Can anyone tell me anything about the following:
"careful and don't get a water pump with to much flow or the water will not have enough time in the radiator to cool prior to going back to the engine"

That's BS. There is a good web site that talks about that. Do a search on Stewart Water Pumps and read their tech section. Also, the was a link posted to an Indiana Car Club web site a couple of days ago that gave a good rundown on fact -vs- fiction in cooling. I think it was on a thread about radiatiors from a couple of days ago.

The web site is www.inccn.net/techforum.htm (http://www.inccn.net/techforum.htm) The thread was "4 core vs 3 core radiator". Its a good read on what works and what is a myth in cooling.

This is an interesting topic, in that my friends dad, who owns his own shop, is doing a top end rebuild on my 67. He is a conservative mechanic. He suggested I replace my water pump and harmonic balancer, and in the process I wanted to get a better flowing pump. He said don't bother because the fluid can only run through the temp valve at a certain speed anyway, and if the fluid runs through the motor too fast it doesn't gather heat efficiently and carry it to the radiator. Any thoughts on this? I guess he isn't a big believer in these "high flow" water pumps....

thanks


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67 Coupe 327
Edelbrock performer package, TH350, Hotchkis suspension & sway bar, Dynomax headers and exhaust, Cowl hood

That quote needs more info before it can be dispelled or affirmed! I know you are posting on our sister site. Was this part of a response to a question over there? What was the context of the entire conversation that lead to the statement you quote?

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...Dennis
"The '69 (http://chevelles.com/showroom/ww.jpg), the '96 (http://www.camaroslimited.com/graphics/memcars/96ss.jpg) & the club (http://camaroslimited.com/)"

As far as the stat, manufacturers of hi-flow pumps recommend hi-flow thermostats. As far as a Stewart pump, I tried their Stage II aluminum (approx $150) for one of the 69's (350). It didn't fit worth a damn.

First, I had to grind the edge of my timing cover to clear one of the 'legs' of the pump, then fab a spacer for the bolt that attaches the alt bracket to the pump.

Then when I got finally got the pump mounted I found three more problems. The pump pulley stuck out 3/16 of inch further than my crank pulley, the heater hose nipple was pointing in a direction that made my heater hose lay on the edge of the alternator bracket.

The last straw was, my lower radiator hose rubbed on my 8 inch balancer. There wasn't enough clearance between the outlet and the balancer for hose.

Terrible. I took pictures, then took it back to my speed shop who replaced it with a no-name alum pump which fits perfectly, and cost 2/3's the Stewart product.

Fyi

[This message has been edited by Sleepy-69 (edited 07-05-2002).]

i am not, nor do i claim to be, an engineer of any sort. but, if you think about it, the water would have to "hang around" in the block for a little while to pick up the excess heat energy from the engine. it would also have to "hang out" in the radiator to get rid of the same heat.if it goes too fast, it won't pick up as much heat, and a "boundary layer" of water might build up on the rough cast iron surfaces of the block, similar to the air that builds up around a car as it travels forward. that would tend to insulate it, i would think.
if more flow didn't kill heat transfer, how come cars can- and usually do- over heat with no thermostat installed? i have seen many overheating problems due to mechanics that thought a t-stat was not necessary.

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1971 Nova(looks like 69 camaro from underneath!)
355sb, vortec heads, HOT cam,T-10 tranny, 3.70 gears 16X8" IROC wheels. 12" Corvette brakes on the way.
see pics here http://community.webshots.com/user/novaderrik

good points novaderik. Your takes sound legit to me. That is right around the same philosophy as my mechanic's....

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67 Coupe 327
Edelbrock performer package, TH350, Hotchkis suspension & sway bar, Dynomax headers and exhaust, Cowl hood

When I put the new engine in my Camaro eight years ago I left the thermostat out. The car seemed to run hot all the time, onced it warmed up. A friend who had a radiator shop told me to put a thermostat in because the coolant was flowing too fast. This sounded idiotic to me but I put in a 160* thermostat and it's been working fine ever since. Just my 2 cents.

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'69 RS Camaro
355 5-speed 4.11

[This message has been edited by 1 2RUN (edited 07-07-2002).]

