[Mr_GTO]

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[Hattmann68]

I love this topic. 35 pages and still going hope it goes over 50 when it is said and done. Also George K. gotta be getting rich by now. Chalk up one more post.

[69firebird455]

Any fluid engineers out there???

Anyone know why the vanes on these water pumps are agressivly reverse swept? If you look at the pump from the impeller end the shaft turns to the left (c/clockwise). Most pumps use a neutral or forward swept vane. Seems like the reverse swept vanes would seriously slow the flow down.

Actually, if you think about it, this pump acts more like a screw then a centrifical pump. IMO

So what's the reason behind this????

[Bad Karma]

What happened the thread is no longer featured?
Can we get it Featured again. I feel this is a very useful and informative thread

[dave bolduc]

so what you are saying is that there wont be any more HOT running pontiacs????????

ya.ok..............bridge for sale!

[george kujanski]

And there will be world peace, unlimited petroleum, no pollution, and best of all, NO PARIS HILTON!!!!!!!

George

[cwolf]

somebody restickey this please

[Phil Goat Nelson]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by 69Firebird455:
Any fluid engineers out there???

Anyone know why the vanes on these water pumps are agressivly reverse swept? If you look at the pump from the impeller end the shaft turns to the left (c/clockwise). Most pumps use a neutral or forward swept vane. Seems like the reverse swept vanes would seriously slow the flow down.

Actually, if you think about it, this pump acts more like a screw then a centrifical pump. IMO

So what's the reason behind this???? </div></BLOCKQUOTE>

I'm no "fluid engineer"....or any other kind for that matter, but maybe this one works by pushing fluid through, rather than pulling it through?

[60man]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Phil Goat Nelson:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by 69Firebird455:
Any fluid engineers out there???

Anyone know why the vanes on these water pumps are agressivly reverse swept? If you look at the pump from the impeller end the shaft turns to the left (c/clockwise). Most pumps use a neutral or forward swept vane. Seems like the reverse swept vanes would seriously slow the flow down.

Actually, if you think about it, this pump acts more like a screw then a centrifical pump. IMO

So what's the reason behind this???? </div></BLOCKQUOTE>

I'm no "fluid engineer"....or any other kind for that matter, but maybe this one works by pushing fluid through, rather than pulling it through? </div></BLOCKQUOTE>

Actually I thought it did the opposite..That is it pulled the water into the "eye" of the impeller and dispersed it from the outer edge under pressure much like a centrifical pump on a fire truck.. The "plate" is used to make sure the water enters where it should..that is why the clearance gap is critical....I might mention that a centrifical pump takes advantage of any incoming pressure and multiplies it. That is what we were taught in Fire Training.....
JMO.

[george kujanski]

What I see, and agree with 60man:

The pump works by forcing fluid out towards the outer edge (discharge). In doing so, the outlet pressure must be increased also. In turn, a lower pressure area is created in the "eye" of the pump which is a suction to draw fluid from the engine block and the radiator lower hose when the t-stat is open. Since there is a suction on the intake side, which is lower than atmosperic pressure, there is a tendency for the lower rad hose to collapse unless there is a spring inside it to keep it open.

From the vane design, I wouldn't call the vanes "reverse swept". The design is intended to move the fluid out from the eye towards the outside diameter of the wheel. How else would that be done?

George

[Half-Inch Stud]

George, yea. Impeller shown is correct for throwing fluid.

You all now notice how the Dual outputs are NON-SAME. As if the designer put a preference to water flow into the ___er-side of the engine. My question is: By looking at the pump outlet designs, which engine bank was designated for more flow?

Have a nice day. HIS

[69firebird455]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Half-Inch Stud:
George, yea. Impeller shown is correct for throwing fluid.

You all now notice how the Dual outputs are NON-SAME. As if the designer put a preference to water flow into the ___er-side of the engine. My question is: By looking at the pump outlet designs, which engine bank was designated for more flow?

Have a nice day. HIS </div></BLOCKQUOTE>

Nice observation HIS. I can tell you the side that flows more just happens to be the side the heater core draws from. Maybe this is intended, maybe not. There is maybe half the flow coming from the other side of the pump compared to the heater core side! One has to wonder if this reduced flow could cause overheating/detonation on the left engine bank??

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by george kujanski:

From the vane design, I wouldn't call the vanes "reverse swept". The design is intended to move the fluid out from the eye towards the outside diameter of the wheel. How else would that be done?

George </div></BLOCKQUOTE>

George, Great explanation of how the pump moves water. As far as my statement about the reverse swept vanes, I called the vanes "reverse swept" because on most blowers and water pumps the vanes are straight or they are pitched a bit forward. Like the blower wheel out of your heater core. Look at the vanes and think about the direction the wheel turns. The vanes are "forward swept". This tends to increase velocity as the fluid/air leaves the impeller/vane. On this pump the vanes are "reverse swept" and i would guess that reduces the velocity of the water as it leaves the impeller? Just wondering why they did it that way.

