VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1929-1932 thermostat.....

Did the 1929 6 cylinder engine have a thermostat and if so what temp range? Thanks

The thermostat was an accessory item. However, in colder climates a thermostat was usually installed for winter driving. The original thermostat range was around 140-145 degrees.

my 1929 had a thermostat housing on it as well

1929 Thermostat Housing

Water Neck on Left, Thermostat housing on right
there is a recess in the thermostat housing, as well as a recess in the water inlet on top of the head

1929 Engine with Thermostat Housing Installed

What about 1932? There is no recess in the housing as far as I can tell. I have also read that there should be no thermostat installed if the car has a heater.

If there is no recess then use two or one thick gasket and a modern thermostat. The thermostat should have a very thin edge that will be covered by the gasket and not leak. What you read is NOT correct. If you have a heater you for sure want a thermostat to produce hot enough water for the heater to be effective.

Thanks guys. Much appreciated. (This chat site is a huge help for a greenhorn like me!)

Gentlemen, Thank you for the good information and comments. Turns out my 29 does not have the thermostat housing and with no heater will run without one.
I agree with Bertus, this site has a wealth of information for those of us fairly new to the early Chevrolets. Thanks

I am not disagreeing with you guys BUT the 1929-1932 parts book I have clearly states on page 5 with regards to Thermostat Unit (part 348933) "Do Not Use with Hot Water Heater". Just wondering what the logic would have been for this back then.
Also - I have noticed some cars have a thermostat housing (I believe) Installed below the Water Outlet (part 836272). I just have the water outlet bolted directly to the engine. I have the thermostat installed and it seems to fit OK . Is a thermostat housing required?

You are right as my parts book says the same. Not sure what the reasoning was but a thermostat is best to get the temp up quickly. I think a 160 degree is best. The thermostat adapter housing is not necessary as far as I am concerned. I have had various adapters and have settled for a thermostat with a thick gasket and standard water outlet. The original stats I believe were taller than what is available now so perhaps they did not fit with the standard outlet. Some adapters go between the head and outlet which raises the height available for the stat. Some adapters also have a threaded port for heater hose connection in addition to raising the height of the standard water outlet.

The thermostat unit that the parts book is referring to is the thermostat spacer that goes between the water outlet and the cylinder head. That set-up was used when an original thermostat was required for cars that are in colder climates. This is not to be used for the hot water heater because a special large two piece (upper and lower) thermostat housing is used for the hot water heater. The two piece thermostat housing that is used for the heater has a bypass valve and the thermostat and it is completely different than the small thermostat spacer that is used for non-heater applications.

Check out the issues of the 1931 and 1932 Chevrolet Service News for more information. Also, look on page 127 of the 1929-32 parts book to see the listing of the thermostat and the upper & lower thermostat housings that are used for the hot water heater.

You can use a modern thermostat directly between the water outlet and the cylinder head if it fits, however a special spacer was designed to be used between the water outlet and the cylinder head to give clearance for the original 140 degree thermostat when it was installed.

The spacer was used in 1931 because the thermostats had a large brass bellows to operate the valve that required more space under the outlet. The thermostat housing used with the heater had a bypass that the spacer did not have.

As I have mentioned previously I have a 1932 parts book (February) and it is not the same as the one you use (August) so perhaps Bertus is using the same one I have . It does list 348933 Thermostat Unit with no illustration and specifies in bold print (DO NOT USE WITH HOT WATER HEATER). I have the 31 service bulletin (Sept 1931 Vol.5 #9) that illustrates the heater installation but no part numbers are listed for the heater kit or thermostat unit or bypass valve though a good description of how it functions is there. I am still curious what a 348933 Thermostat Unit is as I am guessing it is the bellows type thermostat and the reason it says not to be used with a water heater is because the heater kit contains a different thermostat housing (two piece) with the bypass valve. My 29-38 book list 3053255 hsg,therm,upper,29-36 and 3053265 hsg,therm, lower,30-36. It also list a spacer ,therm,29-33 #348903.

