I bought a new "192 - 195" degree thermostat from Napa and then went home and tested it in a pan on a scientific hot plate and measured the temperature with a laboratory thermometer.
Guess what the results were...
It started to open at 201 degrees and became fully open at 210 degrees.

I think I'm going to go to NAPA and get another one and see if I get the same results. I can understand 2 to 3 degrees off but 15 degrees!

Anyway thought that it was an interesting test.
Matt

 

oem spec is 82C, 180F

 

Thats scary. I think I'll get this one from the dealership..

 

I replaced my thermostat with the Stant one from Checker, my temps went up alot! So I went to the dealer and just got the right one and things are all good again. I don't think I am ever going to buy another aftermarket thermstat for an rx7.

 

the only FD part that's best to buy from the dealer is the stock thermostat.

 

good find, but you must have been bored out of your mind to find that...

M

 

is there a thermostat other than the OEM one that u guys could recommend? something thats opening earlier.

 

I tested the stock thermostat in the same manner and it worked spot on!

 

I tested the thermostat not that I was 100% bored, but I just wanted to make sure. I could not believe it but the stock thermostat from the dealer ship is 180 degree thermostat.
This is a KDRotary rebuilt engine with there 180 degree thermostat. But now that it is getting kind of cold out the engine temps on the highway stay right at about 177 degrees, and I personally think that it too cold.

I went out and bought another 195 degree thermostat. A staat this time and it opened up exactly like the one I bought from NAPA.

Interesting. I may take my thermostat out of the car and test it just to see what it does and shoot from the hip there to see what I should do.

 

Get a stock one man. They work fine.. Thanks for the response btw.

 

Yep, the stock one starts opening at 177F and is completely open at 182 according to the specs, so why people keep asking about a "where to get a 180 degree thermostat" I never understand...

 

This is my first winter with the car, but don't you think that is a little cold to run the car at?

 

I typically drill several holes in the stock t-stat for xtra cooling, takes a bit longer to heat up in winter but it still runs around 180-185 degF. I tried the Pettit 170 degF t-stat but it took forever to heat up in winter. Still ran around 180-185 degF in winter. I guess in Houston TX it doesn't get cold enough to keep the t-stat from opening.

 

While in search of a cooler thermostat for my FD, I called KD Rotary to see what their 180 degree thermostat was about. I spoke with someone that informed of Mazda's switch to a cooler thermostat later on in production. It appears that Mazda first used a higher opening temperature thermostat as OEM equipment in the early RX-7s and then switched to a cooler unit; hence the 180 degree thermostat by Mazda. So, all of the new thermostats that you buy from Mazda should read 82 degrees celcius on the thermostat. Thanks.

Kyle

 

Kyle
You are 100% correct. I stopped by the dealership and they had an 82 degree celcius thermostat. When I told the guy that it was 180 he said there was no way.
Well dude sorry but math doesn't lie.

 

82 Degrees celsius is ~180 Degrees F. It looks like you need to work on your math!

Fred

 

you miss understand my statement. The guy at the dealership didn't think it was 180 degrees. He thought it was 195 degrees.
Matt

 

stant carries the 82C t-stat, no experience with it. I have used and tested stant 1.1 bar rad cap.

 

I made the BIG mistake of purchasing a NAPA thermostat. One month later, blown water seal.

Talked to Atkins Rotary, here in WA, they sell at least a motor a month due to aftermarket thermostats.

The reason? No jiggler valve, (actual name). Atkins has informed some parts suppliers about the difference for rotary engines. None were interested in a disclaimer or note in their parts catalog.

Check out the P/N, it's the same for ALL mazda vehicles.

OEM is the only way to go. 180' is not too cold. Is your heater blowing cold air?

What is your concern? It's takes around 10 minutes to warm up either way. How is 10' to 20' going to make a diff on how your car runs?

Oh yea, all NAPA parts are covered 100%, but only for the part, not the damage that results. So the INSTALLER of the part is responsible for any resulting damage.

 

I've also seen similar experiences with aftermarket thermostats. The worst was a buddy of mine got a Pep Boys thermostat for his '88 Turbo. Worked OK for about a month, then the car started to overheat again - ran consistently at 3/4 on the temp gauge (mind, this is with the old 2nd gen temp gauge that actually works right and isn't an idiot light).

Of course, first assumption is "it can't be the thermostat, I just changed that!". Wrongo.

The Mazda thermostat really isn't too pricey and is VERY reasonably priced, all things considered. It has a very long life, too.

I've seen the Pettit thermostat - I think they just took a Mazda thermostat and drilled a hole in it. And charge $50. Hey, Cam's gotta fund his racing somehow!

Anyhow, there is NO GOOD REASON to get a cheapie thermostat.

Dale

 

Well, I like to worry about my car. Just like most of the people on this forum. I think that I wanted to run a higher temp thermostat was so that the car would get out of warm up mode. Which I thought was 175 degrees... Perhaps I'm wrong. But when I'm driving at 2 am on the highway after twenty minutes, I know that that my gauge doesn't read over 170. I have the sensor mounted right underneath the thermostat.
Thanks for your replies I have found this thread to be useful

 

Well guys by the beggining of next month i'm receiving my new ported engine from Japan. I am using a Billion 68 celsius thermostat, a Sard 55mm Aluminium Radiator, a Feed Air Separation Tank and a Billion Fan Controller.

Do you think that my temperatures are going to be far very low?

 

what year did they change to the 180 deg t-stat?

 

I had good luck with Stant SuperStat® premium thermostats. They use a patented v-notch, non-linear design valve to stabilize engine temperatures and allow the engine to warm up faster. This feature reduces overcooling when the thermostat opens, and overheating when the thermostat quickly closes with the rush of cold coolant, thus reducing thermostat cycling. The advantages of a quicker warmup are prolonged engine life and improved fuel economy and emissions. The heavy gauge stainless steel construction and spring offer longer life and maximum performance.

 

I think it has a lifetime warranty due to the stainless steel construction........... I'll have to check on that back home.