The Stovebolt Site Forums The Shop Area Engine Shop 261 thermostat housing on a 235 engine

Once again folks I thought I figured out a problem until I read more into it.

A while back I asked about adding a "tee" on my cooling system to add an mechanical sensor to check the temperature while keeping the original sensor for my original gauge in the cluster. The advice I received was first the sensor or sending unit needs to be in the flow of the water and if I add a "tee" it might not sense properly. Secondly, the 261 thermostat house had an extra port for a bypass on the upper thermostat housing. I finally found a housing which was sent to me "paying it forward" from another Stovebolter and here is my question. When I was searching for the part numbers here I started reading about the 261 having a dual acting thermostat that allows some circulation through the engine during warm up that avoids hot spots until the main portion of the T stat opens. So if I connect a mechanical sensor to the upper port on the 261 housing will it read correctly? I have the lower port of the water neck of the thermostat housing going to the heater.

I have a 261 upper and lower thermostat housing that I will be installing an a 1956 235 truck engine. I a "tee" from where the water pump heater hose connects because I am running water heat to the intake manifold.

Any advice is very helpful.

If I am good does anyone have any part numbers that will work for my application?

Here is what I have found just want to make sure I got the correct part numbers.

The application for the thermostat should be off a '62 C60 with a 261 engine. (If the parts guys ask)

Stant 13928 for a 180 degree thermostat
Stant 13926 for a 160 degree thermostat

Does anyone have a part number for the gasket on the thermostat housing where the upper meets the lower?

Tiny

The first question I have is why do you want two sensors? Does the original sensor not work? To tell if the t-stat opened?

Secondly by adding a mechanical sensor you then have to worry about the line getting hit when you do anything on the engine since the line will be in the front of the motor in the way.

Fixing the bad/ broken sensor/gauge seems like an easier solution.

Sweet its a pretty simple question. I want the original gauge sensor working and i want a mechanical sensor that i can read numbers instead of looking at just dots. I never said it was broken.

Wouldn't a SIMPLIER solution be to spend an afternoon with an old thermometer and figure out what temps the dots mean?

Sweet with all due respect i am not here to argue or get into a wizzing contest or try to out think someone with alpha male B.S. i appreciate your opinion however I do not want to do that. i have made my question very clear and i would appreciate that if you do not wish to anwer or do not know and you are trying to take the high road to a problem then please allow someone who may wish to answer my question to help me understad how its different from the 235. I like this site and do not wish to ruin it for me. Besides i like numbers better than dots and i lkke the look of my new gauges and i want the original gauges installed too.

Easy Tiny Jaime, in your first post you said "any advice is very helpful. Good or bad take it for what its worth to you.

I have met and know Sweet personally and he is not a "high and mighty" guy. He is sincerely trying to help... like he has several others. Take it easy, his intentions are truly to help. In the end we ALL know when its our/your truck, we do what we want.

(I couldn't find a big C60 listed)
CHEVROLET 1962 C20 PICKUP 4.3L 261cid L6 Cooling System Thermostat Housing:

FEL-PRO 5021; Alternate/OEM Part Number(s): 1634360010, 25040, 25138, 25148, 740006, 838297

VICTOR REINZ C24529; Alternate/OEM Part Number(s): 838297, 888297

Chill man- hope this helps! It is from Rock Auto, so double & triple check what I looked up-- I'd hate to see somebody drop $0.93 on the wrong gasket!

Brad

Thanks guys. Really i am not bent or picking fights. A while back a year or so ago i was asking about installing a tee to the head where the original sending unit was as i stated and i believe one of the regulars Who comments here like Tim or predave 68 i cant remember who gave me the idea to use a thermostat housing from a 261. That is where this all started. A few weeks ago i decided to follow through with this. After receiving the housing i was really reading the different posts here about the way the thermostat on a 261 operates differently so i was just checking to make sure it works. My knowledge of a tstat is it opens and closes by temp. I saw a 261 pic of a tstat and it did not look like the one in my 235. To cut to the chase. i am not into drama and i really am not mad or even upset. I have read some of sweets post before and i am sure he knows 100 times more than me on these old trucks and have nothing against him or anyone else. In fact i would not mind learning more about these trucks and setting down with you guys and getting skooled. I like the way i am doing my truck its for me. We all build them the way we want wether we do SBC/LS1 or inline, mustang II or straight axle, 4 drum or 4 disc, air conditioning or 2/60 to each is their own. I like positive knowledge not just take a thermometer and label dots. We are all good and thanks if anyone has other part numbers to add i do aporeciate it. Thanks again

I think they are the same as the 235.

