Thermostat Question

#16

Excellent observation Fogey!

#17

This is starting to make sense.

puffy75 · #18

It would make sense to me also if I felt there was air in the cooling system. I do not.

#19

a agree with puffy. the hole doesn't matter. forget about the mythical air. that hole isn't big enough to let any real amout of ait to escape anyway. i always fill the rad. and then run the engine with the cap off until i have warm water in the neck. after the thermostat opens , the water level will go down. refill to replace the air, put the cap on, fill the overflow tack as needed, and forget about it till nect time. and as stated, i don't think the original honda thermostate had the so called vent

Old Fogey · #20

CYBORG wrote:a agree with puffy. the hole doesn't matter. forget about the mythical air. that hole isn't big enough to let any real amout of ait to escape anyway. i always fill the rad. and then run the engine with the cap off until i have warm water in the neck. after the thermostat opens , the water level will go down. refill to replace the air, put the cap on, fill the overflow tack as needed, and forget about it till nect time. and as stated, i don't think the original honda thermostate had the so called vent

Doug, Just bought NOS thermostat fom Peitsparts, in Honda box with the correct number on it. It has the hole.

#21

"To hole or not to hole, that is the question"

bum · #22

I've seen muscle car guy's who drill holes in the thermostat to allow for some flow before the thermostat opens, I can't remember why. But I also have a problem finding my cell phone, key's and sometimes where I live!!!! 8)

sodbuster · #23

OK ...... maybe this will help settle the question. I found this on a Triumph Web Site .......

puffy75 · #24

Okay now I am looking at a thermostat. I see a (what was it called "A Jiggle Pin") stop tab on the radiator side and a tapered valve on the engine side. This means to me that the device allows fluid or air to flow only one way. If air or fluid are flowing out of the engine that would shut it. I do not think it would be a good vent at this point. If it did not shut the coolant would flow into the radiator defeating the purpose of the thermostat.

However it looks like it lets coolant flow well from the radiator to the engine when the thermostat is closed. I think this is the only way coolant can get in the engine with the thermostat closed (filling position).

Once the air in the engine is released by the thermostat opening, it travels to the expansion tank. That is why the tank can get lower from the first fill up after warm up and cool down then we recheck it's level.

I think the coolant will get into the engine no matter what postion this access hole is, 12 oclock or 6.

What say you guys?

#25

again i agree with puffy....and i have forgotten why we even care about this

dan filipi · #26

sodbuster · #27

WOW .... never imagined that this would turn into such a complicated matter.
I think I found the answer to my original question ...... the thermostat came out with the vent pointing up and that's the way the new one's going in.
Thanks for all the input .......

#28

And I will edit Front Engine Renewal Project to reflect the musings of this panel.

Jiggle Pin Up at 12 O'clock High.

Huhh,huuuhh,huuhh, I said High.

Support our sponsors.

Thermostat Question