Engineer.......... please don't embarrass those of us that actually hold degrees.
Exploding C3 Myths
Racer
Joined: May 2011
Posts: 484
Likes: 10
From: Newcastle NSW
Safety Car
Joined: Nov 2008
Posts: 3,715
Likes: 551
From: Seattle Washington
I recently built a liquid nitrogen cooling system for a scientific apparatus. I did a test where I varied the flow rate through the heat exchanger to see if more coolant flow was beneficial or detrimental. What I found was that higher flow rates were better, period. Unless you are stalling your pump/cavitating your coolant, that is.
Thread Starter
Melting Slicks
Joined: Apr 2009
Posts: 2,632
Likes: 112
From: Great Plains Iowa
I work in the marine industry as an engineer. We use watermakers, which use the hot Jacket water from a diesel engine in a heat exchanger to heat salt water to a boil under a vacuum. The Steam from the Boil is then cooled and the result is fresh water. There is a window in the end of the camber to allow you to look in and watch the boil. I was always of the opinion that the more the flow the better it would boil. Was I ever wrong. It turns out that the slower it is the better. I barely open the throttling valve now. This is one rare situation where one can look in and see instantly the results of heat being exchanged from one source to another. It can go from a simmer to a ragging boil in 10 seconds with a turn of the valve. Since I have found that most Cooling issues no matter what it is is generally to much flow not allowing enough time for the heat to exchange. Its just human nature to think that more is better. I have found not to be true when exchanging heat from one source to another.
Yeah, another engineer with brains! It makes no sense to send 200 degree coolant into a radiator and have it come out at 199 degrees because its being pumped too fast. The coolant MUST pass thru the radiator slow enough to shed heat. A higher volume coolant pump would be beneficial IF the radiator was equally larger but the pump manufacturers aren't going to tell you that. Why? $$$$$$$$$$$$$
As far as the Robert Shaw thermostats go they operate exactly the same as the Stants. A wax alloy pellet forces the valve (or outer sleeve) open against spring pressure. When the wax pellet fails the spring closes the thermostat.
C'mon guys, I want PROOF that my claims aren't true; not assertions.
Melting Slicks
Joined: May 2002
Posts: 2,716
Likes: 121
From: Sulphur LA
St. Jude Donor '05-'06,'11,'13-'14,'16,'18,'19,'24, '25
Yeah, another engineer with brains! It makes no sense to send 200 degree coolant into a radiator and have it come out at 199 degrees because its being pumped too fast. The coolant MUST pass thru the radiator slow enough to shed heat. A higher volume coolant pump would be beneficial IF the radiator was equally larger but the pump manufacturers aren't going to tell you that. Why? $$$$$$$$$$$$$
As far as the Robert Shaw thermostats go they operate exactly the same as the Stants. A wax alloy pellet forces the valve (or outer sleeve) open against spring pressure. When the wax pellet fails the spring closes the thermostat.
C'mon guys, I want PROOF that my claims aren't true; not assertions.
As far as the Robert Shaw thermostats go they operate exactly the same as the Stants. A wax alloy pellet forces the valve (or outer sleeve) open against spring pressure. When the wax pellet fails the spring closes the thermostat.
C'mon guys, I want PROOF that my claims aren't true; not assertions.
I offered post containing information from two of the leaders in the industry (specific to a couple of your statements) but you have yet to counter with any solid information on your part. The two companies quoted in my posts have many years in the specific automotive systems addressed in your statements not in general to the automotive industry as yours.
Neal
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
Melting Slicks
Joined: May 2002
Posts: 2,716
Likes: 121
From: Sulphur LA
St. Jude Donor '05-'06,'11,'13-'14,'16,'18,'19,'24, '25
ADVANCED COOLING SYSTEM BASICS
Stewart Components says;
Common Misconceptions
Coolant temperatures are not an accurate indicator of metal temperatures. The coolant's maximum temperature is it's pressure corrected vapor point. The metal can be several hundred degrees hotter than the adjacent coolant.
Temperatures of critical areas must be determined by checking the metal at a controlled distance from the combustion chamber surface. This eliminates discrepancies caused by the variances in metal thicknesses.
Higher coolant flow will ALWAYS result in higher heat transfer. Coolant cannot absorb heat after it reaches it's pressure corrected vapor point. Furthermore, coolant absorbs heat at a progressively slower rate as it approaches this point
Neal
Stewart Components says;
Common Misconceptions
Coolant temperatures are not an accurate indicator of metal temperatures. The coolant's maximum temperature is it's pressure corrected vapor point. The metal can be several hundred degrees hotter than the adjacent coolant.
