Thermostat failure Mr. Gasket High Flow

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iScamp

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I put a high flow water pump on the 340 in my Mirada. If you put a high flow component in one part of the system, I think you ought think about the rest of the system. After some research, I went with the Mr. Gasket Co. High Flow thermostat. 132 miles later, the car begins to overheat; fortunately on a few miles from home.

A couple of thoughts on this:
*I don't think plastic belongs in a component such as this.

*We originally were going to drive the Mirada to a cruise-in, Friday, about 150 miles away. But, a few minor things caused us to cancel the trip. Even though disappointed in not going, that decision kept us from a roadside breakdown due to the thermostat.
MrG Thermostat.jpg
 
Apparently, from the valve seat in the thermostat. I don't remember exactly what it looked like when I installed it. Haven't found a decent online picture, yet.
But, if you look at the big piece on the left, you can see the word: HIGH. The radius of the plastic pieces are about the same radius as the top of the thermostat cone.
 
I don't recall seeing those pieces in one but it is possible. I've used Mr G thermostats for years without an issue. I do drill a 1/8" hole in the flat washer part of every stat I use to prevent an air lock when filling the system.
 
I usually drill a small hole to prevent air lock, also.
I didn't for this particular application. ( I just remembered why: there is a built-in bleed hole. You can see it at about the 8 o'clock position in the first picture). Didn't have any problems for the first couple of weeks I drove it. Short hops to get a burger or gas. Coolant temperature was o.k.
I got the thermostat from Summitracing. There were 4 reviews that said the thermostat failed shortly after install. Other online users said it was a good part to install.
I think I will go with an OEM style or maybe the Milodon. Haven't decided, yet.
 
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I've had one in my 69 360 Dart for several years with no problems. And I just installed one in my 68 416 Barracuda.
 
iScamp said:
I put a high flow water pump on the 340 in my Mirada. If you put a high flow component in one part of the system, I think you ought think about the rest of the system. After some research, I went with the Mr. Gasket Co. High Flow thermostat. 132 miles later, the car begins to overheat; fortunately on a few miles from home.

A couple of thoughts on this:
*I don't think plastic belongs in a component such as this.

*We originally were going to drive the Mirada to a cruise-in, Friday, about 150 miles away. But, a few minor things caused us to cancel the trip. Even though disappointed in not going, that decision kept us from a roadside breakdown due to the thermostat.View attachment 1714946762
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I gave up on t stats years ago, Moroso makes water restricters that work way better then any t stat and have nothing mechanical to fail
 
mopar jimmie said:
I gave up on t stats years ago, Moroso makes water restricters that work way better then any t stat and have nothing mechanical to fail
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If all your going to use is a restricter, Just cut the move part of a stat out and install the disc. You don't have to buy anything.
 
I was thinking about restrictors, too, jimmie. Don't know much about them. This car will not be a daily driver but, will be driven year round. Street use only.
More research. I"ll look into a restrictor.

P.S. I just saw a Youtube video and the poster said not to install a Mr. G hi-flo thermostat. Failed on him.
 
The restrictors come in a pack with several different size holes so you can experiment , my 528 Hemi has one in it and works fine with no running hot or overheating issues . I think the pn # 63440
 
I wouldn't use Stant thermostat either. Just got done replacing one that was bad out of the box. Forgot to test it before I put it in.
 
Never had such a failure.
Did have standard Stant thermostats that drifted from temp spec and opened at 160.
Wouldn't be a problem in the south, but when it's near zero fahrenheit, makes a huge diff in heater effectiveness and fuel mileage.
 
Another plug for the Mr Gasket thermostats. Used them for years with no issues.
 
I really think most thermostats get blamed for be defective when in fact the systems have an air lock after install that cause all kinds of problems. This is why I drill the 1/8" hole in the flat disc part of all the stats I install to prevent this.
 
Mine was definitely failure. Put in a pot of water, 200 deg still only open of hair.
 
Heard of these situations,still run one...A "Robert Shaw" is the best supplier,from the old days. as an old parts guy,the Israeli built ones look best,if you need a stat. Personally,you could just cut & gut the stat plate you have,& try it ,as a trial... Seen it work,just sayin'....
 
I too had a similiar incident. Mr Gasket stuck open after a week!! Pure junk! Like Abomber mentioned Robert Shaw stats have been the best so far back say 6-8 years Autozone of all places carried these bought 2 worked flawlessly. I have also heard of Milodon stats. Not sure if they are a good piece.:eek:
 
QuickDart360 said:
I too had a similiar incident. Mr Gasket stuck open after a week!! Pure junk! Like Abomber mentioned Robert Shaw stats have been the best so far back say 6-8 years Autozone of all places carried these bought 2 worked flawlessly. I have also heard of Milodon stats. Not sure if they are a good piece.:eek:
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No problem w/ the stats, but 3 times w/ a gasket. 3 diff kinds of gaskets, 2 diff. housings. this time I went back to the chrome housing, chucked it up in the lathe and machined off the area from the bolt holes out. this created a shoulder for the gasket to seat-before the edges around the bolt touch. used a plain o`riellies gasket, and torqued the bolts instead of tightening them :farm tractor tight" like I always did. think I got it this time.
 
I've used probably 20 of the Mr Gasket ones, including the 383 I just finished. Never had a failure, and at least two were moved from one veichle to another when engine work was done...lol.
 
Just Found a Mr Gasket hi flow stat laying in the clearance rack at a local machine shop. New in the package180° piece. Got it for $5. Gonna put it in tomorrow since I've already got a hi volume water pump and bigger radiator. Guess I'll keep a close eye on temp gauge in case it has any issues. Seen alo t of bad reviews on it also
 
Here's the Mr Gasket stat I was gonna install tonight. How does something like this get packaged and not thrown in the trash where it belongs. Package was in perfect shape and this thing looks like a mess!!!! Glad I only gave $5 for it. Now I can properly dispose of it.
0228172041a.jpg
 
I have a Milodon high flow no issues. It's not the same as the MR Gasket is it?
 
I don't recall there being any plastic in those thermostats. But then again, I haven't bought a new one in a while. Last one I installed has worked fine for 10+ years.
 
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