The Thermostat Unit 348933 consisted of the bellows type 140 degree thermostat and the thermostat spacer, which was used for cars that did not have the accessory Chevrolet hot water heater. With the accessory hot water heater installed a completely different set of upper and lower radiator outlets were used. In this situation, the original water outlet (goose neck) that was used with or without the Thermostat Unit was discarded when the two-piece upper and lower radiator outlets were installed for the accessory heater.

I have a fitting for the side of the lower rad hose to allow attachment of a heater hose. Any problem doing this with just the standard water outlet?

Fitting the heater hose adapter in the lower hose, hooking up the HOT water hose to an adapter at the rear of the head should circulate at least warm water through the heater. There is also a thick plate with hole for water pipe to connect hose for hot water that will fit under your outlet. I have one around here somewhere. It will allow installation of a thermostat and also route HOT water to the heater.

I live in southern California, and had a boil over issue with my 29. The great folks here recommended that I remove the thermostat, I did remove it, and my problem was over. I seem to remember that the associated conversation included someone telling me that a thermostat not needed except in cold country..

Hi Chipper. Would you have a picture of "thick plate with hole for water pipe to connect hose for hot water"? It might make for a better connection than coming off the side of the hose.

I believe the "adapter" Chipper mentioned goes under the water outlet hsg and is used in place of the fitting in the rear of the head for the temp gauge sender. The hose fitting adapter is still used. The lower fitting is the cold water return and the top the hot water outlet. If I am incorrect I am sure Chipper will correct me.

I have a fitting for the rear top of the head that will installation of the temp sending unit and a heater hose. And I have a fitting that will attach to the side of the lower rad hose . That should give me the circulation I need. Was just wondering if the "adaptor" Chip mentioned would be a better idea.
Thinking of installing a shutoff as well. It should go at the top rear of the head (hot water)?

Not sure how you could add a shut off to the rear of the head other than an inline shutoff. If it were mine I would put an adapter under the hose outlet in front with a shut off and maybe another shut off inline on the lower hose. A 3/8 PT to 5/8 hose shut off is a fairly common item and the thermostat adapter is about 3/4" thick and has enough room to be tapped 3/8" pipe if not already tapped. Chipper or JYD might have a different idea.

Looked through my old parts box and found parts 3053255 and 3053265 upper and lower thermostat housing. Apparently these were to be used with cars with a heater. However neither is tapped for a heater hose connection. Checked parts book page 127. It shows 3034086 (tee) and 3034081 (nipple) and 120063 (elbow) for hot water heater. Where are these installed? Also shows 3053251 thermostat, hot water heater. Is this a special thermostat to be used when car has a heater? Also 3053274 valve assembly. Is this installed inside 3053265 in the bypass opening beside the thermostat?

A few months ago on this forum we had a detailed discussion regarding the accessory Chevrolet hot water heater, the upper and lower thermostat housing, the two different thermostats and etc. We also suggested to refer to the September issue of the 1931 Chevrolet Service News for detailed instructions on installing the Chevrolet hot water heater and the related parts.

1. The upper and lower thermostat housings were used with the accessory Chevrolet hot water heater.
2. Neither are tapped for a hot water heater hose connection because one hose went to a nipple on the lower radiator hose and the other went to an elbow fitting on the back of the cylinder head where the temperature gauge is connected.
3. The nipple was installed on the lower radiator hose. The elbow and the Tee were used on the cylinder head.
4. 3053251 is the thermostat that was used when the accessory Chevrolet heater was installed.
5. 3053274 is the by-pass valve assembly that was used in the lower thermostat housing.

For more info. you can do a search on this site to see all of the previous discussions that we had on the 1931-32 Chevrolet accessory hot water heater.

Checked the September 1931 service news. Good instructions but it does not mention the thermostat or the bypass valve. Recommended stat is 140 degrees. Filling station sold me theirs and it is 180. What gives? I have not found any listings for the bypass valve. Is it available anywhere?

The by-pass valve was part of the upper and lower thermostat housings. The by-pass valves are not available so you will probably need to have a machine shop make one.

The thermostat and etc. came with the complete hot water heater package.

The Filling Station sells both 160 and 180 degree thermostats. The 140 degree thermostat was discontinued by Chevrolet years ago.