Temperatures of critical areas must be determined by checking the metal at a controlled distance from the combustion chamber surface. This eliminates discrepancies caused by the variances in metal thicknesses.
Higher coolant flow will ALWAYS result in higher heat transfer. Coolant cannot absorb heat after it reaches it's pressure corrected vapor point. Furthermore, coolant absorbs heat at a progressively slower rate as it approaches this point
Neal
Last edited by chevymans 77; Nov 7, 2015 at 09:35 AM.
Thread Starter
Melting Slicks
Joined: Apr 2009
Posts: 2,632
Likes: 112
From: Great Plains Iowa
So what you guys are suggesting is we can downsize our radiators to maybe 5" X 10" then blast the coolant thru it at light speed and our overheating problems will vanish? That's really uh "cool".
Race Director
Joined: Apr 2007
Posts: 11,150
Likes: 890
From: South Western Ontario
Being the "ace" you think you are I recommend you contact the engineering departments of all the vehicle manufacturers all over the world and tell them they need to put high volume coolant pumps into their engines. Or better yet I recommend you apply for a job in their engineering departments so you can call the shots. They need "experts" like you.....................
#6 is one of those things that depends on a lot of factors. A broad brush sweeping claim that the statement is wrong is stupid to make because some engine systems benefits from the higher flow pump. I'd bet you money there are C3's out there that require a higher flow pump to properly cool.
However, your theory as to why claim #6 is false is complete BS. I already posted why.
As for the manufacturers, I think they already have a good understanding of how to size the pump to get the necessary flow for the complete engine package they are building. I don't see new cars overheating unless something is wrong with their cooling system.
Melting Slicks
Joined: May 2002
Posts: 2,716
Likes: 121
From: Sulphur LA
St. Jude Donor '05-'06,'11,'13-'14,'16,'18,'19,'24, '25
Neal
Race Director
Joined: Apr 2007
Posts: 11,150
Likes: 890
From: South Western Ontario
The cooling system is closed loop. So, faster coolant has a lower temperature differential between the radiator inlet and outlet.
The cross section area of the radiator tubes for the coolant size and the radiator fins on the air side along with the coolant to air temperature differential dictate how much heat energy it can transfer.
So, you can balance the factors.
Running hotter coolant in the radiator means the radiator is more efficient.
Faster coolant flow means the coolant in the area of the radiator outlet is hotter making that part of the radiator more efficient.
Making the radiator more efficient means less cross sectional area for the cooling air is needed.
But this doesn't mean you can just make the radiator smaller and smaller by increasing the coolant flow. Once the coolant is a fairly uniform temperature, increasing the flow further won't improve the radiator efficiency.
Last edited by lionelhutz; Nov 7, 2015 at 11:06 AM.
Racer
Joined: May 2011
Posts: 373
Likes: 6
From: Dover Delaware
? 4 toobroketoretire..
Every automotive forum has it's myths whether it be Mustang, Camaro, Chevelle, Corvette, or Mopar forums. These myths are started by ignorant people who believe these myths are true but with no evidence to back up their beliefs. Here's a list of the most common myths that you will often hear:
1. Chevrolet hydraulic lifters need to be adjusted "hot and running". That's not true. Chevrolet hydraulic lifters have approximately .150" of plunger travel and it takes 1-1/8 turns of the rocker arm's adjustment nut to center the plunger. The shop manual calls for 1 full turn down from ZERO lash to make the adjustment easy but anything from 3/4 to 1-1/2 turns is fine which makes adjusting them "hot and running" a silly and messy waste of time. Never turn the adjustment nut down only 1/2 turn because that really screws up the geometry of the valve train.
2. 1/2 turn down from ZERO lash prevents valve float and lifter "pump up". That's not true as valve float and lifter pump up is the result of too much rpm for the springs to close the valves. The only way to prevent lifter pump up is to give them several thousands of an inch of lash and the ONLY way to prevent valve float is by using stiffer springs.
3. Thermostats need holes drilled into them. That's not true. The only advantage holes give you is the ability to fill the cooling system a tiny bit faster. But in real cold weather those holes will prevent the engine from warming up quickly because coolant is being allowed to circulate thru the radiator prematurely.
