea markets up north. They were very popular. I prefer this option because it is so easily reversible.

The Model A parts guys sell these inlet castings with a heater/temp gauge port new, but they ask crazy money for them. Look at a Swap Meet.

 

[Richard in Anaheim CA]

I always thought those tiny holes in the thermostat could pose a problem, so years ago I took my trusty Harbor Freight tapered step drill to the holes and have two .250" holes in my thermostats.

I measured the inside of the "barb" for a 5/8 heater hose and it measured .430.

The area of a circle is 3.14 X radius squared.
I ran into a problem squaring numbers less than 1 so am not sure how my [2].250 holes compare with a single .430 orifice. I guess I should have paid more attention to Mr. Redford in math class.

I do know that my cars do fine in all types of weather with my modified 160* thermostats.