Thermostats, To Use or Not to Use

[Slopey1939]

Greetings,
I am hoping to get some input regarding thermostat use. Initially when I purchased my 39 (orignal flathead) it had the usual inherent overheating issues. I struggled with it until I took advantage of Skip's high capacity water pumps which corrected the problem. In do so I left out the two thermostats. On a cold day (low 50's I know that isn't cold but this is California) it will run 120 to 140 on the freeway. Stop and go a little more. On a warm day, low 80's it will run 160 or 180 if there is some stop and go. Some has said this is too low of an operating temperature. Any one have a problem with this and if so what thermostats would you/are you running? 160 or 180? Thanks for any advice.
Dave

[VeryTangled]

Use 'em.

[Slopey1939]

Thank you!

[deuce_roadster]

My flathead in my avatar roadster doesn't run well until it is above 150. I don't even try to drive it until it gets there. Running 180 stats and it RARELY goes above that to 190. It is my opinion it is not good on the engine to run it relatively cold all the time.

[51 MERC-CT]

Originally Posted by Slopey1939

Greetings,
I am hoping to get some input regarding thermostat use. Initially when I purchased my 39 (orignal flathead) it had the usual inherent overheating issues. I struggled with it until I took advantage of Skip's high capacity water pumps which corrected the problem. In do so I left out the two thermostats. On a cold day (low 50's I know that isn't cold but this is California) it will run 120 to 140 on the freeway. Stop and go a little more. On a warm day, low 80's it will run 160 or 180 if there is some stop and go. Some has said this is too low of an operating temperature. Any one have a problem with this and if so what thermostats would you/are you running? 160 or 180? Thanks for any advice.
Dave

In order for skips pumps to operate as advertised, I believe he requires that thermostats NOT be used.
What I would consider is to partially block the radiator air flow when the ambient temperatures are low to bring the engine to a suitable operating temperature. Then remove when ambient temps are high.
Otherwise I suspect you wasted the money on something that solved an overheating problem.

[alanwoodieman]

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I use a cardboard thermostat and skip's pumps all three of my flatheads and the heat here can be in the 90's or above with high humidity. they all run in the 160/180 temp range in the hot temperature

[51 MERC-CT]

Originally Posted by alanwoodieman

I use a cardboard thermostat and skip's pumps all three of my flatheads and the heat here can be in the 90's or above with high humidity. they all run in the 160/180 temp range in the hot temperature

Have to agree with the cardboard thermostat in front of the radiator.
As a matter of fact, many modern cars use shutters in front of the radiator to keep engine at operating temperature.

[Ford Freak]

I have 180's in mine. Always runs 180-190, no matter how cold/warm it is outside.

[JSeery]

Your running the engine way to cold, it needs to be at least 180 and 190 is better. Flathead do not overheat unless there is an issue. Buildup in the block, partially clogged radiator, low air flow, etc. The best approach is to fix the problems.

[big job]

I agree with 51Merc.. This is a topic like the good and the bad. My brain was pounded to see the temp. gauge in the middle '179- 180' and then Model T's like around almost boiling thats its nature. 1930's Chrysler products with those honey comb radiators was a must for a thermostat to give the radiator time to recuperate heat. Then from school in family bus co. coaches with Detroit diesels, high temp. thermostat is a must plus they had air shutters to block the radiator. complaints were very little heat from heaters because kind of like the Detroit was half water and air

cooled (the blower).. I remember the coldest days like -0- we left buses run all night
like with a train engine the EMD diesel a big time version of a common 6-71 Detroit. I ask a rail road worker about why they run just idling. Oh we shut them down once a year for oil change etc. If we do not, it will be a project in the winter to start them up. Then I had a Corvette where as 210' on the gauge was normal. So in closing I shall stick with a cardboard which I will remove in June when the ice melts. So use them or not as long as it is not puking steam and coolant.

[tubman]

Originally Posted by 51 MERC-CT

In order for skips pumps to operate as advertised, I believe he requires that thermostats NOT be used.
What I would consider is to partially block the radiator air flow when the ambient temperatures are low to bring the engine to a suitable operating temperature. Then remove when ambient temps are high.
Otherwise I suspect you wasted the money on something that solved an overheating problem.

Is this the straight scoop? It doesn't seem right to me.

[51 MERC-CT]

Originally Posted by tubman

Is this the straight scoop? It doesn't seem right to me.

See this thread from 8 years ago, post #64---


https://www.fordbarn.com/forum/showt...=106054&page=4

[JSeery]

Tubman, that is the claim, but I find it a bit absurd. An engine needs thermostats to operate properly and thermostats are not going to cause overheating. If there is an overheated issue, the source needs to be determined and corrected. IF installing higher flow pumps improves an overheating condition with no other changes, I would consider that a band aid type of fix masking a problem.

[mfirth]

Thought i saw a Skip add that featured stats for those engines....??? I'd want stats if it were mine.

[aussie merc]

engines are designed to run stats henry wouldn't have run then if he didnt need to your in southern cal very similar to nsw so i would be looking at 170s but deffinately in a high flow type

[Shu47]

Put the thermostats in. They allow the engine to operate at the correct temperature.

[koates]

Some thermostats are by design a bit restrictive even when fully open. That is usually the poppet valve type that just moves up and down. I prefer the butterfly valve design which is less restrictive to flow when fully open. You need all the coolant flow possible on a hot day with no restriction at all. I have the butterfly type in my 34 Ford which seems to work well. They are both older manufactured 170 deg. F. types. I always test both in a jug of boiling water to make sure they are both opening together. Regards, Kevin.

[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.

[48fordnut]

Ralph, don't fix something that isn't broken.

[Slopey1939]

Thank you all gentlemen. Many different theories. Looks like I will go with the "custom" thermostats that Skip recommends to go with his water pumps.
Thank you all for your input!!!
Dave