I took apart three 383 motors this week and three different water pump impellers. Which is the best cooling and where do you get a new one?

far left, 10 blades. I would add an anticav plate, you gotta cut it in half & weld it in behind the vanes

I would use either a milodon high volume pump. looks like the on on the right but already has an anti cavitation plate. or use a flow kooler. twice as many vanes as the one on the left.

Factory AC cars used fewer blades because the smaller pulley on them rotated the pump much faster.
Today there is no AC or NON ac choices.

I don't believe the pump with the cast impellers is available anywhere.

Here is a reference picture for the above mentioned FlowKooler. FK uses the same aluminum casting as a stock unit but they have their own spindle design that they mount to the casting.

(These are SB reference pictures)

There was a somewhat instrumented test done in the past with a whole gaggle of pumps. The result?

Throw 'em all in a pile and pick one.

On the street it really didn't make an appreciable difference. Sure, some performed better than others at a specific rpm but they fell behind at another rpm.

Use the one with the best feel to the bearings.

The cast impeller already has the "cavitation plate" as part of the impeller. No need to cut and try to weld the cast iron.

I like the Milodon pump just on principle, no logical reason.

R.

I used a flow kooler in my 71 cuda with A/C. The temps were all over the place. Cool at times, hot at times, very unpredictable. I finally found an A/C water pump, and the temps didn't vary any more. It was a constant 185 with a 180 thermostat. It does make a difference what pump you use.

i've tried every style of mech pump i could get my hands on and haven't found any noticeable difference.

My experiences over the years concur with the above statement.

Mopar OEM used 'A/C' pumps in A/C applications for a reason...

They worked...


Been running an A/C pump for many years...

Along with an OEM rad, Viscous drive, A/C fan, and shroud...

In brutal conditions...


Zero temp issues...

According to the 70 FSM, each pulley ratio used different vanes. I dont think this was by accident.

Over engineered? who knows. Now I know why its so hard to build a pulley set from a pile of parts. lol

Maybe I shouldn't have posted on this thread...

tonight my 68 Charger started pouring AF out the water pump on the way home from the local cruise night...

I put the current pump on in ....1992.. hope it's replacement will last that long....

It is an AC car with the small wp pulley.

Flowkooler

The pump with the most vanes and largest diameter vane-blade will pump the most water.
But that same pump could very cavitate if spun too fast.

Ma Mopar knew how to do its homework and choose the correct number/diameter vane-wheel with the correct belt-pulley.

Agreed & the anticav plate is the best of both worlds. either Ma did not know about it at the time or if she did then it was more cost efficient to adj pulley ratios/vane count to deal with avoiding cavitation

I ordered a Summit Racing pump, comes with 8 fins, anti cav plate and made in USA. Cast iron housing.

I will report results after install.

$46.00 plus shipping.

8 fins/plate/$46/USA cant beat that!

Brutal conditions?

In Detroit?

Socio-economic issues should not affect cooling unless the radiator gets punctured.



I've run all kinds of pumps in Texas summers over the last 30 years and never had a problem related to a properly working water pump.

I will agree that the rest of the cooling package (radiator, fan clutch, fan, shroud, hoses) play a critical role. I would go so far as to suggest that the type of factory water pump used is not a major concern.

The A/C water pumps were changed due to the pulley sizes in use. In the end, the pump did not play a major role.


Scroll about half way down this page:
http://www.dodgecharger.com/forum/index.php?topic=60599.175

He tested 12 pumps of various origin on a 440 powered motor home with a flow meter attached. Then he posted results based on rpm and gpm.

Where he found a difference was in the water pump housings at low speed.

Impeller Diam 4.375", 8 blades, stamped sheet metal, tested with housing on left and right.
RPM . . GPM hole . GPM no hole
1000 . 18.0 . . . . 14.5
1500 . 23.5 . . . . 18.5
2000 . 33.0 . . . . 23.0
2500 . 28.0 . . . . 29.0
3000 . 28.0 . . . . 28.0
3500 . 28.0 . . . . 27.5

I've done a bit of water pump comparing a while back on my '65 300.
Its engine (400ci) ran hot after a highway run and wouldn't come down entering the city again.

Short of fabbing a custom fan-shroud, I did some thermostat, waterpump and housing swaps.

I had found no real difference in cooling between a 440Source housing and stock castiron housing, but I did find a considerable flow difference in the 440source waterpump and a stock waterpump.

With the 440source waterpump, the water in the radiator would just 'flow by' like a quiet mountain stream, even when the engine was revved.
With the stock waterpump, the coolant would flow by noticably, and would really rush by when the engine was revved.