Not if I understand post 82 correctly.
Overheating issues
- Thread starter phaelax
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All ^^^ interesting to think about.
The atmospheric pressure of 14.7 lbs. per sq. in. is the weight of our complete atmosphere pressing down on the surface of the earth at sea level.
Fascinating . . .
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Interesting, probably why the 16 psi radiator caps are used.
This allows the cooling system to build pressure to 16 psi to overcome the (push back) atmospheric pressure of 14.7 psi in the vented reservoir tank.
When the coolant is expanding, then it is allowed to flow into the reservoir from the pressure difference between the 2.
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This allows the cooling system to build pressure to 16 psi to overcome the (push back) atmospheric pressure of 14.7 psi in the vented reservoir tank.
When the coolant is expanding, then it is allowed to flow into the reservoir from the pressure difference between the 2.
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You are confusing reference pressures.
14.7 psi is the approximate Absolute Pressure of the atmosphere at sea level.
16 psi pressure on the cap is the pressure difference between the inside and outside of the cap.
But it vents into a closed vessel that only vents at 16 so the system only vents at 16lbs
Think of a water heater over pressure valve
If you cap the open end of the drain line it no longer is an overpressure vent it is a plug.
Another analogy...
If you put a hose on the nipple under the radiator cap and plug the open end of it. That hose will not allow pressure out of the radiator to atmosphere, so it does not matter what the cap pressure is it is plugged and the pressure in the rad will just increase tillt something let's go.
I get it, trust me. We're on the same page. But like it or not, in that scenario, the radiator is still vented.
Explain please.
It will only vent an insignificant amount so for the practical purposes needed for a properly working cooling system it is not vented. Once the pressure is equalized at 7psi between the tank and radiator it will increase in pressure until it reaches the pressure of the cap on the reservoir. Then it will vent like a properly working cooling system is designed to vent.
I'll vent the difference between the 7PSI cap and the 16PSI cap. I guess that's insignificant? Regardless, the radiator is still vented TO the overflow. It's a silly argument, since the example is just that. An example that doesn't exist. Maybe a better word we can agree on is "expansion" rather than venting?
If the expansion tank was the size of a 5 gallon bucket I might give it to you.
That tank was effectively the top of the radiator and had the pressure cap on it
(IIRC)
Thunderbirds IIRC.
My 56 Ford pickup did not have that, my 63 econoline, 65 and 68 mustang either.
The newer cars have a closed system in that the expansion tank has the pressure valve on it. And an air gap to allow for the expansion. As the pressure gets to cap pressure the fluid is well below the cap and only air is expeled or sucked back in.
JUST LIKE MY 67 WITH NO OVERFLOW.
the air gap in the top tank of the radiator tank is sufficient volume to hold the expanding fluid. As the pressure goes up it reaches cap pressure and expels air.
As the coolant cools off the and it's volume reduces it sucks (atmosphere pressure really pushes) air back into the top tank.
Not a drop of fluid is spilled, no overflow is needed.
Bottom line. If the radiator is filled 100% full the expanding fluid has to go somewhere. When the pressure in the rad gets to cap pressure fluid will exit the radiator. If it goes into a closed vessel ( no vent) it will pressurize the vessel in short order and continue to build pressure till something let's loose.
It's not rocket science. But some symantics complicates things.
In one of the OP's posts he stated that his friend confirmed that his "overflow" did not have a vent, and that he was going to reroute his line from the rad to the bottom of the "overflow" and drill a hole in the cap for a vent.
Kitty's 04 Escape is like that. My 04 Powerstroke truck was like that. The overflow tanks in those instances are essentially like the early Fords and actually a part of the radiator.
Still running just the cleaner and water, the car does seem to be doing a lot better. I'm using Thermocure cooling system rust remover. I think airflow might still be an issue however, as the temp climbs while idling in traffic. But cruising around at 45-90 the temp has stayed under 200. I think I will get the radiator filter, had no idea such a thing existed. I've tried removing the block drain plugs but they're stuck pretty good. Any more force I was going to strip them. I talked with my shop to have them try it, but it'll be a couple weeks before they can look at it.
I may be having another unrelated issue now. I think the IAC on the sniper efi is getting stuck. Sometimes at idle it hangs at 1200rpm (idle is set to 820). The other day I was trying to come to a stop and rpms hung at 2k, which makes stopping a bit harder, not too mention how much faster it launches when I take my foot off the brake. It's actually making the car dangerous to drive. The IAC was reading at 50% and only getting as low as 10, way too much. Later that day, it seemed fine. Either something needs reprogrammed or something is broken.
I may be having another unrelated issue now. I think the IAC on the sniper efi is getting stuck. Sometimes at idle it hangs at 1200rpm (idle is set to 820). The other day I was trying to come to a stop and rpms hung at 2k, which makes stopping a bit harder, not too mention how much faster it launches when I take my foot off the brake. It's actually making the car dangerous to drive. The IAC was reading at 50% and only getting as low as 10, way too much. Later that day, it seemed fine. Either something needs reprogrammed or something is broken.
There is a electronic heating device that looks to work well.
More details please.
Induction heating
harbor freight sells one
I have not used one but it looks promising.
harbor freight sells one
I have not used one but it looks promising.
Just an update in case anyone was curious. A few months back I had discount tire flush the whole system out since after several weeks my usual shop didn't seem too concerned with returning my calls. I haven't overheated since. There is still an overflow issue I believe, as the engine does heat up if I sit still too long. I can't remember how high it gets, if it reached 200 or not, and it's hard to test now that winter is here.
Are you using an overflow bottle?
It is normal for fluid to expand as it heats up.
If the rad is 100% full some fluid will move from the rad to the overflow.
(And back again when it cools)
If you are not using an overflow and you don't have the 1 inch air gap in the top rad tank, than fluid will escape out till enough has been removed to create the air gap.
After that you should not have any overflow issues.
ASSUMING all other things in the cooling system are working properly.
On my stock 67 Dart 273 2bbl I keep a 1 inch air gap and have not had a drop come out in 7 years, not even when bracket racing this and last year.
My car routinely gets above 200 when sitting in traffic etc.
I might have mentioned before. If it isn't puking coolant out it isn't overheating. 200 would br perfect for a 195 thermostat.
All this is alien to me. I run a 13LB cap on my 75 F250. I have an overflow tank, but the hose going to it from the radiator rotted a hole in it a while back and I've never replaced it. Even still, the radiator never vents out of the cap. Never. Not even in the hottest of the summer. You simply cannot fill the radiator sloppin full. You must leave an inch or two between the coolant level and the top of the tank to act as an "expansion area" and you will likely never even need an overflow tank. I'm still gonna replace that hose whenever I finally think about it.
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