Dan Wendling

Another consideration:

Changing to a high performance 4 core radiator from a stock 2 core radiator would roughly reduce the flow in each tube by 50% but it increases the total length of the tubes since there are 2x as many. So in the net little to no improvement in cooling is made on the coolant to radiator heat transfer interface. However, the radiator has twice the air to radiator interface surface. So a high performance radiator provides most of its improvement in cooling by the larger air interface.

Note most high performance radiators also have improved tube and fin shapes so some performance gain is had in those areas.

..

For those that think that the coolant can pass through the radiator too fast.

Dan Wendling

This article is geared to the lay person. Provides a reasonable summary of the issues.

http://www.arrowheadradiator.com/14_...utomobiles.htm

AORoads

I'm too much of a "layman" to understand all this, but maybe just as an experiment, you might like to change out one thing at a time and see IF you need the next item, i.e., change out the water pump for one w. higher flow, keeping everything else the same. It may just be that's enough. Or, do the radiator change without the water pump change.

dennis50nj

i know all you guys come from an educated background, you all have your theories, I'm just a dropout, but my personal experience's and years of racing on a limited budget has led me to believe that a higher flowing water pump wont make your car run hot, it can close your stat not designed for the highflow pump, and that will make it run hot. you need a highflow stat, also if you take the stat out, then the water will flow threw the radiator to fast not allowing enough time to cool, hence the reason for the sale of
#16420

WATER OUTLET RESTRICTORS
In race applications these Water Outlet Restrictors, on Chevys and Fords, replace the thermostat. They work to slow the flow of coolant through the block and radiator which allows more heat to be absorbed from the block and more heat to be released through the radiator. In cases where the engine has excess cooling capacity, as in an alcohol burning engine, a higher amount of restriction is required than the thermostat, while open, can provide. This kit contains restrictors with 1", 3/4" and 5/8" openings to allow tailoring to your particular application.

Outlet Restrictors -
Chevy, Small & Big Block and Ford, All (except pre '67 390-428)

the 1/4 mile is pretty flat too

Xwet

Moving more water than whats necessary is a robs HP.

glass slipper

http://www.stewartcomponents.com/tec...ech_Tips_3.htm
http://www.stewartcomponents.com/tec...ech_Tips_6.htm

These guys disagree with you...and they have a lot more experience than all of us combined.

CyberGS

Dude, your answer is in your OWN POST. What seems to be common sense ain't so common in some cases............
Why is the HIGHER restriction required to REDUCE volumetric flow in an alcohol burning engine? My guess is you have never worked on an alcohol burning car or have any clue... but I have Yank the thermostat out and let just a stock water pump flow at its rated gpm at idle and THE FANS WILL NEVER KICK ON.

We literally worked on a dirt modified in a hotel parking lot in Bakersfield CA in 115 degree heat, engine idling for over an hour and the temp never got over 150 degrees, TEMP WAS TOO LOW. The fans never kicked on because the switch was 180 degrees.

SO YOU RUN A RESTRICTOR TO REDUCE FLOW SO THE WATER CAN HEAT UP.

So yeah, now that I think about it, the OP is right, there are cases you can run the water thru the radiator too fast... when you want things to get hotter. Reduce the water flow to zero and even an alcohol burning car can overheat

For our gas burners, you can put too big a pump into a system, but the issue isn't that it is flowing too much coolant, it is that the rest of the system isn't capable and at some point cavitation makes it way back from the restriction to the pump. Some backpressure is good, the more restricted, the more the flow is reduced and at the restriction cavitation ensues, at some point in a closed system the cavitation will make its way back from the restriction to the pump and the whole path is just churning and making bubbles.

Dennis,
As for the common sense idea that water boils pretty much no matter what given enough time (referring to the stove top post), got a simple one for you... Instead of posting, get a thermometer, put some water on the stove, turn the heat on low and get the water to a steady state temperature of 180 degrees. Then come back and post how long it took to boil after it reaches steady state and I am talking steady state, just enough heat input to hold the water at 180 degrees, then wait for it to boil.

