i wouldn't go that far on this top topic with shopdog, he got the direction of coolant flow all wrong.



http://forums.corvetteforum.com/show...1431370&page=5

post #87

 

Actually, he got it exactly right. The water exits the engine at the top, right where the thermostat is. That's how the thermostat works --- it keeps the water in the engine block until it reaches operating temp, then opens up to let the water into the radiator for cooling.

Read the earlier posts in this thread.

 

Add to the fact that water and gravity work REAL well together and you get the "idea" behind cooling sysytems.

Up next kiddies - The construction and dynamics of radiators!!

 

Incorrect. Here's a quote from the shop manual which describes the flow of coolant. Page 6-355

 

The shop manual tells you to suspend the thermostat by a wire in a large container of 33% glycol solution. Then heat the solution while monitoring temperature. The thermostat should be fully closed 6 degrees below the marked temperature, and fully open 11 degrees above the marked temperature. (That's what they say, which is contrary to standard industry practice, which says the thermostat should just start to open at the marked temperature, and be fully open 15 degrees above the marked temperature.) But anyway, that's the procedure the shop manual recommends for testing the thermostat. The thermal inertia of the large container of coolant will give you good accuracy.

 

I guess I need to buy a shop manual, lots of good info. You said earlier that the coolant temp sensor is reading too high. How much off do you think it is?

 

no, shopdog got it all wrong, the stat is on bottom, the stat housing is attach to the bottom radiator hose. that is where the coolant from the radiator goes into the engine block. start up / look at your own car if you don't believe me.

 

don't know what book you are reading, c6 ls2, coolant doesn't flow through the TB. you can't be reading about ls2 that is for sure. page 6-355 on 06 service manual is talking about oil tank replacement for 7.0 ls7 engine. once again, hot engine coolant exist upper radiator hose > coolant from radiator enter the lower radiator hose through the stat >engine.

 

Quote:
Cooling Cycle

Coolant is drawn from the radiator outlet and into the water pump inlet by the water pump. Some coolant will then be pumped from the water pump to the heater core, then back to the water pump. This provides the passenger compartment with heat and defrost.

Coolant is also pumped through the water pump outlet and into the engine block. In the engine block, the coolant circulates through the water jackets surrounding the cylinders, where it absorbs heat. The coolant is then forced through the cylinder head gasket openings and into the cylinder heads. In the cylinder heads, the coolant flows through the water jackets surrounding the combustion chambers and valve heads, where it absorbs additional heat. Coolant is also directed to the throttle body. There it circulates through passages in the casting. During initial start-up, the coolant assists in warming the throttle body. During normal operating temperatures, the coolant assists in keeping the throttle body cool. From the cylinder heads, the coolant is then forced to the thermostat. The flow of coolant will either be stopped at the thermostat until the engine is warmed, or it will flow through the thermostat and into the radiator where it is cooled and the coolant cycle is completed.

is this a joke? more theories? this definitely doesn't apply to 2006 C6 LS2 engines!!! i just look up my own service manual, page 6-355? what? must be a joke, nothing on this page or any pages near it is about LS2 coolant system. any one also has the service manual, look it up!!!

 

the material shopdog cut and pasted is on 6-654 for 06 service manual, it is under the "general description and operation"


Quote:
Cooling Cycle

Coolant is drawn from the radiator outlet and into the water pump inlet by the water pump. Some coolant will then be pumped from the water pump to the heater core, then back to the water pump. This provides the passenger compartment with heat and defrost.

Coolant is also pumped through the water pump outlet and into the engine block. In the engine block, the coolant circulates through the water jackets surrounding the cylinders, where it absorbs heat. The coolant is then forced through the cylinder head gasket openings and into the cylinder heads. In the cylinder heads, the coolant flows through the water jackets surrounding the combustion chambers and valve heads, where it absorbs additional heat. Coolant is also directed to the throttle body. There it circulates through passages in the casting. During initial start-up, the coolant assists in warming the throttle body. During normal operating temperatures, the coolant assists in keeping the throttle body cool. From the cylinder heads, the coolant is then forced to the thermostat. The flow of coolant will either be stopped at the thermostat until the engine is warmed, or it will flow through the thermostat and into the radiator where it is cooled and the coolant cycle is completed.

this quote is a general statement which doesn't apply to the ls2 corvette. any one that has taken off the stock TB & intake will know there is no coolant going through the TB, or any one that has done what i suggested to dave pawlowski will know for a fact the upper radiator hose heat up way before the lower radiator hose (which leaves to the stat). in the ls1 days, there are coolant lines that goes through the TB. again,the above quote which came from our service manual is a general statement which doesn't apply to C6 ls2. what i stated regarding the flow of coolant has been confirmed by dave_busch the supporting tuner and dave pawlowski. still don't believe us, just go and take a look at your own c6, you will see the lower radiator hose leads to the stat, then start your stone cold car up and see if the upper radiator does get hot a lot faster or not. you will find the truth instead of listening to someone that has never done it, but just cut and pasted some general info that doesn't apply to c6 ls2 instead.

