Which thermostat and why?

[Whaler]

Hi guys finally got my FE expansion tank and will give it a face lift tomorrow...Wondering which thermostat to use and why.
Our typical summer days can range from 70 to 95 and at 95 to 100 we call those unusual and "heatwave" days.....not typical

I plan on using a large electric puller fan. No pushers...The rad is a nice custom brass 4 core and the cobra nose is well shrouded to direct air thru the rad.

The old timer at the rad shop tossed me a new thermostat and rad cap for my facelift, thinking he had given me a 180, it turned out to be a 160.
(no glasses on) So I would like some suggestions before it gets installed.

TIA!

Tim

PS thermostat housing flange to intake didn't look too bad, a little glass beading should clean it up so..any suggestions on gasket sealant??

[Monster]

Tim,

I have an FE and I run a 170 in mine, the thermostat is there to help get the engine to "running temp" and to help maintain the temp once it gets there this is important for engine performance. When cold the engine circulates water via the bypass with the thermostat closed and when the engine reaches the spec temp the thermostat opens however, it still creates a restriction in the cooling circuit. This is to aid cooling and maintain running temp by slowing the flow through the system which allows the coolant longer time in the rad to exchange heat and cool. Natural air flow will (should) maintain a temp of 180- 200 at speed above 25 on your summer days. Your fan will only work when the car is standing still or at low speeds. It is extremely important to shroud your radiator so that the fan can draw from the entire cooling area (All air passing through the radiator should only exit through the fan opening . Fans that mount just to the fins with no supporting shroud will only cool the area directly under the fan.

For sealant I use Permatex Hylomar HPF (Blue)

Hope this helps,

mike 'monster'

[Bob Putnam]

We also drill a 3/16" hole near the top edge of the thermostat flange so that you get a little flow all the time. This will allow the thermostat to "read" the water temperature a little faster in the absence of a heater. It also allows trapped air to move into the expansion tank.

[ohekk]

I started with a 160..thinking that a lower temp would help avoid overheating at slow speeds.

Having learned that MORE engine wear occurs at the lower temps,
(I knew that, but thought overheating and puking was too embarrassing).

I then replaced it with a 180 from NAPA.

Strange but my water temp constantly fluctuated from approx 175 - 200. I thought of the wear issue and thought...this CAN'T be good....so

I replaced that one with a 180 "Robert Shaw" thermostat and this thing holds steady at 180!

I'd go with a 180 degree Robert Shaw!

Bob P,

I've heard of the hole trick...and it seems to make sense...why wouldn't thermostat manufacturers incorporate this?

[Whaler]

Hi guys thanks for the input...I had a closer look at the 160 and see it already has a small hole at the valve seat edge. It looks to be about 1/8" and I can only see half of it as the other half is covered by the closed valve.

So can I assume 180 is better then?

The 160 would open that much sooner and the the car would not likely warm up as it initially should??

I thought the 180 was the more common application myself, was only concerned about putting it in now, only to tear it apart later for the correct thermostat application.
My oldtimer tossed me the 160 thinking it wa 180 anyhow..I will simply return and exchange it..

I will look for some of that permatex as well

Thnaks

Tim

[Bob Putnam]

Ohekk,

OEM applications almost alway include a heater, which allows some flow past the thermostat.

[Dominik]

ohekk,

those drilled thermostats were available for a while. they even had a little shut-off valve to prevent liquid (or air) from flowing back, sort of used for kids snorkeling equipment (why??)
a british leyland mechanic showed me one.

dominik

BTW: after drilling a small hole we experienced a temerature drop of about 10 F all over.
sort of "a 180 F thermostat now behaves like a 170 F".

[Whaler]

went back today and had my oldtimer look for a 180 thermostat in his collection. No luck as he says these big old jobs are not sold that often anymore. We talked about Bob's tip on the hole and commented on how this old style element did have a small hole in it.( a Gates unit made of brass etc). He mentioned that some dodge vans etc are notorious for airlocks and blown head gaskets. He said so many pay little attebntion to coolant levels these days.
So I paid him for a new rad cap I did get off him.
My expansion tank was in good shape according to him. Later
I proceeded to glassbead it and painted it in a nice gloss black, no dents!

Looking for an element in the higher profile parts store, they would ask what model...LOL I would say how about old ford FE or for particulars, I would say 64-65 T-bird 390 thru 428...they would look at me and snicker. Eventually we came with a Stant unit part # 13478, used aparently on dodges, it is 63 MM 180deg.
I told him that anything with a dia of about 2.5 inches would likely work.
Once home, it sat in the housing fine, so I have followed Bob's tip and drilled the hole as this unit is nothing like the one I had earlier. The old stock item seemed to be a much better quality material construction and it did already have the hole.

Also got some of that Permatex Hylomar...looks like great stuff according to its spec sheet. Although I had to run a file just slightly over the flange, if it's sealing surface was at all questionable because of age and pitting it will likely be taken care of by this product ( a gasket dressing not a gasket replacement)



Thanks again guys

Tim

PS Bob P. I am finding your website to be a watershed of technical info for many of the questions I have regarding my build going forward. When I picked up my 80% finished car last month the builder had not yet completed the build manual...

[CSX 4027]

Go 180 and use a 19-21lb Stant racing cap. You will be happy