Alternate/OEM Part Number(s): 1634360010, 25040, 25138, 25148, 740006, 838297

VICTOR REINZ C24529; Alternate/OEM Part Number(s): 838297, 888297

Those gaskets are for the water neck where the lower thermostat housing meets the block. What part numbers I am looking for is where the upper thermostat housing meets the lower thermostat housing/water neck. Thanks though. I was at NAPA and O'Rielys today and they could not come up with anything other than make your own style.

Tiny_Jaime,

The original 1962 (and other years) 261 thermostat was different from the 235 thermostat.

Different in brand/make (Dole) and a little different in operation, and maybe different in size (I think - maybe - see below).

However, any modern thermostat can be used, as long as it fits the thermostat housing you want to use. The 1960 thermostats started to open at around 160 and were probably completely open at 175-180 degrees.

I cannot find part numbers from 1962, but here are 1960 part numbers:

Harrison Poppet Valve (used on 235s, and V8s): T180

Dole Pellet Bypass (used on 261, and maybe V8s): DV50

Some sources show the T180 as a replacement for the DV50 (indicating that they are the same size)?

Tiny_Jaime

No harm no foul my friend. As Alvin stated, I am here to try to help. Sometimes the "why didn't I think of that" approach is the most helpful.

update....I ordered a t-stat from O Reilly's and it came in damaged it looked like someone cut the brass bushing trying to make it fit something so they ordered me another one. The same day I thought I would try NAPA and ordered me one and at least I figured I would have a back up if both fit. Today I picked up the NAPA one and its part number is 155 (180 degrees F/82 degrees C) made by Stant for NAPA. It fit perfectly. On my way home I stopped at O Reilly's and the second one came in with out the T-stat and the brass ring was bent. Its part number is MotoRad Heavy Duty - Thermostat Line: MCS | Part # 4005-80.

I now see how the t-stat operates with the brass ring or bushing not really sure how to call it. The thermostat is normal and the brass ring had two cut outs where the t-stat meets that allowed water to flow to the upper thermostat housing to the by-pass port and not to the radiator until it t-stat opens and lets water flow into the radiator. My application will work perfectly because the by pass port will be my second gauge port which will be in the stream of the water flow and not interfering with the operation of the thermostat. (yes the mechanical gauge will work and yes I will route the mechanical gauge away from touching any hot motor or rotating parts to avoid any damage).

The only thing missing now is the gasket for where the upper and lower thermostat housing meet. (I can all make one of not available) I have the parts numbers for the gasket where the lower t-stat housing meets the head.

If anyone has the part number for the upper / lower t-stat housing please let me know.

Hey Sweet if you ever into Vegas area I'll treat you to a buffet.

Ok thanks guys

Do you have casting numbers on the upper lower thermostat housing?

I will look. I do not think so i will look when i get home. I searched the stant site but the gasket was for the small housing when i measured it.

The upper thermostat housing is 3757230, x, gm. I gooled the number and it came back as outlet group number 1.153

The lower thermostat housing is 375723(x) x is either a 2 or 3. It was cut off by where on of the mounting hole where cut in so it could not be read. It does not look like a zero. There was not listing on google for the 3757232 or 3757233.

The round water hole on the lower thermostat housing is 2 1/4" water hole opening and where the brass insert or ring that the thermostat sets into the outer ring diameter is 2 17/32". I took it to the well known FLAPS and their gaskets with the 2 1/4" water hole opening is ok but the bolt holes are off. If you look at the 261 thermostat housing the bolt hole is not centered on the 2 1/4" opening because of the by pass port. On the ones from the FLAPS theirs are centered on the 2 1/4" opening.

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