Thermostats, To Use or Not to Use

[Tinker]

Depends on the climate you live in. To me anyways. Temps are to raise the block temp quick. Doesn't seem a good idea if you live in Arizona. If you run in a cold climate for sure.


Warming the block helped warm the intake helping with atomizing fuel. I'd guess none of us gets up in the morning and fires up a Flathead in south Dakota in nov let alone feb.


But if you are in canada like Ralph, you might have to start a small fire under the block in feb to get it going. Probably the last thing I'd worry about is a stat.


Restricting waterflow is a concept. Not sure it makes it cooler as temps restrict by design. Clean your block and have a clean rad and you will be better off.

[Slopey1939]

Thank you Tinker,
Northern California. Hot days (90+) are not that often. And it runs fine now with that temperature. There were some comments about other issues causing the over heating. There was nothing that I could identify. It had minor ignition problems but the cause seemed to be unknown. I flushed the radiator (vendor told me it was fine), rebuilt the distributor, replaced the plugs and wires and still running hot on hot days with stop and go or freeway driving. I remember my dad had a 47 2 dr coupe. In the early 50's it overheated, overheated and overheated when confronted with grades. All good now with the Skips water pumps.

[RalphG]

For sure the old flathead runs better when its warmed good but a piece of cardboard in front of the radiator can help with that.
Back in the sixties when the Merc was the family sedan my dad had problems starting it in extreme cold sometimes, even with the block heater. I've started it at well below freezing temps without major problems. If necessary I'll put 12 volts to the starter which makes a world of difference to cranking speed. I had it out for a spin on February 2 this winter. Started on 6 volts.
https://youtu.be/NF6OlnCP_1I

[Tinker]

It's just my thoughts. We all have different experiences.


Ralph I didn't mention you in a negative, but more as a friend. Get it hot quick!

[Tinker]

Timing and lean carb can have an effect on heat. Never bad to take a coat hanger/long screw driver to the back of the block and a flush with house water (pressure) to a regular unknown block with the heads off while in the car. Ya you will have to buy new head gaskets.


If you manually clean the sitting block don't keep the rad connected. Seems like a simple thought. But hey.

[tubman]

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Originally Posted by RalphG

You guys have almost talked me into trying thermostats in my 52 Merc. I don't think my dad ever had them in the car and I've never used them in the 6 years I've been running it. As I recall the head temp is usually in the 170+ range when I check it with the infra red heat gun so I figure thats not bad.

I have to believe that the 8BA series of engines are in a whole different class than the earlier engines when it comes to cooling problems. Most of the changes made to them involve improvements to the cooling system. The stock water pumps already have the improved impellors, so "Skip's Pumps" are not the improvement they are on the earlier cars. The thermostats are of a more modern design and are mounted in a reasonable manner. The reason the water outlets were moved to the front of the heads again was to improve the waterflow and therefore cooling.

I believe that it is doing a dis-service to these engines to not use thermostats in a later flathead, unless, of course, you have serious problems with a restricted radiator or block. All bets are off then and you have to do what you can.

[51 MERC-CT]

Originally Posted by tubman

I have to believe that the 8BA series of engines are in a whole different class than the earlier engines when it comes to cooling problems. Most of the changes made to them involve improvements to the cooling system. The stock water pumps already have the improved impellors, so "Skip's Pumps" are not the improvement they are on the earlier cars. The thermostats are of a more modern design and are mounted in a reasonable manner. The reason the water outlets were moved to the front of the heads again was to improve the waterflow and therefore cooling.

I believe that it is doing a dis-service to these engines to not use thermostats in a later flathead, unless, of course, you have serious problems with a restricted radiator or block. All bets are off then and you have to do what you can.

Yes, the 8BA series allows the choice of high flow thermostats such as Robershaw which reduce resistance to flow and any need for increased flow water pumps.

[JayChicago]

Here is a thought. I don’t know about this, just throwing it out here. Wonder what others think:

Is restriction of the water flow at the thermostat really a thing? Seems like it might be because it’s easy for us to picture that. But all water at the stat had to get there thru the tiny passages in the head. And that might be the most restrictive point in the system.

As long as the stat opening is large enough to handle what is delivered to it, larger stat isn’t going to improve circulation.

[51 MERC-CT]

Originally Posted by JayChicago

Here is a thought. I don’t know about this, just throwing it out here. Wonder what others think:

Is restriction of the water flow at the thermostat really a thing? Seems like it might be because it’s easy for us to picture that. But all water at the stat had to get there thru the tiny passages in the head. And that might be the most restrictive point in the system.

As long as the stat opening is large enough to handle what is delivered to it, larger stat isn’t going to improve circulation.

If you think about it, the many small passages exceed the area of the one thermostat location which makes it a point of restriction.

[flatjack9]

Any thing that makes the flow area smaller is by nature a restriction. The question is, is it enough to negatively affect cooling. I have thermostats in my engine and I can say without a doubt it has not hindered cooling in my engine for 25 years of operation.