[george kujanski]

69: If I remeber correctly, the "squirrel cage" blower wheels used in heaters have the same pitch direction relative to the direction of rotation that the water pump does.

I guess I don't know what you mean by reverse swept.

george

[69firebird455]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by george kujanski:
69: If I remeber correctly, the "squirrel cage" blower wheels used in heaters have the same pitch direction relative to the direction of rotation that the water pump does.

I guess I don't know what you mean by reverse swept.

george </div></BLOCKQUOTE>

George, look at the picture of the pump Mr_GTO posted. Look at the vanes, the impeller turns Counter Clockwise. That means the vanes are Backward Incline instead of Forward Curve. Take a look at the drawing but keep in mind the rotation in the drawing i'm posting is opposite the pontiac pump.

[george kujanski]

Well, I'd say it's a forward curve, relative to the actual direction of rotation of the pump. your dwg shows the forward curve rotating in the opposite direction of the actual pump.

I think the important thing is the blade design must be stated in terms of the normal direction of rotation. Based on your dwg, and drawn rotation, I would call the left dwg a backward, the center a forward.

If you take a Pontiac pump and turn it backwards, it would most certainly suction from the outside and pressurize the center. May not be too efficient, tho.

George

[R/ABANDIT]

I am so glad that I found this post tonight. Because my car has been running at 220 had to put the heat on just to get it home tonight. I'll be tearing her apart tomarrow now that I know what it is. I have a BeCOOL 4 core & a 160 stat & didn't know what to do next. Thanks George.

[GoatGlider]

my humble contribution:

the design of the impellers blades has to do with how quick you want to have the fluid flowing. like the gradient of a screws thread.

speeding up the flow of coolant may help with your heat-problem or not, but coolant needs some time in the radiator to cool down. not too long and not too short.

the cooling system is designed to let the cooland run with a certain speed. not only the pump is relevant, but e.g. the holes from cylinder bank up to the heads or the bypass-hole under the thermostat that is always open.

if you get a bigger radiator, it would make sense to speed up the flow with a more efficient pump. if your cooling system is swamped with dirt, it may help to enforce input pressure. if the pump is out of specs, it should be restored.

however, it needs to find the most optimal flow-speed AFTER you flushed the system clean, have a suitable thermostat and a big enough radiator.

and: my 65 gtos water pump has a divider plate to make sure both cylinder banks get a similar amount of coolant delivered. don't forget that the heater radiator does cool down coolant and therefore compensates the "stolen" amount of fluid for the right bank before giving it back in the right cylinder head.

[buwalda]

69FB455,
I believe the flow [ and temp ] to both banks is close to equal. I have a friend who has a temp gauge at the front of each head & both gauges read within 2-3 degrees [ F ] of each other. I also believe each bank gets equal pressure. If you look at the pic a few posts back, the pump area outside of the impeller is all open 'territory'; the water can go anywhere it likes, because there are no walls or partitions to divide it, so output pressure would be the same throughout the pump housing after exiting the impeller blades. To create pressure, you have to have a restriction somewhere in the system, which is the thermostat. If you add up the area of all the deck holes for both decks & compare it to the t'stat opening area [ which all the water except for bypass must pass through ] , you will find the t'stat is the restriction in the stock configuration.

[GoatGlider]

that's an important point: the thermostat opening is quite small indeed and IS the restrictive point.

one wonders why they attach such a fat rubber pipe behind, going to the radiator, if the thermostat does not allow to flow more

removing the thermostat is one of the things i would try to help with a permanent overheating issue. if your engine reaches working temperature anyway, i can't see any reason, not to try this. this increases flow dramatically it will give you a hint, if radiator size or coolant flowing speed is your problem.

and, btw, when flushing the system it helps a lot to remove the thermostat at least temporarily.

btw II: it seems that earlier water pump models like the one in my 65 gto had the divider plate, while later ones had it not. this plate divides the pump area into 2 vertical slices, where the inner one feeds the right bank incl. heater and the outer one feeds the left.

[LeighP]

Removing the thermostat isn't the answer...my t/A had its t'stat removed by a previous owner trying to fix an overheating problem....all that accomplished was to not let the car warm up properly, or on a freeway run it would stay cold, then in traffic it would get very hot.
I fixed the problem by replacing the t'stat with a 160 deg one and replaced the non-operative fan clutch...which was the cause of his problems to begin with.
On a side note - after reading this post I was concerned that the new pump I'd ordered with some other parts would be a cast impellor type or not (I'm currently building a 455)....glad to say when the pump showed up it was a cast impellor....brand - "Federal Mogal Carter Pumps" on the box.
And even better, testing the clearance between the new plate and the vanes showed it to be quite close straight out of the box. I've yet to actually measure it though.