Re: Are Sierra thermostats OK?

[Casey Lynn]

These days I usually refrain from posting. Sometimes I just can’t resist debunking a flat-out "wives tale" however.
Yes, you do need a thermostat, regardless of where you are located in the country. After all …where is the cut-off between the "South" and wherever it is that you do need a thermostat? I just looked at a map and don’t see that line anywhere…….
Secondly, the thermostat was designed to bring the engine up to higher temperature (around 130-135F) at idle for a very good reason. That reason being that idle quality can be noticeably increased. Increased smoothness at idle due to the fact that a warmer engine at idle can be leaned more than a colder engine. Leaner engines idle better and do not leave as much unburned fuel on the surface of the water. You do not have a cold block and a hot piston with the increased wear associated with that combination either.
A secondary reason is to keep moisture build-up out of the engine at idle. Moisture build-up is not a good thing on the steel and cast parts of an engine.
Also……What size grommet or restrictor is it that that is being recommended here ??? Will the same size restrictor that will supposedly take the place of a thermostat and restrict enough water to warm the engine at an idle flow enough water to cool the engine at WOT? Don’t think so. Maybe the originator of that suggestion will be there to help you with the costs of rebuilding that engine when you stick the exhaust side of a piston due to an over temp.

Now, to answer the OP’s original question about the aftermarket thermostat. All I can tell you is that Sierra makes points sets that do not line up, carburetor kits that are not complete, and water pump impellers that do not physically fit properly in some engines but some of the guys in here swear by them because they (the parts) are cheap. You apparently get what you pay for so take this advice accordingly.