Thermostats

[mhagie]

the other morning on the way to work with old blue I noticed the temp took over 30 miles to reach 190* outside temp 30* and since it had a RS 370-195 stat it was obvious that stat was hanging open.
No RS stats are available anywhere around at that temp I am aware of.
went to Autozone picked up a 195 stat and changed it out,brought it up to temp and found that the range on stat was to open at 210* back down to 195*.
Would not accept those numbers so went and exchanged it for another one, same thing 210* down to 195*.
Found a RS 370-180 on the shelf and tried it now temps are 180* rock solid stays within 2-3 degrees.
This goes to show that all thermostats are not created equal.
Gave up on the 195, truck will be parked for the winter at first snow anyway.
Merle

[john8662]

What you've described is exactly what I've observed with other stats.

The RS stat is consistant, in that it opens and maintains the temp that it's rated at. So it, probably opens before it's rated temperature and, but only partially.

The other style stats seem to stay closed until right at or after their temp range, so we see the wild swing in temperature, which makes me nervous! This is probably mainly due to where the temp sender is mounted, at least on my engine, it's in the cylinder head. So the temp seen at the head is likely higher than the crossover temp. So, the stat could be opening at 195, but that temperature is at the crossover.

I like the RS 370-180's!

[CleviteKid]

The Mr. Gasket Thermostat, #4367, is a clone of the RS 370-180, and is available from Summit Racing and other fine Hot Rod shops. I only use the RS 370-180 or its exact clones in my truck.

The #4367 is NOT the standard size GM thermostat used in 99% of spark-ignition GM engines. It is the same size as the standard Chrysler thermostat used in V-8 engines of the '70s, '80s and '90s. The earlier version of this post had the wrong Mr. Gasket part number in it -- I have corrected it to #4367 for consistency.



Dr. Lee :cool:

< edited after the Great Server Crash of 20 Dec. 2005 >

[ 12-21-2005, 04:07 AM: Message edited by: CleviteKid ]

[mhagie]

Just for informational purposes I am reading temps at the heater hose outlet on crossover, just added a tee and installed mechanical sender there.
I would believe it to be fairly accurate as it is fed by both banks of cyls right behind thermostat.
Merle

[mhagie]

An observation, I have run a digital temp gauge located on drivers side at rear crossover plate, I have noticed that it runs consistantly 10 to 14 degrees colder than at front crossover temp.
Why? It is my belief that water flows thru block from front to rear then up thru cyl head on its way to front and the crossover/t/stat.
Following that path temps would increase as it flows picking up more heat progressivly from each cyl collecting at t/stat housing where both sides of block/heads are mixed and exited thru crossover.
Sounds impressive anyway.
Merle

[jaymanaa]

What a coincedence. This is my first day as a member and I was going to ask about t-stats. I noticed my temp was hitting 210 and then swing way down. I tried a couple stats and settled on a murray 180. It is rock steady but I am a little concerned about acids and sludge at this temp. I change oil at 3000 so it is probably not a huge concern. What do you guys think?

[CleviteKid]

I have run the 180F thermostats since 1991, with no problems. I don't remember anyone complaining about sludge and acid in the oil due to 180F thermostats.

Try it, you'll like it.

Dr. Lee :cool:

[Trevor Besson]

Hi I was wondering if anybody new what year of jacket water crossover do you need to use to work with the Mr Gasket #4364 thermostat I bought one today and it is way to small to fit the bore of the crossover I have now.

[john8662]

Hmm, what is your truck?

I haven't personally checked the number posted above, but from the looks of it, it's supposed to be the same as the 370-180 which would work in virtually all the 6.2's that are V-belt driven.

[Trevor Besson]

My truck is a 1984.The thermostat I removed yesterday was 64mm dia the Mr Gasket 4364 is way smaller than that so just a heads up to others.

[Portland Suburban]

I got the mr. gasket one today of the real diameter (would the real t-stat please stand up? ;) )

I plan to put it in soon. Anyhow, I wonder why is says "for race only vehicles that will never see street use"?

[BobND]

Originally posted by Portland Suburban:
Anyhow, I wonder why is says "for race only vehicles that will never see street use"? A modern computer controlled GAS engine needs to get to a certain temperature to go "closed loop", and run at max efficiency, so most, if not all of those run a 195 degree thermostat, and the EPA doesn't want you putting a cooler thermostat in, and screwing up the emissions, hence the "race only" warning.