Flathead runs too cold

[rharv1]

Its 30 degrees outside and after a ten mile ride temp gauge reads about 125 degrees. Thermometer in radiator same temp. I have 180 degree thermostats that are new (my second set) and they aren't opening because both upper hoses are warm at best and with the motor running I see no turbulence in the radiator. It is a rebuilt 40 motor in a 35 pickup. Am new to flatheads and can't figure out my problem. I have no heat. Advise appreciated.

[Paul Bennett]

My dad always used a radiator cover on his '37 Ford on freezing Chicago winter days. Note that you can even get radiator covers for new trucks, some being automatic.
Cut a piece of cardboard to place in front of the radiator

[JSeery]

Yep, need to cover the radiator. It's a trial and error process to determine the % of the core to block.

[Ronnie]

Mechanical or elect gauges? Don't think stats are at fault a stat not opening would soon give you an overheat.Warm hoses usually relate to stats stuck open.What stats are u running?A rad cover could be in order.

R

[rharv1]

Mechanical gauges and meat thermometer in radiator all agree at about 120 degrees. Two different sets of 180 thermostats. Same results. No turbulence in the radiator with motor running and am convinced that thermostats are closed. You can hold your hand on the heads no problem. The only non stock thing is that I have 2" pipe dual exhaust all the way from the stock manifolds and they were hogged out to 2" also to match pipes. Don't know if the lack of back pressure allows heat to escape too quickly

[Ronnie]

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How are you keeping the stats in the hoses?

R

[flatjack9]

Are the thermostats staying put in the hoses? If they cock, water will bypass the stat.

[Old Henry]

Originally Posted by flatjack9

Are the thermostats staying put in the hoses? If they cock, water will bypass the stat.

Agreed. Common problem with the stats sitting on the head neck outlet. The stats turns 90° from pressure underneath and do nothing, even if they're fully closed.

I hold mine down with a short piece of one strand of stranded wire twisted around the two braces as shown then down the side of the neck to be squoze under the hose. Gotta be long enough for the hose clamp to grab them but not stick out under the hose if you care about appearances. Place hose clamp at top of neck to be sure it grabs the wires.



Of course, check the stats in a pan of water on the stove with a thermometer to make sure they're closing and opening at correct temperature first.

P.S. I vote against cardboard in front of the radiator. I've tried it and it's either not enough or too much, especially if your going up and down hills, and have to keep watching the temp gauge constantly and getting out to adjust it. There is no need for it if stats are held in place and working correctly. Drive my car from 0° F in winter to 100° F in summer just fine with the Stant 170° stats shown in the picture with plenty of heat in the winter and plenty of cool in the summer.

[rharv1]

Stats are in place by hoses alone. In the morning am going to run without fan belt for a few minutes to see what that does. Will secure stats just in case they are moving. Then I'm going to restrict tail pipes about 30 percent and see what that does. All 4 stats were checked in hot H2O and work fine.

[jake197000]

dont restrict the exhaust thats not the problem

[alanwoodieman]

I use a 9 x 9 square inch cardboard square and it works perfect

[Straightpipes]

Im up here in the mostly frozen north. The flathead pickup doesnt get put up for the winter. Cardboard works great. Have to experiment with size. Its not rocket science.

[Mr. Will]

Originally Posted by rharv1

Stats are in place by hoses alone. In the morning am going to run without fan belt for a few minutes to see what that does. Will secure stats just in case they are moving. Then I'm going to restrict tail pipes about 30 percent and see what that does. All 4 stats were checked in hot H2O and work fine.

Stats won't stay in hose without something to hold them in place. I used a piece of stainless steel pipe with a hose clamp.

[Tinker]

Who knew cardboard was so versatile. Shop creeper, floor oil protector, engine heater. Its free too, for the most part.

[19Fordy]

Run it without the thermostats and see what happens. Also, check the top and bottom hoses to make sure they are not collapsing.

[tony starr]

and recyclable!

Originally Posted by Tinker

Who knew cardboard was so versatile. Shop creeper, floor oil protector, engine heater. Its free too, for the most part.

as others have said and i've experienced, the stats will move with the pressure of the water from behind, so make sure they are secure.

--

[Tinker]

Originally Posted by tony starr

and recyclable!



as others have said and i've experienced, the stats will move with the pressure of the water from behind, so make sure they are secure.

--

Yes it is, and plentiful supply.

[JSeery]

[QUOTE=rharv1;1424146]Stats are in place by hoses alone. In the morning am going to run without fan belt for a few minutes to see what that does. Will secure stats just in case they are moving. Then I'm going to restrict tail pipes about 30 percent and see what that does. QUOTE]

Hard to believe the thermostats would stay put without something to hold them there!

Why in the world would you consider running it without the fan belt or attempt to restrict the exhaust???

[Snouts out]

That's the nature of the beast! Hot water heaters don't work very well,the original was a manifold type.A thermostat won't help,you need a winter front!

[Joe Immler]

I am in ohio so it's cold. I use a piece of cardboard and it works great.