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Water Pump ****

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OK, putting together the 451...ordered any old water pump not knowing any better and received an aluminum housed iron rotary vein pump. I then came across a few threads downplaying this pump style and instead recommending the 6 blade Milodon HV pump. I have them both on the work bench and wanted to show you some interesting comparison photos.

Rotary Vein Pump:
  • gusset reinforcements on outer housing
  • billet mounting flange
  • heavier of the two
  • 1/4" tall billet inner shoulder with smooth flat face behind rotary vein platform
  • 1-1/4" distance from water pump housing face to most distant blade feature
    • Heavy duty thick cast iron rotary vein solid one piece setup


    Milodon HV Pump:
    • no gusset reinforcements on outer housing
    • non-billet mounting flange
    • lighter of the two
    • 3/32" tall inner shoulder with ribbed connical inner face behind 6 blade circular platform
    • 1-1/16" distance from water pump housing face to most distant blade feature
    • visible "wire" wrapped around shaft behind blade platform
    • thin sheet steel (or aluminum?) circular plate with 6 fin blade welded to the circular plate at one location each

From all appearances, if I didn't know any better, I'd say the rotary vein pump overall looks like better quality and could be better overall, but many of you say that the Mildon HV pump actually flows and cools better. Is this still the consensus?

See the side by side photos:
H2OpumpSide.JPGH2OpumpTop.JPGH2OpumpBlades.JPGMilodonBlade.JPGRotaryVeinBlade.JPG
 
I just replaced the water pump on my 383 no a/c, but it has eight blades. Does your have a/c.
 
my car did not come stock with A/C, but I'm installing an aftermarket A/C so I bought a 6-blade that is for an A/C car. Counter-intuitive at first, but the 6 blade pump is supposed to cool better than the 8 blade. It also has to do with the small vs big overall diameter of the entire blade assembly. A smaller diameter will spin faster.
 
The Milodon pump has a built-in 360 degree gusset. Since the pump nose and base flange do not make a 90 degree angle like the rotary VANE pump does, a gusset is not needed for extra strength. The Milodon impeller has worked just fine for years, so it has its merits, as does the vane style also. To make a absolute comparison, you would need to test them in a similar test environment to map their flow/RPM. Looks is not always a proper way to determine a better product.
 
The cast impeller typically flows better than the stamped steel ones. In this case, the steel one has the metal disk added to improve flow. So, they will probably flow about the same but it would be difficult to be certain without proper testing. The one with the least amount of clearance with the back of the pump housing will flow the best (between these two).
 
A smaller diameter will spin faster.

Not so. The diameter of the fan belt pulley determines the speed at which the shaft turns, not the impeller diameter. If your rotary vane pump is from 440 Source, the back of the impeller is VERY close to the inside of the water pump housing and requires a 'thick' gasket to provide clearance (extra cost). Also, if you use their stainless steel water pump bolts and have an aluminum housing make sure you use anti seize if you ever want to remove them. I am curious as to why the Milodon pump impeller assembly is so much shorter. I have the Mancini water pump housing and the Milodon pump on my car and they work fine. I remember checking the impeller to housing clearance and it was about .050-.060".
 
The Milodon pump has a built-in 360 degree gusset. Since the pump nose and base flange do not make a 90 degree angle like the rotary VANE pump does, a gusset is not needed for extra strength. The Milodon impeller has worked just fine for years, so it has its merits, as does the vane style also. To make a absolute comparison, you would need to test them in a similar test environment to map their flow/RPM. Looks is not always a proper way to determine a better product.
X2 on that it's the only way to say which one has the better flow rates.

- - - Updated - - -

Also don't think that just because you have a high flow rate that it will cool better, the heat in the coolant needs time to dissipate through the radiator and it can't get it done if it's flowing to quickly.Imo it's better to have an evenly matched system then it is to have a super fast flow rate.
 
If I were to guess which would move a higher volume of fluid per rotation, I would go with the Milodon. The blades are taller and the diameter is larger.

However...as far as cooling efficiency....I agree with Michael789.....more isn't necessarily better.
 
X2 on that it's the only way to say which one has the better flow rates.

- - - Updated - - -

Also don't think that just because you have a high flow rate that it will cool better, the heat in the coolant needs time to dissipate through the radiator and it can't get it done if it's flowing to quickly.Imo it's better to have an evenly matched system then it is to have a super fast flow rate.

I agree with this, not enough time to dissipate heat in the radiator but also not enough time to pick up heat in the engine.
Too many people have overheating problems and this is just one of the reasons.
Hope it works out for you.
 
The rotary vein pump flows well enough at high rpm, but it's a real dog when your just sitting there idling in traffic on a hot day, which is when you really need it the most. Yes, I have tested a few of these pumps myself, along with another guy over at DC.com that ran tests on just about all of them. The Milodon HV pump came in as a good overall performer.
 
In some applications you restrict flow to help cool better
 
Yeah, but not when your idling in traffic on a hot summers day... :icon_biggrin:
 
this has been discussed to death on DC.com...the rotary pump on the left is junk, don;t use it...stay with the stock pump on the right
 
Thanks to all! I just wanted to see what you would say before I shared the thread I found last week. The Milodon HV came in near the top in performance and the rotary vein last. It's weird though, because visual inspection appears to show the cast iron impeller pump looks like better quality. Here's a thread I found where the guy did a pump shoot-out with lots of cool photos.

I didn't get the rotary vein pump from 440 source. I got it from Mancini or Bouchillon, I can't remember which. My pump housing is the good quality Mancini one.

Check out this thread starting at page 8 half way down where you see the photo with all the pumps together.
http://www.dodgecharger.com/forum/index.php?topic=60599.175
8 + 440 H2O Pumps to test.jpg
 
Ayuh... that's the one alright!

Mike (AKA: Musicman)
 
Last edited:
Hey, I just remembered where I bought the cast iron rotary vein impeller pump from - Bouchillon Performance. Maybe all rotary vein pumps are not the same. They claim this one flows well - not sure if it cools well.

Here it is: Fits B/RB/Hemi Engines. Same Outside Dimensions As Stock Cast Iron Version, Except Housing Is Made Of Aluminum. This Pump Weighs In At Only 4 Pounds. Its Has Large H.D. Bearings and Flows:
New High Flow Impellar Design Flows:
39.6 Gallons/Per Minute At 4,000 RPM
Compare to Mopar Performance
Part # P4529102 or P5007643AC Pumps
Not Bad For a New Contender, Priced Far Less Than Mopar Performance P4529102 or P5007643AB
WP440
B/RB/Hemi Aluminum Water Pump
 
Thanks to all! I just wanted to see what you would say before I shared the thread I found last week. The Milodon HV came in near the top in performance and the rotary vein last. It's weird though, because visual inspection appears to show the cast iron impeller pump looks like better quality. Here's a thread I found where the guy did a pump shoot-out with lots of cool photos.

I didn't get the rotary vein pump from 440 source. I got it from Mancini or Bouchillon, I can't remember which. My pump housing is the good quality Mancini one.

Check out this thread starting at page 8 half way down where you see the photo with all the pumps together.
http://www.dodgecharger.com/forum/index.php?topic=60599.175
View attachment 216975

It is not really weird. The cast blade is curved the steel is straight. The cast blade has more clearance on the pump casing, the steel blades have less. Plus why would you want to add weigh to motor when not necessary for increased performance? G
 
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