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astrops 05-13-2004 06:48 PM

this is odd
 
ok, picked up my 72 chevelle a year ago, just pulled it out for the season, was running a little hot so i picked up a 160 thermostat. As i pulled the thermostat housing off, there was no thermostat in there!!

Should i put this new one in, or what??

BstMech 05-13-2004 06:51 PM

Yes.

jimfulco 05-14-2004 12:06 AM

Yes. That might be why it was overheating.

Pony 05-14-2004 03:59 AM

Most likely that's problem, But, sometimes a missing thermostat points to other problems. In areas with high lime/calcium content in the water, these minerals build up in the coils of the radiator when the local water is used in the cooling system. This acts as a restriction in the system much like the thermostat causing too much restriction and resulting in an overheating condition. Removing the thermostat tends to make the cooling system work kind of ok, not quite right, but ok. Open the cap and look in the radiator, if the coils are clean brass/copper/aluminum looking, all is well and you need a thermostat, but if you see a white/Grey chalky looking deposit on the coils then that is probably why the last owner took the thermostat out. If this is what you have, have the radiator cleaned by a radiator shop, they will tell you how best to clean the rest or the cooling system and then only use coolant and filtered water. :thumbup:

Siggy_Freud 05-14-2004 01:00 PM

How could a car without a thermostat overheat? Lets assume the rad waterpump etc are in good shape. Isn't the purpose of a thermostat to allow the water to come UP in temperature before opening and allowing it to cool in the rad? So if there was no thermostat present, logically that would mean the water is circulating from the get go thus taking a lot longer to get into operating temperature.

That is my understanding of it.

However its a good idea to have one as engines operate best within a certain temp range and the thermostat controls that.

lanierledford 05-14-2004 01:31 PM

I'm kind of old, but when I was just a lad, I had a 40 Ford coupe( which I wish I had now. I changed the old flat head to a 283 power pack, which was pretty hot in 1959. To shorten this, the flat head ran hot, had two inlet from the rad, and two returns from the duel water pumps back to the rad. with the tempastats removed, the water moved so fast through the system it didn't have time to cool. The temerstats slowed it down, and it worked find.

USA1 05-14-2004 01:34 PM

Without a thermostat, the coolant does not have enough time to transfer heat away from the engine, also does not spend enough time in the radiator to sufficiently cool the water before it returns to the system. The thermostat also helps regulate how much coolant can flow as well as when it flows.

troy-curt 05-14-2004 01:50 PM

Yepper, that's how it works.

Troy

__________________
If you don't make mistakes. your not doing anything.

69 ss rs full custom camaro 98 ISCA grandchampion
69 ss rs bb camaro wifes driver
66 Elcamino 350/all dz parts,ac,windows,loaded,my driver
69 ss chevelle bb conv.fresh frame off
26 T sedan street rod

Thom Laybourne 05-14-2004 05:00 PM

TEMP
 
Ah, I do not have a book in front of me, but me thinks that the 160 is a bit low for your Chevelle. What size block you running? All the information is true as far as it goes. But I run a 180 in the 383. As said, it lets the radiator dump the heat better. I would just suggest that you check the temperature recommendation chart. Good luck.

hr41pearl :cool:

astrops 05-14-2004 05:31 PM

thanks guys,

would that be why i am running at around 220 after the 160 install, im running a 350 h/o

troy-curt 05-14-2004 05:46 PM

Check your gage and sender first. I would go with a 180.

Troy

__________________
If you don't make mistakes. your not doing anything.

69 ss rs full custom camaro 98 ISCA grandchampion
69 ss rs bb camaro wifes driver
66 Elcamino 350/all dz parts,ac,windows,loaded,my driver
69 ss chevelle bb conv.fresh frame off
26 T sedan street rod

toddtheodd 05-14-2004 05:58 PM

I had major problems with my truck overheating for awhile. I replaced everything in the cooling system and went with a 130 thermostat. The engine now stays around 140 to 150 degrees at 70mph. I plan on getting a 160 thermostat later. I was just wondering how cool is too cool. I have a 350, and I don't know if the 130 thermostat is too cool, if it is why do they even sell one that low?

troy-curt 05-14-2004 06:04 PM

Hummmm, I've never seen a 130.

The 350 was designed to run it's best at 180-190.

Troy

__________________
If you don't make mistakes. your not doing anything.

69 ss rs full custom camaro 98 ISCA grandchampion
69 ss rs bb camaro wifes driver
66 Elcamino 350/all dz parts,ac,windows,loaded,my driver
69 ss chevelle bb conv.fresh frame off
26 T sedan street rod

32vicky 05-14-2004 10:17 PM

I can see it's time to break out some heat transfer discussions when people continue to say the thermostat is required to slow the coolant flow in a radiator "to have enough time to transfer heat". Absolutely false!

The addition of a thermostat, besides getting an engine up to an optimal operating temperature, will add marginal coolant back pressure in the engine and add turbulence to the coolant flow. The marginal pressure increase will hold the coolant in the liquid state at a slightly higher temperature thereby helping to reduce the potential creation of steam pockets internal to the engine. Turbulent flow is more efficient at heat transfer than laminar flow. Therefore, any turbulence added by the thermostat can improve the heat transfer efficiency of the radiator. So, if someone tells you they had an overheating problem and solved it by adding a thermostat, they added turbulence to the coolant entering the radiator which in fact did improve their cooling system.

As far as flow goes, increased flow in a closed loop cooling system improves the system efficiency (not degrades it). Here's the fallacy in the flow argument: If increasing the flow degraded the heat rejection in the radiator, then it would also follow that the heat absorption in the water jackets would also be degraded. Therefore, the coolant would in fact absorb less heat and actually be cooler. The engine block would get hotter, the combustion chamber temperatures would increase and exhaust gas temperatures would increase. But the engine would appear to run cooler from a coolant standpoint. In fact it doesn't work that way in a closed loop system, increasing the flow improves the heat transfer process.

The net time the coolant spends in the radiator remains the same in a closed system, regardless of flow rates (assuming everything else is equal). Don't believe it? Try this... Let's consider a flow rate where the time through the radiator is 10 seconds. Now let's double the flow rate. It makes sense that the coolant must flow through the radiator twice as fast which equals 5 seconds. Now...since the flow rate is double, the coolant must flow through the radiator 2 times at this rate versus only once at the slower rate. Therefore the coolant makes two trips through the radiator at 5 seconds per trip. This results in the same length of time of 10 seconds.

troy-curt 05-14-2004 11:02 PM

There is lots of ways to add turbulence to the coolant. But the only way you can extract heat from the coolant is with the radiator. Thats the way it's been since the internal combustion engine was invented. The longer it stays in the radiator the cooler it gets.

If your theory was right, we could do away with the radiator and the thermostat, and just add turbulence to the coolant.

Troy

__________________
If you don't make mistakes. your not doing anything.

69 ss rs full custom camaro 98 ISCA grandchampion
69 ss rs bb camaro wifes driver
66 Elcamino 350/all dz parts,ac,windows,loaded,my driver
69 ss chevelle bb conv.fresh frame off
26 T sedan street rod


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