 

That is verbatim from the 2005 C6 shop manual. The page number won't be the same in a 2006 manual because they split the manual from 2 volumes to 3 for the 2006 model year. Instead of being a smart ***, you might try looking in the index of your manual for cooling system. I'm sure the same, or very similar, text will be found in your 2006 manual.

 

The quote is a general statement, which applies to all GM (and Ford and Chrysler) V8 engine cooling systems. Every last one of them has the thermostat at the point where water leaves the engine and goes to the radiator to be cooled.

Now consider that the thermostat is closed until the engine warms up, so the hose attached to its housing cannot have hot water in it. However, the other hose is not blocked, and good old convection will allow engine water to percolate into it before the thermostat opens and allows water to be pumped through the radiator. So it is no surprise at all that the inlet hose gets warm before the outlet hose.

Once the engine does warm up, though, and water starts flowing through the now open thermostat, the situation reverses. If you were to measure the temperature of the hose connected to the thermostat housing and compare it to the hose bringing water back from the radiator to the water pump (I just went out and did this with an IR non-contact thermometer), you'd find that what you've been calling the lower hose is about 30F hotter than the hose you've been calling the upper hose. (The radiator is a crossflow design, so notions of upper and lower don't have much meaning with respect to it.)

Now even you should admit that water isn't gaining heat flowing through the radiator, so it must be flowing the opposite direction from which you've been claiming, as it does in every V8 engine produced by every engine manufacturer. If you still doubt, pull the water pump and look at how it works. It should be immediately obvious that the inlet is the hose coming from the radiator (the one you call upper), and not the passageways that lead into the block. It can't pump the other way.

 

It's interesting that we can't find a definitive answer on this.

 

It is apparent that being a cut & paste mechanic has its problems.
I'm too old and it is too late for me to actually go and look at my car.

Is it possible to copy an actual page of the service manual and post it. (an actual diagram of the LS2 cooling system)

BTW I though the LT/ LS engines had reverse flow.... what do I know I have been driving Fords all these years

 

tommy, definitive answer can be found by starting the car when it is cold and see for oneself. i will never speak without actual experience.

 

The LT series engines were reverse flow. What that meant was that the water entered the heads first, then the block, rather than entering the block first, then the heads as all conventional pushrod V8 engines do. But the water pump, and the thermostat housing, were simply changed so that the water was still pumped into the engine from the radiator, then exited back to the radiator via the thermostat. GM abandoned that approach with the introduction of the LS series engines and went back to conventional flow starting with the 1997 Corvette.

 

judge for yourself, 06 service manual page 6-622, 6-641 & 6-644 refers to the driver side hose (the one that i been calling upper, since it is attach the radiator higher then the passager hose) as "radiator inlet hose". page 6-623, 6-642& 6-643 refer to the passager side hose (the one that i been calling the lower radiator hose, since it is attached to the radiator lower then the driver side one, also the one that leads to stat) as "radiator outlet hose".

shopdog, i know you will fight to the end to make your point just like the suspension thread. so your last post is no surprise to me. but what GM called these hoses should be black & white as the direction of the flow.
http://forums.corvetteforum.com/show...1481540&page=3

 

Talk about fighting to the end to make your point!

You two are saying EXACTLY the same thing, as follows:

Shopdog: "...it should be immediately obvious that the inlet is the hose coming from the radiator (the one you call upper)..."

Cbrf4i1: "...06 service manual page 6-622, 6-641 & 6-644 refers to the driver side hose (the one that i been calling upper, since it is attached to the radiator higher then the passanger hose) as "radiator inlet hose".

I'm still no expert on thermodynamics, but I do know that the purpose of the radiator is to cool the water. So if the engine is running at full operating temps (thermo is wide open), the hose going into the radiator should be hotter than the hose coming out of the radiator.

 

Just to add more confusion, (or clarification) the service manual calls the housing the thermostat is located inside the "water pump INLET" !
Can someone with an IR thermometer monitor the temps at both inlet and outlet during a warmup cycle? This might settle it.

 

I was thinking the same thing when I read that post. Arguing about symantics is just silly, especially when the meaning and intent was clear from the beginning. Newbie....