Actually, the more flow you have, the better. The thermostat helps the system build pressure which raises the boiling point of the coolant which prevents steam pockets from forming. I think that I also read somewhere that the thermostat puts turbulence in the coolant which prevents layers of coolant with different temperatures from forming. When you remove the thermostat, you get alot more flow, but there is not restriction to make the system build up pressure. Here is a good write up explaining all of this: http://www.grapeaperacing.com/GrapeApeRacing/tech/coolingmods.cfm

Just as proof that high flow water pumps work, I have a built (400+ hp), .040" over 400 small block. My cooling system consists of a Milodon high flow cast iron water pump, a high flow 180 degree thermostat, a 5 blade clutch fan with shroud, and a regular GM 21" wide, 2 row radiator. The same radiator that came with the original 307. My temperature gauge sender is in the cylinder head. Right now, in this 90 weather that we are having, it idles at 205-210 and cruises at 190-195.

A high flow water pump is superior to the stock design. It provides more flow, more evenly across the cylinder banks, and also cuts down on water cavitation induced by the impeller. I would highly recommend purchasing one for any engine that has been changed from its stock configuration for the sake of making more horsepower.

[This message has been edited by Cameron (edited 07-07-2002).]

Here's Gary Penn's, GMPP Engineer, opinion on waterpumps.
http://www.chevelles.com/forum/Forum4/HTML/006819.html

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The Red Beast http://www.geocities.com/casanoc

I am certainly no expert, but I know most dirt track racers use a restrictor ring in place of a t'stat. This leads me to believe that more flow is not always better. too small of a hole in ring will overheat. too large of a hole in ring will also overheat. Been there... done that.

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69 Camaro Z28 "clone" - 327 AT
"461" camel back heads,
edelbrock , hooker, ultradyne cam, stewart,
TRW etc.
Vintage Air
700R4 TPI transmission

[This message has been edited by TJS69 (edited 07-08-2002).]

A waterpump does 1 of 3 things...They pump water, they leak, or they completely fall apart.

The thermostat is a temperature regulator. It allows the engine to get up to operating temperature quickly which pays dividends in durabillity, efficiency, and drivabillity. If you leave it out... the engine, oil etc will be running cooler for longer to warm up which increases engine wear and hurts economy/drivabillity while it is doing the extended warm up. The temperature will be unregulated so the clearances will vary along with the temp causing extra wear. The tuning will never be optimum except at the temp you actualy tuned it at so at other operating temps the engine will make less than max power. Steady operating conditions will allow you to tune it in and it will stay in tune. If you do not get the engine to 180-190 during long term operation the oil will be contaminated by the extra crud that did not get pulled out by the crankcase ventilation system.

You should actualy run a 180-190 thermostat in a street engine. It is not as much of an issue for a track engine.

-Mark.

I just ran into the same problem as Sleepy-69 with the Stewart water pump. Mine was a long style Stage I and once it was bolted up my crank pulley and water pump pulley were 3/16" out of alignment.

I called the March Performance tech support dept. and they had me check the measurement from the block to the hub on the pump. This dimension is supposed to be 6 15/16" of an inch. Mine was just over 7 1/16". I then called Stewart and their support people are on vacation until July 15th. Figures. And I took the week off to install the engine. Guess I will be buying a different pump from someone else ASAP and return the Stewart.

jgreen,

Don't give up hope. The hub is likely just pressed on the shaft and is not seated on a shoulder. If this is the case you can press the hub farther down the shaft until you get the distance you need. You will need to remove the back cover and support the shaft when you press the hub. This must be done or eles you will damage the bearing. Be sure that all of your other accessories will also work with this new dimension.

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The Red Beast http://www.geocities.com/casanoc

[This message has been edited by CarlC (edited 07-08-2002).]

Ok Guys,

I am an engineer and I'll have to chime in here.

The more flow the better.

Heat Transfer can be defined as the following:

Q=MCp(T1-T2)

Where
Q= Heat Transfer
M = Mass flow
T1 = Temperature in
T2 = Temperature out
and Cp = coefficient of thermal transfer

For water Cp = 1
Assume a 10 degree drop across the radiator (T1-T2 = 10)

As you can see, the higher that M is (coolant flow), the higher your heat transfer will be).

Therefore you can run more hp (more heat to reject) with a better flowing pump.

Hope this clears it up a little.
Kel



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North Texas Camaro Club (http://www.northtxcamaros.com)

Is the glass half empty or half full???.....Neither, the glass is twice as large as it needs to be!

