Proper thermostat for 261

[HumphreyMurdoch]

Hey guys, I've been searching around and I can't find the right thermostat for my '62 261. There was a thread on the stovebolt forum where someone thought they had the right part number, but the forum is down at the moment.

Does anybody have a part number or know where I can get one? Previous owner took it out. Thanks!

[TJ's Chevy]

I would check with Langdon's Stovebolt. He might be able to help. If not then Classic Part might sell them. Not to sure...I'll do some checking around. The 261 is a motor that is somewhat hard to get parts for. T.J.

[HumphreyMurdoch]

Thanks you guys! I'll start emailing and calling around.
You're right TJ, 261 is not easy to find some parts for. I've had a couple times where old parts guys, or people in general, either look at me like I'm an alien or argue with me that there is no such thing as a 261.

[TJ's Chevy]

Originally Posted by HumphreyMurdoch

Thanks you guys! I'll start emailing and calling around.
You're right TJ, 261 is not easy to find some parts for. I've had a couple times where old parts guys, or people in general, either look at me like I'm an alien or argue with me that there is no such thing as a 261.

One guy told me he had a 227 inline 6 in his truck and I told him they only made a 194-235-230-250-261-292 for the chevy. Not sure were he got 227 from...unless it was a 216 bored and stroked! LOL!

[NEWFISHER]

When you get the part number for a common supplier like Stant, make sure you cross it into their premium line and get the tstat that stays "open" when it fails.

[cg285]

look at a napa thm155 and see if that is correct

[Dillon Rock]

Can you provide a picture so we can see what it looks like? I had to replace the ORIGINAL thermostat on my 64 and they discontinued the design and there was a special adapter for it I had to get for less than 5 bucks at CarQuest.

[cg285]

www.napaonline.com

[jtrichard]

http://www.napaonline.com/Catalog/Re...Dp%3d3%26N%3d0

[cg285]

put 155 in the napa search

[maxwoof]

That looks like the one that is in my 62 k20 with the 235. When I had it out, I couldn't find a replacement either. Every one I ordered was the smaller 2&1/8" that is commonly available. Even the ones I saw listed for the 261 were wrong.
They have this one on rockauto listed for the 283. The napa buyers guide doesn't show it as for the 261 or 235 either.

[HumphreyMurdoch]

Originally Posted by Dillon Rock

Can you provide a picture so we can see what it looks like? I had to replace the ORIGINAL thermostat on my 64 and they discontinued the design and there was a special adapter for it I had to get for less than 5 bucks at CarQuest.

I wish I could, but the guy I bought the truck from said "I pitched it, cools it better in the summer and that's the only time I drive it.".

But, I've sent an email to Tom Langdon and hopefully he replies with some good news. I'll try and load a picture of the thermostat housing. Sorry about taking so long to reply.

[HumphreyMurdoch]

Originally Posted by cg285

look at a napa thm155 and see if that is correct

I found an acdelco part number interchange and this crosses to a Delco #12T11D and says it fits 1965-66 Chevy and GMC vans and big trucks.

http://parts-catalog.acdelco.com/cat...&parttype=3669

The search continues.....

[jtrichard]

pic and dimensions http://www.napaonline.com/Catalog/Ca...155_0378873468

[jtrichard]

HumphreyMurdoch if you have not seen this you might like it some cool info http://1954advance-design.com/Web%20...gine/index.htm

[1963c-10]

Originally Posted by T.J. MCCAULEY

One guy told me he had a 227 inline 6 in his truck and I told him they only made a 194-235-230-250-261-292 for the chevy. Not sure were he got 227 from...unless it was a 216 bored and stroked! LOL!

Probably a 230 or 250 from foundry 227.

[HumphreyMurdoch]

OK guys, little update. I emailed Tom a while back and he replied with some news!

Beau,
Some 261 engines were used with special (larger diameter) thermostats which are very hard to find. You do not need this special thermostat and can use that standard passenger car and V8 thermostat. To clarify the issue, what size 62 Chevy truck do you have? a 1/2 ton or 2 ton?

Tom

I replied back my truck is a 1/2 ton but no idea if its the original engine or not and sent him some pictures of my thermostat housing. Haven't gotten a reply yet, but at least it's a place to start.

So soon as the snow starts to melt away and we reach temps more than -9, I'll take it off and see what will work in there. If all works I'll write up a little tech article for others future reference.

[HumphreyMurdoch]

Just an update for you guys.

I got the 235 thermostat housing from Tom and it works like a champ! Now my gauge holds steady at 180 instead of 110, has heat now and runs better too!
Other than bolt it on and transfer the heater hose fitting, I had to put a plug in the water pump where the bypass was for the 261 housing. I'll see if I can get some pictures to show this.

BUT, if you go to do this there are a few things to make sure, as there are differences.

The upper housing have 3 different angles.
-Straight up
-pitched forward 10 degrees
-pitched forward 45 degrees

And there are 2 different upper hose sizes.
1 1/2"
1/1/4"

Hope this helps some guys out.

[HumphreyMurdoch]

Ok, here is the bypass hose for the 261 housing.



And here is the 235 housing with the plug in the water pump. You'll have to excuse the silicone, the fitting brought some of the threads with it and it was a bit corroded. That crummy chrome plug and silicone was all I had on me at the time to get me by till I can fix it all properly.