I've been having this problem where every thermostat I install eventually gets stuck open. The first two were from Stewart and Mr Gasket. Both of these were shoved open as the first time the car was turned on after installation. The last one was a Failsafe thermostat, and it lasted about a month before it got stuck open. I think I heard the moment it failed. I turned off my car after a drive on a freeway, and after a few minutes I heard a weird sound. The closest thing I compare it to is someone kicking a large metal drum filled with water. After this, 125F is about the hottest I can get it when I'm working the engine really hard. I'm using a 4 core aluminum radiator. It does good job at keeping the coolant temperatures normal when driving through 110F heat. This started happening after I installed a Stewart Stage 1 water pump. This one in particular: https://www.summitracing.com/parts/emp-16133/make/ford Does anyone have any suggestions for the correct type of thermostat? I not sure where I'm going wrong in my thermostat selection. I'm looking for one that's rated around 180F.
Ummm, my thoughts, the additional flow is jamming the stats open. I'd think it would be a common problem, maybe contact mfgr to see if they have a recommended stat to use?
Maybe you have, but I would suggest removing the thermostat and boiling it in some water to confirm it is really "jammed" open.
Yea, like -000%. Air in system causes overheating. Stated in first post he can't get temp over 125* when stat sticks. Ought to be obvious stat is sticking, upon removal if it's still open, it's stuck.
Here's the thermostat Stewart recommends: https://www.stewartcomponents.com/product/high-performance-180-degree-305-thermostat/ Is that what you used first? If so, I'd be talking to them.
Apologies, vs blast that was more of a wet book of matches. Keep this in mind, a liquid cooled engine is not going to run cold because it's low on coolant(air in system).
This is a 1973 302. I have a transparent filter in the radiator hose, so I can catch any small pieces of permatex that come out. I did a big timing chain, water pump replacement in 2018. I had been having overheating problems, so I went to a Stewart water pump and thermostat, and a 3 core aluminum radiator. After the first two thermostats failed, it ran around 160F. I replaced it with a 4 core, and now it runs too cold. I talked to Stewart and they said that my pump doesn't need one of their modified thermostats. I believe the 302 thermostat is 2.125", and they only have a 180F thermostat in 2.5". I'll probably try a Robert Shaw thermostat, since it's the same brand they use and modify.
Thanks for the details. My idea was to see if you had either a roller block with an early style water pump or an early block with a later reverse rotation pump. I was thinking this may have gotten your flow reversed and sucking open the thermostat. Just a thought. Micah
