Water pump

[ggdad1951]

Hank

Here are pictures of my old pump the original pump had the two blade impeller

and here is a picture of an impeller like on the new improved pump

I would think the new impeller design would pump more water.

Harvey

it will, in fact, I'm thinking I'm going to swap mine out! Was that just a new impeller from NAPA (or someplace else) or a whole new pump?

[Dave72dt]

The new style impeller has a clearance spec between the pump vanes and the pump body. Too much clearance and it won't pump any better than the old one

[HanksB3B]

The two blade pump is not OEM but was a rebuilt water pump that either you or the previous owner installed. The 6 -blade impeller is OEM. I highly doubt that some leprechan messed with your temperature guage, nothing changed there. But maybe going from a 2-blade impeller to a 6-blade impeller made a 20deg change in operating temperature. This would mean the two blade impeller is more efficient.

Hank

[TodFitch]

The two blade pump is not OEM but was a rebuilt water pump that either you or the previous owner installed. The 6 -blade impeller is OEM. I highly doubt that some leprechan messed with your temperature guage, nothing changed there. But maybe going from a 2-blade impeller to a 6-blade impeller made a 20deg change in operating temperature. This would mean the two blade impeller is more efficient.

Hank

Every 1933 water pump I've seen and every MoPar boxed water pump repair kit I've seen has the two bladed version of the impeller. And I've never seen a L-6 engine water pump impeller that looks like that 6 bladed one. So I am a bit confused about your statement as to which was OEM.

[Young Ed]

Me too the old ones I've taken apart are 2blade ones. The brand new one I bought from Napa is the turbine blade version. I noticed no difference in my plymouth but I haven't driven it much since the repair.

[HanksB3B]

The weird thing is I've had around four or five water pumps and they have all had the 6-blade impeller except for one which I had assumed to be a rebuild.

here's an Ebay Photo of what is described as follows:

NOS 48-49-50-51-52-53-54-55-56 plymouth dodge desoto chrysler water pump repaır kit bushing type 1325977

Hank

[ggdad1951]

from one of my previous lives where we built fluid pumps, I'd have to say the turbine style impeller should be much more effcient at moving fluids as more blades are in contact with the fluid during rotation. I'd expect a better flow with the turbine version vs. two flange version. Now of coarse there is always how much less volume is availalbe to move with the more complex turbine taking up the volume space being moved...and I was told there would be no math here....don't make me do calc again!

[HanksB3B]

That's gotta be it!

Do the math:

E-Mc sq x6=180 or E=Mc sq x 2=212

Hank

P.S. Harvey did you mention if your Napa "Improved Flow" pump is 2 or 6 blade? (I may have to throw out my whole theory)

Edited September 1, 2010 by HanksB3B

[H Suhling]

ggdad1951

That is the impeller that came in a rebuilt kit from Robert's.

Hank

The new pump from NAPA has the turbine type impeller

Harvey

[HanksB3B]

So much for my theory...So let me get this straight:

The rebuild kit from Roberts has 2 blades. I suspect this is typical for most of todays rebuilds and think this is a generic part used because it fits a wider range of similar applications.

Provided that you removed the backing plate the new one from Napa has the oem 6-blade impeller. Correct? (notice how I snuck "oem" in there) The impellers shown in the Cooling System of the Dodge Truck Shop Manual pages 181-183 all show the 6-blade impeller.

Hank

[ggdad1951]

That's gotta be it!

Do the math:

E-Mc sq x6=180 or E=Mc sq x 2=212

Hank

P.S. Harvey did you mention if your Napa "Improved Flow" pump is 2 or 6 blade? (I may have to throw out my whole theory)

NOOOOOOOOOOOOOOOO, no more math! My brain will explode! 2 years of calc was enough! I'm already educated beyond me intelligence!

[TodFitch]

... The impellers shown in the Cooling System of the Dodge Truck Shop Manual pages 181-183 all show the 6-blade impeller.

And the illustration for part type code 7-45-1 "Water Pump Shaft Package" in the 1936-48 Plymouth parts book shows the two bladed impeller. And the illustration on page 70 of the 1948-54 Factory Plymouth Service Manual shows the two bladed impeller too.