And I am dead serious here, prove to me you aren't full of crap (and also wouldn't be from this dimension) and that temperature always increases even with a steady heat input, and at a heat input that holds water at 180 degrees steady state, steady state isn't real and given enough time the water will reach 212 deg and boil.

dennis50nj

sounds like mumbo jumbo to me to sell a product, their stat they are selling is a high flow stat and it is a restrictor, once the pressure builds in the radiator how could there be a suction side and a pressure side it is a closed system, why would you need a cap at all. all the posts from other sources wont change my mind of my own first hand exsperiance, milodon has been in the buisness for 53 years

dennis50nj

all your engineer degrees scientific theories and wont change my mind and hopefully some others who will have this problem. of course your double talk of how long it takes to boil, that doesnt have a cooling unit, and it wont reach the 212 in the 1/4got to go its been fun boil away

Dan Wendling

It is a big world and we have plenty of room for each to have their own opinions and beliefs.

Good thing about it is that both sides know the other side is wrong and we all sleep better knowing we were right.

Man I love the Corvette Forum !!

CyberGS

man, I could have save a boat load of typing! Thanks for those links... say exactly what I have been saying.

This leads into the question about cfm in fans pushing thru an evap - forgot to touch on this, sorry.

Dennis probably still uses 4-core 1/2" capillary radiators too and swears by them while the rest of us use 2 core 1" cap dual passes and wonder why our cars run so much nicer and cooler. I have a good story about that - I too fell for "conventional wisdom" with a 1970 Mustang I had and had a custom built 4 core radiator done when I really hot rodded the engine and increased the heat generation. That car would NEVER run cool at slow speeds or idle regardless of how many fans I had on it (I had two electrics pushing and the stocker pulling)... after 4 years, living in SoCal nonetheless and knowing every back street to keep the car moving, a radiator guy told me I needed a two row.

What? All my buddies that had been racing since 1971 swore I need four cores!

But then he explained to me how the new core tech worked, and me being one to learn v. assume I know everything because this one dude told me something or I thought I understood it, I listened. We made a deal (and I was a poor kid mind you) that I would pay him to build the custom rad but if it didn't work he had to give me my money back.

I put the new rad in, fired the car up and let it sit in the driveway idling while I washed it - completely impossible before - then, blown away, I waxed it! It never got over 190, the thermo was 180. I had spent 4 years fighting that car, listening to the masses, instead of the experts.

Cooling tech has come a LONG way since 1971. In fact, the largest reason why guys saw issues with cooling in race cars back in the day is the pumps were built for a car that were to get groceries and at 7000 rpm sustained on a road course, they were cavitating and completely inefficient. I replaced many an impeller on both Ford and Chevy race engines with fully enclosed, "wild" looking impellers to get rid of cavitation and the cars would run like a dream on the track. The flow rate wasn't increase or decreased, just removed the inefficiencies.

The reason why the four core didn't work is the same reason why one poster asked how putting a bigger fan on an evap can cause things to heat up... the evap can't flow the air, so the air just cavitates, everything becomes inefficient, and the lower cfm fan works better as it better matches the core flow rate.

Proof: If the poster were to take an evap and put a really low cfm fan and it will heat up, go a little bigger it gets a little cooler, little bigger.... so on and on but you will notice a point of diminishing returns and a bit bigger does virtually nothing to the temp until all of a sudden it starts to heat back up again. Bigger is better right! Nope, the fan is now in a closed system that has too inefficient for the fan itself and you drive the fan into a state that makes it worth less. The four core rad was such an inefficient core design that the air couldn't get thru it! The real answer why my 2 core worked better wasn't the cap size and quantity but because the core between the caps could FLOW MORE AIR with LESS PRESSURE pushing it.

So the car would cool down at higher speeds because it FORCED more air thru the core by ramming the radiator into the air at 50 mph... the fans couldn't generate the force required to do that so the air just churned in front of the radiator when stopped in traffic.