Carl,

That's pretty much what the March tech guy said too, but I'm hesitant to do that without getting the blessing from someone at Stewart first. If they weren't on vacation until next week I could get it taken care of right away and get on with the project. I'm going to call again in the morning and see if someone else there can't take care of it. Thanks for the suggestion.

I deal with equations also. In the heat transfer equation you presented deltaT and flow are coupled variables so it is not entirely obvious.

I think to approach it to first approximation you would need to solve two coupled dif eq's representing heat and heat transfer at the head and at the radiator. I would guess that this would still result in more flow=more cooling but haven't done it.

I've always thought that the 'remove the thermostat--reduce the cooling efficiency' idea was a myth but have heard many testimonials to the contrary. Perhaps it is all due to the increase in pressure as earlier stated.

I am an engineer too. I use to design cooling systems for nuclear vessels and now do it for various applications, including autos. I AGREE WITH KEL. He has it right. The more flow the better. The website that was given previously www.inccn.net/techforum.htm (http://www.inccn.net/techforum.htm) is my website.

If you don't want to believe me, take it to the best performance engineer in the business Howard Stewart. His site is www.stewartcomponents.com (http://www.stewartcomponents.com) ...go to the cooling system basics under tech...it's spelled out there as well.

The reason a thermostat taken out doesn't perform as well is because it induces laminar flow into the radiator creating a mixing issue. This causes a loss in efficiency in the radiator. The water doesn't turn over or get mixed. The thermostats create turbulence to create more even heating and cooling. My web site covers and debunks these myths.

Gary at GMPP should look for another profession,...he may be a good saleman but his take is wrong for the most part. HIs statement per the thread that was posted prior was "Where do you guys come up with this stuff? How would an aluminum pump better distribute water side to side? What difference would it make that the housing is cast from aluminum?THIS STATEMENT IS CORRECT...way to go Gary Basically, most aftermarket water pump claims are BS. Some claim that they move more water, but fail to recognize that they flow water through the same thermostat. The thermostat is typically the restriction in the system, as it should be. Because water moving too fast through the engine won't absorb enough heat. Also, water moving too fast through the radiator will not reject enough heat."IF ANYTHING, THIS IS THE BS STATEMENT...THIS GUY DOES NOT KNOW WHAT HE IS TALKING ABOUT....AT LEAST BY MY THERMODYNAMICS TEXTBOOK

His statement about some manufacturers claims could be somewhat correct, but the thermostat issue is moot. The restriction builds pressure and actually helps the preventtion of hotspots and increases the boiling or corrected vapor point of the coolant. Have you ever turned on the faucet half way...and then all the way. More pressure and more flow. Same thing on a thermostat. I am tired of these so-called experts giving legs to these myths! I will put my professional engineering experiences up with his any day any where.


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STEVE JACK
ConceptOne Pulleys and Brackets

Northern/Southern Rodder Magazine's "Jack'Stands" author and creator
Techical forum/links at www.inccn.net/techforum.htm (http://www.inccn.net/techforum.htm)



[This message has been edited by HOTRODSRJ (edited 07-08-2002).]

i installed an Edelbrock performer intake/cam set 2 years ago,
i also installed a High flow water pump,and a high flow thermostat {180 degree F.}
my engine was /is, making noticably more power,and more heat, i installed a Modine 3 core big block radiator,and a repro fan shroud,and it still wasn't enough for high speed extended hot day drives.
Like driving from Carlisle car show to Albany NY in 85 deg. weather at 70 ish mph,i was running 200-205 consistently,
I then installed a Griffin Large tube
{ two 1.25 inch cores,instead of two 1 inch cores} radiator,i still have Not reinstalled the fan shroud;and the car runs185-195 now, with the same t'stat,fan water pump etc..
Oh,when trying to cool the car down i added a front airdam/spoiler it cost about $30 +
shipping from one of the aftermarket places,it helped about 5 deg. on theroad;
I had also added a 12 inch pusher fan,thermally
activated to help in traffic jams,i Still have Not reinstalled that either...
http://www.camaros.net/forum/smile.gif

Caveman...your empiracle evidence is a good example of several things you did to improve your cooling systems efficiency.

The first addition of the high flow water pump etal, was a great idea, but if you have insufficent ways of dealing with the additional heat that is carried by the water/coolant, the bet is off and it won't help unless the raditor can handle the additional heat.

The next step of putting in larger tubes did two things. It increased the flow due to the large tubes and it also increased the heat transfer properties of the radiator due to more surface area/finnal area. No wonder you are running around cooooool as can be.

