180* vs. 160* Thermostat?

[Tedderdog]

I am replacing the Water pump and my 1964 Buick Skylark, 300ci, no AC. Since I am doing that, just as well replace the thermostat. I have two choices. 180* & 160*. They both will fit but am wondering what the best choice would be. Much appreciated! Jerry

[BillK]

Jerry,
What was factory ? Probably 180 .... thats what i would use.

[Aaron65]

In my opinion, use a 180...it was factory. A 160 will run you too cool on cooler days.

[Tedderdog]

I appreciate the response and will take your advise and go with the 180*.

[bobc455]

I'll add another vote for 180.

-Bob C.

[paniner]

Contrary to popular belief, the thermostat does not regulate engine heat- doesn't matter if you run a 160 or 180. Your engine, on a normal day with a functioning radiator will operate around 200 degrees. The thermostat opens to allow coolant to begin to circulate from the warming engine to the cooling radiator, keeping it from overheating. A 160 thermo allows the process to start quicker and on an extremely cold winter day may not be advisable for quick warmup. You'd probably notice the difference most through your heater, which would NOT warm up quickly with a 160. Until later cars with their new smog junk and electronic brains, a 180 was almost always recommended by manufacturers- but for more complete combustion cars now operate up to 220, kept from boiling over by higher pressure caps and coolant, along with electric assist fans. Hope this is helpful.

[bobc455]

I believe my car came with a 195 thermostat from the factory - hotter = more complete combustion (better gas mileage, better emissions, etc.). The ONLY time you want a colder engine is when making maximum HP, like on the track.

-Bob C.

[GS455_65]

Prior to emmission regulations most thermostats operated in the 160-170 range as this provided an operating temp that gave the best engine wear rate with a 4 to 7 psi operating system.
When emmisions became a priority, higher temp thermos in the 180-185 range were incorpotated with an increase in system operating pressures of 13 psi or more to provide a larger safety margin before boiling occurred.
Now most manufacturers are using 195 or more to achieve more accurate control of emmissions with system pressures of 20 psi.
An interesting aside to this is that for maximum power an engine operting temp of 180-185 is the best.

[bbatka]

Yes, I agree with using the higher temp thermostat, but make sure you have a good high pressure radiator cap too. the added heat will generate more pressure that you need to keep in the radiator. you don"t want to boil-over!! I've always been told to use a 12-15 lb radiator cap. Not the 7lb ones...
The only other problem you might have is your radiator. Make sure it isn't clogged, it needs to be free flowing. have fun out there!