Can anyone give me more info on this thermostat that I found in a 261 long block I just bought? It is standard size, ie 2-1/8" carries 160 opening spec. I tested it in hot water and still works great and shows no sign of deterioration. Was this OEM? Engine was a 1962.
Steve
Last edited by sstock; 06/22/20192:05 AM.
1953 Chevrolet 3100 261 cu inch, sm420, 3.55 rear, torque tube still,omaha orange, still 6 volt, RPO green glass, side carrier spare, all done In the DITY Gallery Video of the 261 running
1964 GMC 1000 305 Big Block V6, sm420, the next cab off restoration
That's a bellows-type thermostat. As the coolant heats up air inside the bellows expands and opens the disc valve. They work best in cooling systems with very low or no-pressure radiator caps. I'd consider a 7 lb. cap to be about maximum for that type of stat and a 4# would be better. Higher pressures tend to make them stick open or closed. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Hmm, thanks Jerry for the info, I have a four lb cap (old original radiator) can you think of a reason to not run it?
1953 Chevrolet 3100 261 cu inch, sm420, 3.55 rear, torque tube still,omaha orange, still 6 volt, RPO green glass, side carrier spare, all done In the DITY Gallery Video of the 261 running
1964 GMC 1000 305 Big Block V6, sm420, the next cab off restoration
As long as it opens at the right temp, go for it. Eventually the bellows gets fatigue cracks and fills with coolant, so they're not as long-lasting as the pellet type. Keep an eye on the temp gauge, as one that fails in the closed position causes overheating. Of course, the wax pellet type stat can do the same thing. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
1953 Chevrolet 3100 261 cu inch, sm420, 3.55 rear, torque tube still,omaha orange, still 6 volt, RPO green glass, side carrier spare, all done In the DITY Gallery Video of the 261 running
1964 GMC 1000 305 Big Block V6, sm420, the next cab off restoration
