Running engine without thermostat for test purposes
#1
Instructor
Thread Starter
Running engine without thermostat for test purposes
Just checking because of the odd nature of these cars. I've done it many times on many other motors.
I'm waiting on a new thermostat. There are no significant issues to run the motor without one? No weird turbulence with respect to the water pump or any thing weird like that is there?
I need to check the rad for leaks now.
Thanks in advance, Steve
I'm waiting on a new thermostat. There are no significant issues to run the motor without one? No weird turbulence with respect to the water pump or any thing weird like that is there?
I need to check the rad for leaks now.
Thanks in advance, Steve
#3
Burning Brakes
Join Date: Oct 2001
Location: Abbotsford, B.C.
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Isn't that without the thermostat, your car would take much longer to warm up? I think a rennlister once posted that his car without the thermostat would overcool and the engine never warmed up to operating temperature in normal low speed operation.
#5
It can overcool, but it can also over heat. If the water doesnt sit long enough in the head to absorb the heat, or in the radiator long enough to cool it can overheat. More than likey you will run cool though.
Mark
Mark
#6
Nordschleife Master
its not to bad to replace it with the water pump still in the car.
I bought the super small, right angle needle nose pliers at Harbor Freight, then ground some nubs into the nose with the mototool. Then get a shop mirror (either one on the little stick, or just any small mirror)
works great with the C clip at any angle.
I bought the super small, right angle needle nose pliers at Harbor Freight, then ground some nubs into the nose with the mototool. Then get a shop mirror (either one on the little stick, or just any small mirror)
works great with the C clip at any angle.
#7
Nordschleife Master
OH, and its fine if you can get the car up to normal operating temp.....but once it starts to get a little hot, shut it down. There will be nothing to keep it from over heating once it starts.
the thermostat keeps the water in the radiator to cool it. With no thermostat, the water rushes through the radiator and doesn't have time to cool.
the thermostat keeps the water in the radiator to cool it. With no thermostat, the water rushes through the radiator and doesn't have time to cool.
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#8
Three Wheelin'
The thermostat circulates water thru the engine only to get it up to temp and opens to allow flow thru the radiator. How does it contribute to overheating?
#9
I think thats what you meant
You are correct, when the water in the engine reaches a certain temp it opens the thermostat and allows the warmer water to enter the radiator, thus allowing cooler water to enter the engine, allowing the thermostat to close which allows the cooler water in the engine to absorb the heat, and the hot water in the radiator to cool down. without the thermostat the water can actually move too fast and not allow any of the thermal transfer to take place.
Mark
#10
Instructor
Thread Starter
Well it certainly ranks in the bullsh*t category of mechanical things, because I had a farm for 15 years and I know all about mechanical BS, but it's all about the snap ring tool. I finally found a Husky "snap ring plier set" for $8.99 at Home Depot that barely reached.
These are the type that come with interchangeable heads (not just the pins). Had to grid a length off one of the handles and some posts on the pliers themselves. Even with doing that the 45 degree head barley reached the snap ring holes. That's the main problem; is that the ring is too far back in the housing. I measured 12 mm from the outside edge of the housing. I'm sure with the Porsche tool it's like a 45 second job.
Anyways, appreciate the responses, motor is running fine on water for now, had it out for a spin and no leaks in the rad.
#11
Nordschleife Master
Yeah, thats the problem with regular snap ring pliers....they're to short.
The little, right angle needle nose pliers with the tips ground down works great cause the tips are longer than the snap ring pliers....and the handles are shorter too. Incase the snap ring is turned in a bad direction.
The little, right angle needle nose pliers with the tips ground down works great cause the tips are longer than the snap ring pliers....and the handles are shorter too. Incase the snap ring is turned in a bad direction.
#12
Nordschleife Master
And yes, Marky is correct. Thats what I was trying to say.
It doesn't make your engine get any hotter, it just doesn't help it get any cooler...... Through the no heat transfer thing.
It doesn't make your engine get any hotter, it just doesn't help it get any cooler...... Through the no heat transfer thing.
#13
The assumption here is that a water pump can flow more water than what is capable of passing through a wide open thermostat, resulting in the thermostat being a flow restricter of sorts. I am skeptical. Anyone a fluid dynamic engineering guru that knows for sure either way?
#14
Three Wheelin'
I was thinking along the same lines as Shiners as to the flow characteristics of the pump vs. the thermostat. Has anyone tested whether in normal operation the thermostat fluctuates from open to close in a cyclic manner. I've been under the assumption that its only use was during the warmup period, which is why most race motors I've seen don't have them, no need, but it takes longer to warm the motor.
#15
Nordschleife Master
It doesn't really work on a Porsche (or anything with the radiator cap on the pressure tank), but on an "older" car with the cap directly on the radiator, you can see the water move when the thermostat opens, and stop when it closes.
It cycles all the time the car's running. Thats also why there are different temps of thermostats. That dictates at what temp the engine will operate at.
It cycles all the time the car's running. Thats also why there are different temps of thermostats. That dictates at what temp the engine will operate at.