Education is key to everything, and trust me, I get to learn something new nearly every day at work. I can remember the first time a senior thermal guy told me about tripping flows with maze like passages - blown away, but having an engineering background and knowing the math, it made complete sense and has worked for me every time. Turbulent flow baby!

IN THE END ALL THAT MATTERS IS WHAT WORKS... I the real world and math can be two different spaces. BUT the theory of how things work is constant tho' - so if your car runs cooler with a thermostat or a restrictor, it is NOT because flow was reduced and water spent more time in the radiator, it is a function of restriction, which is back pressure. So while you may have stumble bumbled onto something that works better in your system which is fine and dandy, you may not actually understand why it worked.

Aerodynamics will take these kinds of discussions to a whole new level. They way I mess with aero on my race car is to change one thing, take lap times, change that one thing a bit more and less and take lap times, etc and then after I go thru various items I start the loop again to see if I can maximize a change later down stream going back to the beginning item. I can understand why something works as an individual item, but the car is a SYSTEM and without accurately modeling the system, you just have to try **** and measure the lap times to see if it got better or worse.

Racers just try **** like running a Tstat v. not, putting a smaller rad back in, so forth and find what worked best with the overall system, then start talking out their a$$es about the physics of why it worked. You don't have to know anything about thermal dynamics if you can test the system... it just won't necessarily be optimized but it will be, as I said before, good enough.

CyberGS

Proving that sometimes conventional wisdom is correct... "You can't teach an old dog new tricks". Nor do I care to, do whatever you want to your own car.

All that education and science can't trump my beliefs! Where have I heard that irrational mumbo jumbo before.................... I love that his stove somehow has a cooling unit and that the cooling unit somehow causes his water to boil now that is double talk and but good to know you have yet again proven me right as you have a cooling system on your stove that would boil water for you at 180 degrees Probably should remove the restrictor.

And I don't give two ***** nor have mentioned the 1/4 mile at all, YOU DID you dumba$$, so don't put your ignorant words into my mouth. That is some classic double talk right there.

And when Stewart has info on their site, they are "just trying to sell something" but Milodon apparently hasn't been saying things to sell stuff for 53 years apparently.

Chumps, you will always have 'em.

Dan Wendling

Clearly we both F1 and ARCA fans posting on the web.

Good thing about the United States is that you dont need a license to buy a Corvette just need one to drive it.

dennis50nj

you dont need a 4 row i always used a 3 row from a lincoln or tbird side tanks in my mustangs a good 429-460 clutch fan and ofcourse the shroud, im going to say the OP asked if a highflow water pump would flow to fast, and im going to say no, but on some cars i have seen it overheat with the tstat out and i think that was why it ran hot because the circulation was too fast not staying in the rad long enough to cool, not being caused by a higher flowing pump, and racers on a limited budget try anything and find what makes there car fast for less money, i have done a good job on my car hence the #1 spot of bolt/on c6, and it runs very cool

dennis50nj

you can teach and old dog like me new tricks you just haven't yet, but I'm sure if i read enough of your posts i will, i have read many of glasslippers posts and have learned much, so i will keep my eye on yours and do the same I'm sure, for now i will stick to my previous post

dennis50nj

Dan Wendling

Glad you are taking the loss so well.

dennis50nj

i dont feel i loss, under the condition i said i will stick to it, any car i ever owned ran hotter then normal once more power was added, and i always brought them down to where i get the best time, my c6 runs only 181 at idle and as low as 158 on a warm day, it actully ran cooler with the stock water pump over the ewp going down the road and the track

dennis50nj

well here is another site, that says the same as me, so should i post 100 more, now who's links are more credible, i would say neither, but like i said before I'm not going off of the information from links on the web, mine is first hand experience
http://www.2carpros.com/how_does_it_...ostat_work.htm

Dan Wendling

It is not your experiences that are in doubt it is your understanding of them that is in doubt.

I think we can agree to disagree.

Just remember that years ago all but one person knew for sure that the world was flat based on their experience. Science and mathematics prevailed and most everyone now knows that the world is not flat.

PS> It isn't round either.