One more point....if you are not running on the thermostat at cruise, I would suspect that the mixture is a tad lean regardless of your fan situation which you do NOT need at cruise.....check it out.

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STEVE JACK
ConceptOne Pulleys and Brackets

Northern/Southern Rodder Magazine's "Jack'Stands" author and creator
Techical forum/links at www.inccn.net/techforum.htm (http://www.inccn.net/techforum.htm)

[This message has been edited by HOTRODSRJ (edited 07-08-2002).]

When we first fixed up my Camaro we fixed up the engine to brand new with about 360 hp but put the original radiator which is a 3 core not a 2 (b/c I have AC) and we put the original water pump back on... you have to see that the car sat for 28 years so we should have put a new water pump but anyways... so it's winter out and the high is like 50-55 so it runs real cool, until this summer comes it would run for 15-20 min at 190 and then keep heating up and it wouldn't ever stop so I couldn’t drive until night time, so we got a new 4 core with high-efficiency fins and a high flow water pump, a 185 thermo with an overflow bottle, with 20% anti-freeze 80% water and 2 bottles of water wetter, and a cultch fan and it never gets above 200 ever not even setting at a light or in a traffic jam when it’s 110 out... so it seems to me that the hi- flow water pump had something to do with it and also the over flow bottle which I was told is a must have if your car is over heating it helps so much b/c it always keeps the radiator full of fluid and keeps all the air bubbles out so the water pump runs at 100% efficiency and same with the radiator….

One more point....if you are not running on the thermostat at cruise, I would suspect that the mixture is a tad lean regardless of your fan situation which you do NOT need at cruise.....check it out.
hmm, i keep forgetting to look at the plugs after a high speed long distance run..... Doh,LOL..
i know if i had the $$ that some aluminum heads would be nice!
i use an empty bottle of water wetter for my overflow bottle,i needed something to use quick the day i went to the local drag stip
http://www.camaros.net/forum/smile.gif,and 2 plastic cable ties later !

I got us this morning to find several emails from lurkers and posters here on my dissertation about flow, agreeing with a few here. The general question was why is more flow better. So here I am to offer the reader's digest version of why more flow is better, as shown by Kel's equation.

First we have to inject the fact that as water/coolant approaches it's corrected vapor point (boiling/gassing), it loses disproportionally its ability to absorb heat. In other words, it absorbs a lot of BTUs quickly at a lower temperature and as it approaches it's corrected vapor point it will take longer to absorb the very same amount of heat and so on. What this constitutes is that the longer the water sits in a heat source (the engine) the more diminished returns you get as temperature rises. It's a thermal abyss so to speak.

Now given that the radiator is always designed to be a larger BTU killer (or supposed to be in normal cooling systems) than the engine can normally produce (this is why it cools) and the cooling system design is a closed loop system, the longer the coolant sits in the engine, the more heat it will absorb but the more heat it will leave behind due to the thermodynamic facts of the paragraph above. Now the coolant sits in the radiator longer does get cooler, but the radiator is already shed a disproportionate amount of heat compared to the heat absorbtion in the engine (hopefully) and can be utilized immediately. By getting the already prepared coolant into the block, the additional heat will not build and the coolant will absorb more heat per unit/time. So, if you slow the flow, the heat that gets left behind by slowing the flow builds to levels that eventually overwhelm the engine and hotspots start to form and push coolant out. Only by increasing the flow will you produce the best results and keep the coolant at the peak of efficiency to absorb heat in fast and in abundance.

Class dismissed.

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STEVE JACK
ConceptOne Pulleys and Brackets

Northern/Southern Rodder Magazine's "Jack'Stands" author and creator
Techical forum/links at www.inccn.net/techforum.htm (http://www.inccn.net/techforum.htm)

Steve is right on.

The only thing I would ad, would be you need the air flow through the radiator (fan side) to remove the heat from the coolant side.

One of the most important aspects of this is the prevention of recirculation. Use a fan shroud. This effect will be most noticable at low speeds and idle. Of course, you have to pull enough air across the core and this is directly related to your fan selection where you must consider fan speed, blade pitch, number of blades and so on.

It's not rocket science but it does get interesting.

Kel

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North Texas Camaro Club (http://www.northtxcamaros.com)

Is the glass half empty or half full???.....Neither, the glass is twice as large as it needs to be!