Thermostat FE 406

[Ric S.]

It is time to lite up the engine. In talking to Alan on Friday we discussed thermostats. I am putting a 180 degree unit in. Here is the question. The over the counter unit I bought appears too small for the indented opening of the surge tank. Alan mentioned a larger thermostat before I bought this one. I assume now he meant the overall diameter of the thermostat. If so what kind is that and can I purchase this anywhere?

The sooner you tell me the sooner the fire is lit in another Unique.

Thanks all in advance.

Ric

[brfutbrian]

ric, the thermostat doesnt fit tight in the housing, its slightly smaller (1/8"). if its smaller than that , take the housing to an auto parts place and find a thermosat that fits and get a gasket with glue tape on one side. later , brian

[pgermond]

Brian's correct. The last thermostat I purchased from Napa had a gasket with adhesive on it to hold the unit in place (centered) during installation. I went with a 190 and am very happy with the performance.

[Naumoff]

NAPA 532080 180* t-stat or a Stant 13478

The 63mm fit just right.

It is actually listed for a Dodge.

For the Ford it has to be a Pre 1965 390FE 6.4liter

[eliminator]

Tony is correct, it is for Chrysler Products, go with the 180 degree.

[davebetts]

Why does the preference seem to be the 180, when the 160 is available as well? Isn't a cooler operating temperature better for a big block with no emissions? It also gives a bigger marginal of climbing temperature at the stop lights.
Don't forget to drill an 1/8" hole in the top (12 o'clock position) of the metal flange. This allows the trapped air out much quicker.

[daveg]

Surprised Alan said 180 - swear he said 160 for my 406. I went back and forth and did 160. Climbing temperature was the big reason. Even with the fans, I climb into the 200's on a hot day at just one long stop light.

Dave

[Naumoff]

Surprised Alan said 180 - swear he said 160 for my 406. I went back and forth and did 160. Climbing temperature was the big reason. Even with the fans, I climb into the 200's on a hot day at just one long stop light.

Dave

I just put that fan shroud on and a bigger puller fan. Hasn't gone over 190*F sitting at a light and I have a 180*F t-stat.
Engine performance is better at 180* but if you are not worried about it a 160*F t-stat will be fine. We use to run just a t-stat ring with the center knocked out of it 20 years ago. If it is going to overheat, it will do it with or without a t-stat and no matter the temp. Make sure you have good air flow across the radiator at idle with a Unique.

[Brent]

Well as usual......Rick, Brian, and Tony are dead on.
The thermo is a must have. It regulates the engine temp as well as slowing the water down as it moves through the motor. If the water moves through the motor too fast it does not absorb heat. If the water moves through the radiator too fast it does not get rid of heat. If it moves through both too fast the motor gets HOT.

Why 180 vs 160......A 180 thermostat will build quality heat in the cylinder heads. If you have cast iron heads, 10-1 compression or greater, or a camshaft with a lot of duration or overlap, the 160 or no thermo may work just fine.
But for most people that have aluminum heads, less than 10-1 compression, and a cam with less than 250 deg. of duration @.050, a 180 deg. thermostat will do multiple things.

Keep heat in the cylinder heads and help with combustion.
Regulate temp and equalize temp. through the entire engine
Get the motor warm enough to evaporate moisture (a daily driver needs this less than a "toy" that gets driven now and then)
A cooling system under pressure runs cooler. The #1 issue with "run hot" cars is air in the system.

If you have gone from a "washer with a hole in it" or a gutted thermostat to a 180 thermostat in a FE you know what I am talking about. It will wake up a motor faster than anything.

Oh, and if Allen or Maurice tell you to do it........Do it.

Daveg I am sure Allen looks at who, where, how driven, and what the motor is when he suggests a thermo. Not uncommon for two people to get a diff. answer.

I had a 180 deg. in my FE when we were at Pigeon Forge 3 years ago. At the end of the cruise we hit traffic. Many cars were pulling over, blowing steam, or stressed out. I pulled into the Norma Dan @ 180 degrees.