4. Chevrolet engines have "air pockets". That's not true. On an initial fill there are tiny places where air gets trapped but they are insignificant. Once the coolant begins circulating the air gets purged.
5. Cooler thermostats allow cooler engine temperatures. That's not true as once the thermostat opens its up to the radiator and the air flow thru it to cool the engine.
6. High volume water pumps make the engine run cooler. That's not true as coolant must remain in the radiator core long enough to shed heat and speeding it up accomplishes nothing other than making you poorer and the manufacturer richer.
7. Robert Shaw thermostats fail in the "open" position. That's not true as they fail in the closed position just like any other thermostat because the spring forces them closed.
8. Big blocks run hot. That's not true. As big blocks are physically larger than a small block less air gets circulated around them so the engine compartment and interior of the car gets warmer.
9. Distributors need to be shimmed to limit timing fluctuations. That's not true. When the engine is running the distributor gear and shaft are forced upward against the gear's thrust washer because of the helical gears and the torque needed to drive the oil pump. Timing fluctuations are caused by slop in the timing chain and upper distributor bushing; not distributor shaft end play.
10. A dwell meter is needed to accurately set points. That's not true as any dwell angle between 28 and 32 degrees is sufficient to allow adequate coil saturation. On new points a .019" feeler gauge will give the preferred 30 degree dwell angle. As its not a critical adjustment any gap from .017" to .021" will do.
11. Chevrolet engines need 36 degrees of total timing in by 2000 rpm. This is true for drag racing when running 100+ octane gasoline but for street engines running 87 to 93 octane gasoline 30-32 degrees @ 4000 rpm is preferred to prevent pinging. If 36 degrees @ 2000 rpm was needed for street driven cars G.M. would have provided distributors that allowed that.
12. EGR valves cause a loss in horsepower. That's not true because the vacuum-operated EGR valve fully closes under full power.
13. Indexing spark plugs increases horsepower. Yes, maybe 2-3 horsepower under maximum throttle openings but the gain is so minimal its not worth the effort for street driven cars.
14. Starters fail because they get "heat soaked". That's not true but the starter solenoid will lose magnetic strength when it's coil windings get severely heated and that is why the solenoids came with heat shields. Slow cranking is caused by either low battery voltage or a bad electrical connection; usually at the aluminum block-to-frame ground cable.
15. The steel push rod guide plates are for "assembly" purposes. That's not true. The steel guide plates are necessary for all of the 2.02" X 1.60" valve heads because they have a 1-7/8" center-to-center valve spacing; 1/8" wider than the smaller valve heads that use a 1-3/4" center-to-center valve spacing. As cast iron is relatively soft slots in the head would quickly wear out from the side thrust of the crooked push rods.
16. "Figure 8's" are needed after a rear end oil change. That's not true. The factory and dealerships never did figure 8's because the oil and friction modifier soaks into the clutch plates in a matter of minutes and even faster with a single right and left turn. And after an oil change the clutch packs are already soaked with the old oil and friction modifier so there is no gain whatsoever.
1. Chevrolet hydraulic lifters need to be adjusted "hot and running". That's not true. Chevrolet hydraulic lifters have approximately .150" of plunger travel and it takes 1-1/8 turns of the rocker arm's adjustment nut to center the plunger. The shop manual calls for 1 full turn down from ZERO lash to make the adjustment easy but anything from 3/4 to 1-1/2 turns is fine which makes adjusting them "hot and running" a silly and messy waste of time. Never turn the adjustment nut down only 1/2 turn because that really screws up the geometry of the valve train.
2. 1/2 turn down from ZERO lash prevents valve float and lifter "pump up". That's not true as valve float and lifter pump up is the result of too much rpm for the springs to close the valves. The only way to prevent lifter pump up is to give them several thousands of an inch of lash and the ONLY way to prevent valve float is by using stiffer springs.
3. Thermostats need holes drilled into them. That's not true. The only advantage holes give you is the ability to fill the cooling system a tiny bit faster. But in real cold weather those holes will prevent the engine from warming up quickly because coolant is being allowed to circulate thru the radiator prematurely.
4. Chevrolet engines have "air pockets". That's not true. On an initial fill there are tiny places where air gets trapped but they are insignificant. Once the coolant begins circulating the air gets purged.
5. Cooler thermostats allow cooler engine temperatures. That's not true as once the thermostat opens its up to the radiator and the air flow thru it to cool the engine.