Maybe the difference we've been going back and forth on is a truck versus car thing...

[HanksB3B]

And the illustration for part type code 7-45-1 "Water Pump Shaft Package" in the 1936-48 Plymouth parts book shows the two bladed impeller. And the illustration on page 70 of the 1948-54 Factory Plymouth Service Manual shows the two bladed impeller too.

Maybe the difference we've been going back and forth on is a truck versus car thing...

I also find ggdad1951's comments interesting as well. But back to H Suhling's original problem of the operating temperature of the engine I'm at a loss. The oly thing left is the fan belt is slipping. I give up.

Hank

[Reg Evans]

And the illustration for part type code 7-45-1 "Water Pump Shaft Package" in the 1936-48 Plymouth parts book shows the two bladed impeller. And the illustration on page 70 of the 1948-54 Factory Plymouth Service Manual shows the two bladed impeller too.

Maybe the difference we've been going back and forth on is a truck versus car thing...

Ah...my sediments exactly.

[olddodgeguy]

Could it be that the new impeller is moving the fluid too fast? Back in the day when I was racing stock cars we had to use a restricter in the system when we removed the thermostat. If we didn't, the water moved too fast and didn't give the radiator time to remove the heat. I know the thermostat is still there. Was just wondering if the principal was the same. Mike

[ggdad1951]

you might be hitting on something there...never thought about the heat transfer in the radiator...if the fluid is moving too fast the radiator might not be able to dissipate the heat fast enough....hmmmmm....NO way do I want to go thru those math gyrations! I'd have to dust off my heat transfer book and find my calc books again!

I guess I'll trust the original parts and move on!

[ggdad1951]

well my "new" water pump came from NAPA yesterday...I think I'm going to use it even tho it isn't "original", right now I just don't wanna deal with a rebuild of the water pump....I'll leave that to when I'm truely bored with nothing else to do on the truck. Has anyone had any issues with the "new" ones from NAPA?

Also my "new" one doesn't come with a grease zerk installed...there is a hole, but I wonder if that isn't a weep hole?

[Young Ed]

I've got a couple 1000 miles on the napa one I put on my plymouth this summer. No fitting on mine either. I believe the hole you are talking about is indeed a weep hole.

[ggdad1951]

I've got a couple 1000 miles on the napa one I put on my plymouth this summer. No fitting on mine either. I believe the hole you are talking about is indeed a weep hole.

so you think the new one is "greaseless"?

[Young Ed]

so you think the new one is "greaseless"?

Correct. I've blown through a rebuilt one on each of my vehicles. So I'm glad to try a new one now. If the rebuilt one on the pickup goes again I'll be putting a new one on there too.

[rustyzman]

Modern replacements will be a sealed bearing with a weep hole. No more grease.

Possible that an over rich mixture of coolant can affect temperature. Also possible that a replacement thermostat is junk and inaccurate. Very possible that you had an air pocket in the block that needed a good burp. I can not believe that a two blade impeller could be more efficient than a turbine unit. If it was, every manufacturer today would be using it, and none of them do.

It may require more torque to turn and that could lead you to a bit of belt slip creating the issue as well.

Try the new one and see what happens.

[Jerry Roberts]

OK guys here is information from a 1976 Motor Engines and Electrical Systems book . This is not mopar specific information . " The older type low speed engine water pump had an impeller with straight radial blades which had ample pumping capacity for idling and very low speed as well as for higher speeds . To make a high volume pump for the modern high speed engine the impeller blades are curved . Such an impeller can be designed for maximum efficiency at any desired pump speed and at this speed is much more efficient than the straight blade pump . However , since its efficiency falls off rapidly when the pump is run at lower ( or higher ) speeds , modern pumps have greater cross sectional area both in the intake and outlet , and thereby compensate for the curved shape of the impeller . "

[ggdad1951]

I was told there would be no math......

[Frank Elder]

I was told there would be no math......

Two kinds of math this complicated stuff and 10, 20, 100....how much is that part? Let me see here I lost count 10, 20,:eek: