[Nitebird]

If a Pontiac 455 water pump is installed correctly meaning the divider or spacer is used and has the correct clearance will it really matter if you are using a water pump with the stamped steel impeller or the cast impeller?

I was just going to buy a water pump at a local parts store which has the stamped steel impeller on it.

[72LuxuryLeMansLa.]

http://forums.maxperformanceinc.com/...d.php?t=411256

[craigs69]

Mine is stamped and works fine with the proper divider plate clearance. I never see anything over 185 degrees.

[77 TRASHCAN]

Originally Posted by craigs69

Mine is stamped and works fine with the proper divider plate clearance. I never see anything over 185 degrees.

X2 here, also!!!

[Mr. P-Body]

Yes, if it's a quality unit (more than $50,), it will be fine. Worry more about the housing and the seal.

Jim

[i82much]

Originally Posted by Mr. P-Body

Yes, if it's a quality unit (more than $50,), it will be fine. Worry more about the housing and the seal.

Jim

I can vouch for Jim on this deal, he built my 505 and it stays about 190 no matter what. I found getting the vacuum advance working really helped with keeping it cool.

[77 TRASHCAN]

My stamped impeller water pump was a new iron housing AC Delco pump, sold through a parts store, been about 7-8 years ago, still cools fine...

[rohrt]

Originally Posted by 77 TRASHCAN

X2 here, also!!!

X3

I have a stamped steel one on my 455. Clearenced on the divider. It has always ran cool around 180 unless its a 100deg out it might creep up in slow traffic a bit.

Went to every store around at the time and could not find a cast impeller.

[Tom Vaught]

Ford runs stamped impeller water pumps on all of their V-8 and V-10 Gas engines and on a lot of the smaller stuff too.

Their pumps are designed for a proper air gap between the stamped impeller and the housing section (in the block on most Fords).

They cool great. Only improvement we ever made to one of the V-10 systems was to use a commercial radiator fan vs a passenger vehicle fan system.

So the point is, if the stamped impeller is properly designed and fitted to the housing it should cool fine (if the water pump pulley ratio is correct) Most fords run smaller Pulley diameters. You might have to do the same on your Pontiac vehicle.

Tom V.

[Squidward]

This is heresy!!!

I was looking for an early short 69 water pump with cast impeller this week. Pickings are slim unless I wanted to drop some gnarley coin. But I have easy access to stamped impeller units. Didn't know if I should get one.

I've always wondered this myself. I live in a place that exploits every cooling system weakness.

[72LuxuryLeMansLa.]

Originally Posted by Tom Vaught

Ford runs stamped impeller water pumps on all of their V-8 and V-10 Gas engines and on a lot of the smaller stuff too.

Their pumps are designed for a proper air gap between the stamped impeller and the housing section (in the block on most Fords).

They cool great. Only improvement we ever made to one of the V-10 systems was to use a commercial radiator fan vs a passenger vehicle fan system.

So the point is, if the stamped impeller is properly designed and fitted to the housing it should cool fine (if the water pump pulley ratio is correct) Most fords run smaller Pulley diameters. You might have to do the same on your Pontiac vehicle.

Tom V.

Tom,

You're the engineer; explain this to me. If a stamped impeller is squared off and a cast impeller follows the contour of the plate; wouldn't the cast impeller be more efficient?

Thanks!

[68azbird]

Who got the shortys?

Originally Posted by Squidward

This is heresy!!!

I was looking for an early short 69 water pump with cast impeller this week. Pickings are slim unless I wanted to drop some gnarley coin. But I have easy access to stamped impeller units. Didn't know if I should get one.

I've always wondered this myself. I live in a place that exploits every cooling system weakness.

[FrankieT/A]

I'm using stamped on 455 with a/c south Florida heat, runs cool as a cucumber 95* days A/C on.

[Tom Vaught]

Originally Posted by 72LuxuryLeMansLa.

Tom,

You're the engineer; explain this to me. If a stamped impeller is squared off and a cast impeller follows the contour of the plate; wouldn't the cast impeller be more efficient?

Thanks!

Like I said in my post the impeller has to follow the contour of the female housing properly.
(In the case of the pontiac that would be the stamped metal plate) Ford impellers have very close tolerances between the stamped vanes and the cast contoured wall. Kind of like the factory stamped metal plate. The stamped impellers better follow the contour of the steel plate with-in .030"-.040" otherwise too much leakage past the vanes.

Tom v.

[72LuxuryLeMansLa.]

Originally Posted by Tom Vaught

Like I said in my post the impeller has to follow the contour of the female housing properly.
(In the case of the pontiac that would be the stamped metal plate) Ford impellers have very close tolerances between the stamped vanes and the cast contoured wall. Kind of like the factory stamped metal plate. The stamped impellers better follow the contour of the steel plate with-in .030"-.040" otherwise too much leakage past the vanes.

Tom v.

So, If I have a stamped impeller and it is not contoured, it would be crap, and another stamped impeller contoured, it would be good to go? I just want to make sure we are on the same page, too much Knob Creek tonight.

[Squidward]

Originally Posted by 68azbird

Who got the shortys?

Called NAPA in Mesa. Said they could get them in a day (local to us). But he said the picture showed stamped impeller.

I carefully tweaked my plate, and put it back in. I didn't see anything wrong with the pump.

[Tom Vaught]

Originally Posted by 72LuxuryLeMansLa.

So, If I have a stamped impeller and it is not contoured, it would be crap, and another stamped impeller contoured, it would be good to go? I just want to make sure we are on the same page, too much Knob Creek tonight.

Lets just say that it would probably be a bit LESS EFFICIENT vs the contoured piece If the contoured piece fit the stamped plate properly. (;>)

Tom V.

[68azbird]

Is there an optimal impeller design, shape, size for pumping requirements that could solve these problems with pontiac engines?

[grivera]

Originally Posted by 68azbird

Who got the shortys?

Our host: Part # GME39A (cast impeller) $49.

[lust4speed]

My stamped steel impeller water pump runs as cool as the previous cast impeller pump. Both kept the engine temperature at thermostat while stuck in traffic with the A/C running on hot days - and you can't ask anything more than that.

The original water pump out of my '67 was a stamped steel impeller right from Pontiac. I'd say that would mean that Pontiac was happy with the stamped impeller's performance.