6. High volume water pumps make the engine run cooler. That's not true as coolant must remain in the radiator core long enough to shed heat and speeding it up accomplishes nothing other than making you poorer and the manufacturer richer.
7. Robert Shaw thermostats fail in the "open" position. That's not true as they fail in the closed position just like any other thermostat because the spring forces them closed.
8. Big blocks run hot. That's not true. As big blocks are physically larger than a small block less air gets circulated around them so the engine compartment and interior of the car gets warmer.
9. Distributors need to be shimmed to limit timing fluctuations. That's not true. When the engine is running the distributor gear and shaft are forced upward against the gear's thrust washer because of the helical gears and the torque needed to drive the oil pump. Timing fluctuations are caused by slop in the timing chain and upper distributor bushing; not distributor shaft end play.
10. A dwell meter is needed to accurately set points. That's not true as any dwell angle between 28 and 32 degrees is sufficient to allow adequate coil saturation. On new points a .019" feeler gauge will give the preferred 30 degree dwell angle. As its not a critical adjustment any gap from .017" to .021" will do.
11. Chevrolet engines need 36 degrees of total timing in by 2000 rpm. This is true for drag racing when running 100+ octane gasoline but for street engines running 87 to 93 octane gasoline 30-32 degrees @ 4000 rpm is preferred to prevent pinging. If 36 degrees @ 2000 rpm was needed for street driven cars G.M. would have provided distributors that allowed that.
12. EGR valves cause a loss in horsepower. That's not true because the vacuum-operated EGR valve fully closes under full power.
13. Indexing spark plugs increases horsepower. Yes, maybe 2-3 horsepower under maximum throttle openings but the gain is so minimal its not worth the effort for street driven cars.
14. Starters fail because they get "heat soaked". That's not true but the starter solenoid will lose magnetic strength when it's coil windings get severely heated and that is why the solenoids came with heat shields. Slow cranking is caused by either low battery voltage or a bad electrical connection; usually at the aluminum block-to-frame ground cable.
15. The steel push rod guide plates are for "assembly" purposes. That's not true. The steel guide plates are necessary for all of the 2.02" X 1.60" valve heads because they have a 1-7/8" center-to-center valve spacing; 1/8" wider than the smaller valve heads that use a 1-3/4" center-to-center valve spacing. As cast iron is relatively soft slots in the head would quickly wear out from the side thrust of the crooked push rods.
16. "Figure 8's" are needed after a rear end oil change. That's not true. The factory and dealerships never did figure 8's because the oil and friction modifier soaks into the clutch plates in a matter of minutes and even faster with a single right and left turn. And after an oil change the clutch packs are already soaked with the old oil and friction modifier so there is no gain whatsoever.
Very interesting myth post....With regards to #'s 3 & 5 my owners manual calls for a 195 deg TS......All other TS references call for 160 or 180??? Would like your opinion before I head over to NAPA..And I will definitely not drill any holes in it!!!!
mk's78
mike
Thread Starter
Melting Slicks
Joined: Apr 2009
Posts: 2,632
Likes: 112
From: Great Plains Iowa
Prior to the stricter emission controls in the mid '70's the thermostats were 180 degrees. A 195 degree thermostat will assure your engine will run AT LEAST 195 degrees to help it produce cleaner emissions. If you aren't emission conscious I would run the 180 degree thermostat because all of the plastic and rubber components in the engine compartment will last longer.
Racer
Joined: May 2011
Posts: 373
Likes: 6
From: Dover Delaware
OK CF gurus..let's talk....
.....Thermostats...with respect to all of the posts/responses..
My 78's Owners Manual calls for a 195 degree Tstat......Ok Great...
I cannot find any reference anywhere that suggests any Tstat other than a 160 or 180...????
Can any one clue me in as to which one I should purchase before I head over to NAPA???
mk's78
Mike
My 78's Owners Manual calls for a 195 degree Tstat......Ok Great...
I cannot find any reference anywhere that suggests any Tstat other than a 160 or 180...????
Can any one clue me in as to which one I should purchase before I head over to NAPA???
mk's78
Mike
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
Here we go again
For a guy who doesn't understand why his BB Chevy get better gas mileage after putting in a CAI system, you seem to have it all figured out.
And for that matter as recently as May of this year claimed that CAI systems were a waste of money and time.
http://www.smokinvette.com/corvettef...ad.php?t=74409
Yet 4 months later installed one of your own. Hmm could be you are capable of learning still.
