Rob, that looks like an original type . They came in various temp ranges. I've seen 155 and up

Rob, be sure to check a new one in hot water with a thermo. I bought one on ebay that didn't open even at 212. And then I went to no bypass and normal 'stat. and it goes to 160 and generally stays there winter-summer-A/C-no A/C--but I don't run in a desert nor above Mason-Dixon.

Doug and Richard,

Thank you.
It appears to be designed to work with the internal shape of the neck, where the earlier replacements weren't. It probably makes no difference, but it obviously worked well for a long time.
The one pictured is stuck open, and has been that way for a long time...

Rob

I believe this is a "bypass" type thermostat and was used by Hudsons for many years. Check Ebay, or e-mail some of the vendors who regularly sell Hudson stuff in the WTN classifieds. Dave Kostansek in Ohio, may have some. I think you can find one for less than $10 (I found one in the dollar pile at a street rod flea market, and picked up several NOS ones at a Hudson meet for very little money).

I think there were only one or two variations of these, ever made. Possibly there were different opening temperatures.

Someone will hop in here, and give you some interchange numbers.

[url= http://www.ebay.com.sg/itm/Vintage-Bridgeport-Thermostat-Model-6HT-HUDSON-/291569973572?hash=item43e2ecb944:g:jiYAAOSwZVlXojjF ]http://www.ebay.com.sg/itm/Vintage-Bridgeport-Thermostat-Model-6HT-HUDSON-/291569973572?hash=item43e2ecb944:g:jiYAAOSwZVlXojjF[/url]

Thank you Jon!

Rob

Rob, as has been pointed out there were several types used. The most common was the bypass type as pictured. Be careful though if you wish to purchase on as they came in two varieties. On e was a standard temp model (155 degree) and the other was the hi temp model( 180 degree) For general use the standard model will work just fine. MAKE SURE you get a Hudson thermostat. Many times ones are listed that look like a Hudson by pass type but the lip around the middle of the thermosat is slightly wider. If you use the wider type and tighten down the gooseneck it will crack the "ears" on the gooseneck housing. If you need an origional NOS one let me know. I have them.

Lance,

Thank you.

Can you define "general use"?
I have A/C, and enjoy driving at highway speeds fairly regularly (70+)

Have you started accepting Paypal or credit cards?

Rob

Rob, 'general use is for driving in conditions that would not require a 'hot' thermostat (180 degree). That is, driving in areas when the temp is not below zero for any extended period of time . Lets say like winter in Alaska. Temperate driving is what a 150 degree thermostat is for. I accept your personal check as payment if you are interested in making a purchase. Call 704 seven nine two 9110.

Yes, that is the correct thermostat. If you notice, the top, round portion sticks into a corresponding opening in the housing. This closes the bypass opening when the thermostat opens for metered, water passage through the engine. Make sure the original type thermostat you buy has that or the bypass will always be open. This will allow some of the water to short circuit back to the radiator and reduce cooling

Also, the original thermostats all have their heat range on the box as well as stamped on the thermostat. They are marked high (HT), medium or low (LT)or by degree (155, 165, etc). The 155 was for use with alcohol antifreeze as it boils at a lower temp. The mid temp was for permanent antefreeze (Prestone) and the HT for severe cold. I always use the low temp ones. I figure if it keeps the normal temp at 155 degrees when I hit a hill or traffic jam the water has a longer way to be heated before it boils. Just my though, but I don't have overheating problems with any of my cars. In any case, stay away from the HT or 185-195 versions. I belive they are for severe cold weather use and would need to be replaced with a regular one in the summer. (And who needs to do that every summer)

A lot of people will try to run without a thermostat or put in a modern thermostat and find that they now have an overheating problem. This can also be caused by the lack of control of the bypass as outlined above.

Walt Mordente wrote a great article on the modifications needed to run a modern thermostat and subsequently sold the kits. I have never tried the kit but I know others have with sucess

AC will require the lower temp as the condenser, in a normal installation, dissipates its exhaust heat directly into the radiator. Make sure to stay away from the 185 - 195 version.

Hope this helps you a bit

Lewis,

Thank you!
Your reply is indeed helpful, I am here to learn!

Rob

Just as an added note, the temperature on the thermostat is the temperature it starts to open or close. A 180 degree was used in winter to promote quicker warm ups. A 160 was used in summer. A fully opened thermostat will never be the cause of over heating.

https://www.youtube.com/watch?v=f45kAmjAOYA

Let's try this

Lew

More information than you ever wanted to know about thermostats
check out:
http://www.stant.com/index.php/english/products/consumer-products/thermostats/faqs/

Also: https://youtu.be/f45kAmjAOYA

If the link does not show up, go to YouTube and search for:

Animation How Wax type thermostat works (Must Watch)

it is a great animation showing how they work.

Note; Some older thermostats don't use the wax pellet. They totally rely on the spring metal expansion to do the modulation of the water flow.

Lew

RELATED>> I do need to say that if you are running a water pump pulley larger than 5" in diameter in a step down then you are probably running hot, especially if you are running A/C. Water flow rate will be too low to cool correctly.
I know this from experience. To my partial knowledge the stock pulleys were 5", but with adaptations of power steering, A/C , alternators, and all, the chance of a larger pulley being installed, either double or single, is probable.
I had to take two Ford 6-cyl pulleys, cut on a lathe, and then weld together, to correct mine. Now consistently runs 160 degrees.