Thermostats

[Bryan]

All,

As some of you are awear I have been running my new engine up from time to time. One thing that is puzzling me is that there are no thermostats in it. When I speak to diffrent people the answers I get back range from there not needed to an absolute must our she will just over heat.

So I thought I should put the word out and see how you all manage in the carriers. I under stand the thermostates live in the top hose's. Can anyone shed some light on what they look like or can anyone supply me with a pair. What are the implications in not running stats. My general concern is that with nothing restricting the flow in the coolent system. the rad efficiency may not be up to cooling the water quick enough. causing it all to get a bit to hot

Any ideas.

Thanks

Bryan

[Lynn Eades]

Yes Bryan you should run thermostats. They sit on the head outlets inside the top hoses. They bring your engine up to proper operating temp. giving best perfomance and long engine life. I understand that with out them your motor can overheat because the water can circulat too fast although I have never experienced this in 35 years as a mech.(most people dont leave them out)
The Ford ones are a bit odd in their construction with a sort of gate arrangement(someone will post a pic.) I have seen standard waxtat themostats ground down at the O.D. to fit in the hose of the Ford. Put them in the right way.(wax pellet to motor)

[Bryan]

Lynn,

Thanks for the that, It sort of conferms my own ideas. I have noticed that if I floor the throttle a lot of coolent flows out of the overflow on the rad. at first I thought it may have been over full but now im convinced its due to the flow rate of the water coming up the top hose's.

I could realy do with sorcing a pair of thermostats Before running it up again.

Can anyone tell me what rating they need to be and were I could get them from. If it comes to it I will machine some housings and fit standard ones which are redally availiable.

Thanks

Bryan

[rob love]

The old time flathead boys told me that without thermostats, you will develop little eddies from the fast flow in the block, which will result in hotspots and cracks. I use a good quality thermostats with a 160 degree rating, and trim the outside edge so it will fit in the hose like the origionals. Here in Canada, stay away from Cdn tire thermostats, they are crap. I use the Ford thermostats which would fit a 351 engine. They have never failed me, even on the hottest of days.
Some of the old ford guys will also suggest just putting in large washers in place of the thermostats to restrict flow, but I haven't found a problem with using thermostats.

[Gunner]

Hi Rob:

Post a part number if you can as I'm getting some overheating problems too.

Having a terrible time with spark... not enough. Changed coils still too weak. I'm seriously considering going to an adapter and a seperate coil.

Cheers! Mike

[charlie fitton]

Did you change the condesner? I learned that one the hard way...

[Gunner]

Hi Charlie:

Had an old bus mechanic over last night. He told me to chuck the carbon core modern wires I was using as they put up too much resistance, change the condenser (again (they're cheap)) and clean the points... he figures that it'll spark right up after that (pun intended!). So I have my worlk cut out for me tonight as I need it running before the Carp Airshow (26-28 Aug) and I'm off to STALWART GOAT land on Sat.

Cheers! Mike

[Jordan Baker]

Wondering what is the best thermostats to get, 180deg or 160deg?

[rob love]

I would recommend the 160° thermostats. The temp rating is actually the temp at which they will close, and not when they open. Because the carrier is a relatively low pressure system compared to today's vehicles, you don't want to be hitting the over 200° temp range that a 180° thermostat will reach. I have seen some 180 thermostats not actually open until 240 degrees. Mind you, these are the low quality ones that you got from Cdn tire. Buy some good quality ones form Ford (use a pair of part number RT350) and trim them down with a set of tin snips so they fit.

[Jordan Baker]

Thanks Rob

Im putting together a list of bits I need to get from Mac's. I'll add them on.

[Lynn Eades]

A quick look in an English manual Says that the system releases pressure at 4.5 psi to 5.5 psi, (it is adjustable with the screw, which should be resoldered afterwards) which means it's boiling point is raised to 228 degrees F.
Nothing shows, in the book, with regards which type of thermostat, but it does say that normal operating temp is between 180 to 190 degrees F.
Each water pump impellor is supposed to move 37.5 gallons of water per minute at 3000 rpm.
I dont know, but I suspect it should have the 180 degree thermostats.
Someone with a parts book should be able to clear this up.

UC F1 states on page P-10, at the bottom, They should start to open at 160, and be fully open at 180 degrees F. so ask the supplier which is correct.
I would always use a wax type thermostat. They usually fail in the open position, and are physically more durable.
A bellows type usually fails in the closed position, and are more fagile. The dangers of chaffing referred to in the text of UC F1 are talking about a bellows type thermostat

[ajmac]

The Loyd parts book suggests part No: 78E-8575-A or 78-8575-B3. It does however say that you will only require 1 off, bloody manuals!
The JobLot auto parts book that I use to order bits from the USA has 11A-8575-A as a 160DegF (71 DegC) unit and 11A-8575-BHT as a 180DegF (82 DegC) version. I guess the HT just implies 'High Temperature' version. I understand that the 71 DegC version was the 'factory' standard post war, but I don't know if there was a difference between the cars and trucks....

[Alex Blair (RIP)]

Originally Posted by rob love

I would recommend the 160° thermostats. The temp rating is actually the temp at which they will close, and not when they open. Because the carrier is a relatively low pressure system compared to today's vehicles, you don't want to be hitting the over 200° temp range that a 180° thermostat will reach. I have seen some 180 thermostats not actually open until 240 degrees. Mind you, these are the low quality ones that you got from Cdn tire. Buy some good quality ones form Ford (use a pair of part number RT350) and trim them down with a set of tin snips so they fit.

When fitting your thermostat pay particular attention to how it fits in the recessed area in the head..make sure that the pocket is well scraped out of any rust or goop..
When you fit the thermostat housing over the thermostat and start your bolts in make one last check with a mirror and a light to ensure that the stat is still sitting down in the recessed pocket and that the housing is going to come down flush with the head..
I have seen the thermostat dislodge from the pocket and slide between the housing and the head and when the bolts are tightened down the thermostat housing cracks..usually taking off one bolt hole lug,.,..
So make sure it is in the pocket before tightening the bolt down.

[Ralph Volkert]

That explains the broken lug on my block! Was wondering why someone would tighten down a themostat housing so tight as to snap a bolt. And no it wasnt seized but it was a Pain in the A$$ to get out!

[ajmac]

Alex, that would only apply to Post 1948 Flatheads with the modern style thermostat housing at the front of the heads though, not the earlier type where the unit sits on top of the hot water outlet in the top middle of each head.

Earlier ones are only held in place by the rubber hose pressing into there circumference. The original wartime type with bellows would have had the bellows section sitting down in the water outlet pipe with the valve up at the top sitting on the end of the water outlet. Modern wax type are shorter so have very little hanging down in the pipe. When mine is rebuilt I am fitting post 1948 water pump impellors whch have a much increased flow rate and dosing the water with water weter, I haven't thought much about pressure caps, the post 48 had 4 Psi, but I am not sure about the truck style system fitted to the Loyd.