I figure you throw out ridiculous claims as a sort of vetting process. You want to see which ones will hold up and which will not. Then you add that to your new repertoire. Then next time the subject comes up you can be the smart guy.
Thing is most of the answers can be found on the internet through reputable sources.
Lets take this one for instance;
I guess what you are saying is that there is no throttle setting between idle and full throttle?
In addition, contaminating the combustion process with more exhaust gas produces no loss in power production? This process does require an ample supply of oxygen to do it's job.
If that is the case then why even have exhaust systems. We could just dump all the exhaust into the intake and be done with it.
I mean really if exhaust gas contains the needed oxygen for combustion of fuel then why do we even need an intake?
It's perpetual motion-like and the induction of a fresh supply of air is not needed for each subsequent combustion cycle after initial start-up.
Wow that's too cool.
And for that matter as recently as May of this year claimed that CAI systems were a waste of money and time.
The gain is so minimal its just not worth the time and expense to convert it over.
Yet 4 months later installed one of your own. Hmm could be you are capable of learning still.
I figure you throw out ridiculous claims as a sort of vetting process. You want to see which ones will hold up and which will not. Then you add that to your new repertoire. Then next time the subject comes up you can be the smart guy.
Thing is most of the answers can be found on the internet through reputable sources.
Lets take this one for instance;
12. EGR valves cause a loss in horsepower. That's not true because the vacuum-operated EGR valve fully closes under full power.
In addition, contaminating the combustion process with more exhaust gas produces no loss in power production? This process does require an ample supply of oxygen to do it's job.
If that is the case then why even have exhaust systems. We could just dump all the exhaust into the intake and be done with it.
I mean really if exhaust gas contains the needed oxygen for combustion of fuel then why do we even need an intake?
It's perpetual motion-like and the induction of a fresh supply of air is not needed for each subsequent combustion cycle after initial start-up.
Wow that's too cool.
Last edited by REELAV8R; Nov 7, 2015 at 01:04 PM.
Pro
Joined: Jan 2001
Posts: 511
Likes: 66
From: Timnath, CO
I wish I could remember the formula from when I sized heat exchangers as a chemical engineer over 30 years ago. What I can remember is the amount of heat transfer is based on the surface area of the exchanger, the thermal conductivity of the fluid, the flow rates of the two fluids (air and coolant in this case), and the temperature difference of the fluids across the exchanger (i.e. air in / out and coolant in / out).
The bottom line is that with a higher flow rate, the coolant temperature drop across the exchanger (radiator) will be less than the lower flow rate case, but the total amount of heat removed across the exchanger will be greater (flow x delta t x Cp heat capacity).
So if you need to remove more heat from an engine to prevent overheating, you can either increase the size of the radiator, increase the flow rate of the coolant, or increase the air rate (presumably with a bigger fan).
The bottom line is that with a higher flow rate, the coolant temperature drop across the exchanger (radiator) will be less than the lower flow rate case, but the total amount of heat removed across the exchanger will be greater (flow x delta t x Cp heat capacity).
So if you need to remove more heat from an engine to prevent overheating, you can either increase the size of the radiator, increase the flow rate of the coolant, or increase the air rate (presumably with a bigger fan).
Drifting
Joined: Sep 2007
Posts: 1,572
Likes: 51
From: Wichita Kansas
To broke
Man you just need to give it up. Maybe just read on here and learn something. I have never read a post from you with any resemblance of correctness. You have made statements on torque converters that are way out from correct. You once mentioned a person never needs a converter with greater than 2000 stall. Some of us have Experance and others don't If information is false it could cause undue added expense. I have been on here for years and have owned and worked on Corvettes for 34 years. I learn something here every time I log in. For the new and less experianced you are grossly misleading. Your information is received with suspect as your integrity is lost
Man you just need to give it up. Maybe just read on here and learn something. I have never read a post from you with any resemblance of correctness. You have made statements on torque converters that are way out from correct. You once mentioned a person never needs a converter with greater than 2000 stall. Some of us have Experance and others don't If information is false it could cause undue added expense. I have been on here for years and have owned and worked on Corvettes for 34 years. I learn something here every time I log in. For the new and less experianced you are grossly misleading. Your information is received with suspect as your integrity is lost
Last edited by Aggitated Monkey; Nov 7, 2015 at 03:44 PM.