Have fun!

[ralphscott]

Ditto Brent. Mine was the other cool car at Pigeon Forge. I run a 160, high compression and duration over 250 with Al heads and puller fan. Heat in the combustion zone is key for an effective wave front.

Ralph

[davids2toys]

I am a new Unique Cobra owner, my car is operating art 155 deg,just cruising along, so I am assuming it is a 160deg stat, this is to cold in my opinion, and not good for spirited driving. i am wanting to go with a 180...I have a 428 PI with CJ heads, cam is 314 dur,513 lift...what do you guys think?

[davids2toys]

Would post # 4 and 6 apply to me...and how about that 1/8 hole?

[Brent]

A FE will not run well at 150 deg.
If you build heat to 180 you will swear you added 100hp.

[davids2toys]

I Bought a superstant thermostat yesterday, #45358/180 deg. I told the guy mid 60's 428. Is this going to work?
Also the gasket is just a regular Felpro, no sticky side that i am aware of...do I really need this?
When I do this job I am going to convert the coolant to Prestone "All Makes" from the "Dexcool" that is presently in the system...I am also going to install an ANODE to prevent corrosion.
I do have a Griffin radiator in my car.

[pgermond]

Dave,

The gasket with the adhesive on one side makes it a heck of a lot easier to center the thermostat when installing, but it isn't necessary. As for the coolant, etc.... personal choice IMO.

Good luck.

[davids2toys]

Yeah, I figured that about the gasket, but what about the part # i got, is it correct?
...also, what is with the hole I have to drill somewhere in the thermostat

[JeepSnake]

You want to drill ~1/8" hole near the edge of the stat (not on the flange part that overlaps and seats on the housing, but just a little inside so that it's in the coolant flow). Most anywhere around the t-stat is fine, but when you install it, make sure the hole is located at the TOP. The idea is to have a small bleed at the top of the stat so that as you fill the system with coolant, the air can escape through the bleed hole and prevent air bubbles that create hot spots.

I like to use just a couple of dabs of Permatex #2 (non-hardening type) on the edges of the thermostat to hold it in place while assembling.

I'd help with the part number if I could, but I'm a smallblock guy - DOH!

As usual, Brent's dead on with his comment about going to the 180 degree stat. Changing from a 160 to a 180 in our 351 made all the difference in the world in performance & driveability.

Oh, and welcome to our "Unique" little world! Go ahead and make plans to come to Homecoming next year - you'll love it!

[pgermond]

I don't know if that is the correct part number or not. I walked into Napa and told them I had a Ford 427 and I needed a 180-190 thermostat and they pulled it off the shelf. In an earlier post by Tony Naumoff states - NAPA 532080 180* t-stat or a Stant 13478. The hole allows some coolant to flow and helps eliminate air pockets (?)

[davids2toys]

I don't know if that is the correct part number or not. I walked into Napa and told them I had a Ford 427 and I needed a 180-190 thermostat and they pulled it off the shelf. In an earlier post by Tony Naumoff states - NAPA 532080 180* t-stat or a Stant 13478. The hole allows some coolant to flow and helps eliminate air pockets (?)

I though all thermostats came with a small hole already1

[JeepSnake]

Just depends. I've gotten them with and without. I've even gotten them with a hole that had a little check-valve assembly of sorts comprised of a BB in a tube. Supposedly, air would flow through it, but the extra force from coolant would push the BB into the hole, forcing the coolant through the t-stat itself.

Something else I did - keep in mind this is on a smallblock. Right behind the t-stat housing is an NPT fitting where a heater hose normally connects on passenger cars. Most Cobras that run without heaters simply install a plug in this hole. I used an NPT bushing to adapt down to the size of a radiator petcock which I installed there. Now, when filling the cooling system, I open the petcock to let the air escape. When green starts to run out, I close it, top the system off, and am ready to go.