Thermostat 8 cyl.

pmlmbigpondcom

G'day All,

Have read history of discussion on this subject.

I presume that the attached photo shows a bypass system, and that the thermostat is located in the housing atop the head.

And that the recommended course of action is to seal off the small bypass outlet with a plug ( but with a 1/8 hole in the plug

I also presume that the thermostat flange is sufficient diameter to be located within a recess at the bottom of the housing, with the bulk of the thermostat upwards, within the housing

Does anyone know of current supply of thermostats pls ?

Thanks and looking forward to confirmation or correction of my assumptions

Thanks

Phil
Australia

pmlmbigpondcom

G'day All, Have read history of discussion on this subject. I presume that the attached photo shows a bypass system, and that the thermostat is located in the housing atop the head. And that the recommended course of action is to seal off the small bypass outlet with a plug ( but with a 1/8 hole in the plug I also presume that the thermostat flange is sufficient diameter to be located within a recess at the bottom of the housing, with the bulk of the thermostat upwards, within the housing Does anyone know of current supply of thermostats pls ? OR part No's Thanks and looking forward to confirmation or correction of my assumptions Thanks Phil Australia

bob ward

A Tridon TT2-160 is what I have recently bought for my 8, it fits at the base of the outlet where it bolts to the head. The bulk of this thermostat definitely needs to go down into the head.

Having said that, my outlet doesn't have the bypass connection to the top of the water pump. Someone will be along shortly who knows more about this than I do.

http://www.ebay.com.au/itm/Tridon-Coolant-Termostat-TT2-160-fits-CHRYSLER-AUSTRALIA-VALIANT-VJ-VJ-/252188657012?hash=item3ab79d8574

pmlmbigpondcom

Thanks Bob & Ken

Phil

Per

Phil, The downward side of some thermostats extends too far below the flange to fit. (These will fit fine upside-down, but of course the car will boil since the thermostat will not open!) I suggest that you measure the depth of the space in the head, and check this dimension on thermostats that you find in parts stores. Per

RichardD

I use this high flow one in 308; fits perfectly. Standard one on right side.

 

 

bob ward

What years did Hudson have the plumbing arrangement shown in the photo? i.e. the short bypass between the water pump and the head outlet? 

Did it have a conventional open/closed thermostat or a diverting thermostat similar to that fitted to the top radiator tank on 34/5 cars?

Huddy42

Bob, I have rarely or have never seen a thermostat in any H/T cars I have owned or worked on here in Oz.

EssexAdv

The original is a diverter type, When cool, it allows the flow through the bypass. When warm it closes the bypass and opens the block passage. The original never allowed the pump to try and push against a closed system. It would allow the pressure release through the entire bypass.  The modern modification will close off the bypass as well as the block passage when cold.  Thereby only allowing a pressure relief of the little hole you drill in the freeze plug,  That being said, the 55 and 6 Hornet motor uses a modern type thermostat. It completely closes the system when cool.  Oh, and let's not forget the standard 3x5 doesn't have a bypass at all while the upgrade is a bypass. 

 

So what does all this mean? I donno, I've never figured it out either, So me, I run q 145 degree thermostat of the type the car came with and never have problems.  Well except my overbore 54.  It has a 56 neck on it with a modern type thermostat and water wetter.  no real issues there either.

Frankvintagefullflowcom

The primary intent of the bypass circuit is to maintain coolant circulation within the engine block during warm-up, minimizing local hot-spots and allowing a more uniform temperature rise. It also provides flow through the cabin heater from start-up as a creature comfort advantage (warm air sooner). Centrifugal pumps, as are the coolant pumps in almost all auto engines, "unload" at shut-off......meaning that if you block the outlet path, the pump goes into cavitation which requires less power to turn. It takes more effort to move coolant in one end and out the other than it does to simply move it around in the housing.  The small hole is a vent to prevent trapping of air in the upper reaches of the block/head during the filling process.

The bypass type was used on the upper end 8 cyl. models, but was adaptable to the sixes and lesser models by changing the pump body, T-stat housing and T-stat to the appropriate versions.

My two-bits worth....'til proven wrong.

F  

pmlmbigpondcom

G'day All and thanks

Per, are you saying that if upside down the thermostat will not open because it is not "in" hot water ?  I would have thought there would be sufficient heat transfer for it to open fairly readily - maybe just a short time later than normally.

Anyway, thanks again to all.

Phil

bob ward

This is a photo of a 34/5 diverting thermostat vs a Tridon TT2-160. The 34/5 has 1" hanging below the flange, the Tridon 13/16".

Re installing the thermostat upside down, that is what I would label a Brave Call, but there should be no need to.

Frankvintagefullflowcom

Inverted would be a bad idea. A thermostat must be able to react quickly to temp changes.

F

Jon B

Back to the original question:  Phil, are you asking what the original-type thermostat is, for a bypass type setup such as you have?  (I may have misinterpreted, and you are actually asking how to turn your system into a NON bypass system.)

If you want the original type thermostat, it would be of the brass type, as illustrated in this Ebay auction. In this case it's a Harrison #3121276, but a number of companies made them, and they're not that hard to find if you snoop around: 

http://www.ebay.com/itm/New-1948-52-Hudson-Thermostat-150-degree-/191698081276?nma=true&si=J763p5erLdlXbl7SC8WNflI4%252FF8%253D&orig_cvip=true&rt=nc&_trksid=p2047675.l2557

Here's a photo:



Over the years I've collected several of them, sometimes paying as little as a dollar apiece.  In my log book I've written some parts numbers, but I'm not 100% sure these are all for the bypass type, or for the standard type (non-bypass systems).  If you google them you may see a photo and will then know instantly if they're the bypass type or not:

Autostate 65-FHT-170-175
Harrison 3121276
Gates 33036
Sylphon (Fulton) #65F
Bridgeport 4HT, 6HT
Dole BPH (160 degree)
Standard X034D
Hadees H65-HT (170 to 175 degree)

Hope I interpreted your question correctly.

pmlmbigpondcom

John

Yes thanks

Phil