It was mutual, but the moderator should have had the common sense to shut down that line of discussion, not contribute to the continuation.

what if my slant 6 engine is a 1975 rebuilt but my radiator is original--1964. should i use 190 or 180 thermostat???
and, not to be redundant but how do i confirm the year of my engine? the original engine that came with my car threw a rod about 7 years ago and i bought a rebuilt--best to my recollection--off ebay and i think it was from a '75 van. sorry for my slackness...

It's not so much the year of the engine or radiator that matters, it's the emissions package your car has.

Use the 180° thermostat, Stant SuperStat, p/n 45358.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

From a 1976 Service Bulletin.....

Good TSB post, Craig. This one reminds me of TSBs issued for '60 Dodge/Plymouth and '89-'91 Dodge Ram w/Cummins Turbodiesel to address the same "Customer complains temp gauge reads too high" condition, but the fix in those TSBs was decidedly sneakier: they call for inserting a resistor into the temp sender wire so the gauge reads lower!

(Maybe this technique is a way to run the correct thermostat and have the temp gauge point to "C"...?)

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

http://www.flushmate.com/images/flushmate_videos.swf

I think I just heard a toilet flush!

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I've been calling it as i see it for my entire life and that's not about to change. Take it or leave it.

I remember reading somewhere that the reason for raising the temperature the thermostat opens to 190/195° was to improve unleaded fuel atomization, and didn't necessarily have to do with emissions.

Steve G.

H'm...this sounds like it might've been one of those "Ack, I'm a writer for Popular Mechanics on deadline and I have five column-inches to fill!" explanations, where presence of words takes precedence over accuracy of information. There's truth at the core, but it's a little mixed up and unclear.

Unleaded fuel doesn't atomize any differently than leaded, and high-temp thermostats came in several years before unleaded gasoline. Even so, improved fuel atomization's primary result is reduced emissions. The actual reason for raising the temperature of the thermostat (per Chrysler engineers...also GM engineers, Ford engineers, AMC engineers, and engineers at all the other companies that put in higher-temp thermostats as emission control laws got stricter) was to reduce quenchout in the combustion chamber, which reduces emissions of unburned hydrocarbons and Carbon Monoxide.

Difficulty is, increased combustion chamber temperature increases emissions of NOx. Since all three (HC, CO and NOx) are controlled and regulated, it was a real balancing act for awhile there, messing with thermostats of 188°, 195°, 190°, 192° in different years, trying to keep the combustion chamber temperature hot enough to minimize HC and CO while not heating it up hot enough to push NOx into the problem zone. The balancing act got considerably easier with the introduction of EGR in 1972 (California) 1973 (Fed/Can), for this allowed the specific control of NOx while still running the hot 195° thermostat to minimize quenchout and resultant HC and CO emissions.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.