The Stovebolt Site Forums The Shop Area Engine Shop I need a thermostat

Hi. I have a 54 Chev pickup. The guy who sold it to me said the original 235 engine had been replaced with an early 60s 261. I checked the block casting numbers on the 'net - its a 58-62 block all right, but a 235, not a 261. Removing the rad hose, I noticed that someone removed the thermostat! So I took the housing down to the parts store and the guy showed me the "correct" thermostat for the vehicle. That one was way too small; there is a lip inside the housing that it can fit against, but no way to hold it against the lip - it would just rattle aroung inside the housing. In an earlier post someone mentioned a "sink strainer" type thermostat. Is that what I need? If so, do you have the part number I need to give the parts guy? Thanks for your help.

I added some pictures to show what I mean:
[img]http://members.shaw.ca/ghillsden/Images/neck.JPG[/img]
[img]http://members.shaw.ca/ghillsden/Images/therm.JPG[/img]

Thanks.

Looks exactly like the thermostat housing on my 261. Go to your parts store and ask for a thermostat for a 261 Viking engine. They were in the heavier duty trucks such as a school bus. Mine came out of a 1960 Chevy School bus Vivking 60. They fit right on a 235. Good luck

Roy Don

If my memory serves me, I believe the one for my 261 (a 160 degree thermostat) was for a '67 Mercedes. Exact fit. Works like a champ.

Thank, guys. That gives me a couple of options to try. Back to the parts store ...

I also have the same thermostat housing. My Local Auto Parts store sold me a Stant #13928. It doesn't look like the old "sink strainer" type I had, but it does fit OK.

I'd be interested to know what you might have come up with.

Steve

Thanks, 53 Therapy. The Stant number you gave me works! Stant also makes a 160 degree version of this themostat. (The last number is a 6 instead of an 8) I will have to make my own gasket though - the parts guy suggested RTV should work, but I have some gasket material on the shelf, so I think I will make one.

Don't forget to drill a 3/16" hole to vent air from the head. This can be a major cause of head failure on startup after refill. New 'stats are almost airtight and the hole is vital to saving the old mill.

Thanks, I will drill that hole!

Pardon my curiousity.... but where do you drill the hole...???

I have the same thermostat issue.... what they came up with is too small for my truck......but I have the old big one to compare.... so it's back to the store....

So the hole... is it drilled in the skirt of the new large thermostat..... because the newer ones are tighter sealing when cold...???

Thanks for your help and advice.

Bob C. :confused:

Yes, drill it in the flange. Search the forum with "drill" and "thermostat" and you will find a lot of discussion about this. I had heard about this because before I posted my question I had made a similar search...

Thanks fellas

Did a search and found out all about he wee litle hole.... will drill mine this week end.

I found that large parts stores have stats in blister packs and damned the part number yoiu can match to size and temp if you bring the stats housing with you....even found a gasket... then I found out the Felcro gasket kit had a stats gasket anyways.

Appreciate your help.

Bob C.

The 261 bypass thermostat does not require a bleed hole.

Forgive my ignorance, but could someone please explain what exactly a "bypass" thermostat is?...and why you don't need to drill the hole? Is it any better than a regular thermostat?
Thanks
Steve

Well I found some thermostat for both the 235 and 261 sizes..... None of the parts store lisitng was any good...so I did it the hardway.

Went to a large Canadian Tire store.... tye stock and display all sizes and style..... I ofund a brand name..."MotoRad".... readily available in the USA... they have a web site......

Now these are regular stats without the fail safe design that some of us would rather not have...

..the smaller one is a model 200 series supposedly fits a number of GM applications It is a dead ringer for the 235 smaller 2 inch mounting...and gaskets were available... total cost gasket and stat..$ 6.25 CDN

On my 261 I will be using the bigger stat a series 268.....both are rated at 180 and 160 and 195 degrees are also available. The bigger one is 2 1/2 inch across.... and has the little bleeder hole with a loose rivet....No gasket suitable with the slightly offset bolt pattern of the 261... no big deal to make your own. BUT the price of the larger size was $23.95 CDN.... according to MotoRad it offers a %60 percent increased flow area.

Hope the information is usefull to others and that my truck will keep a cool head.

Bob C.