Parts stores not stocking the 6 vane waters pumps for the a/c cars.

[68 Sport Satellite]

I've been running the eight blade since the beginning in my 440 non a/c. Never had any overheating issues, even on a hot day in stop and go traffic.
View attachment 1327211

That's awesome.
I think the thinking is that with the non-A/C car, it's 8-blade pump with larger pulley and with an A/C car, stock OEM was a 6-blade pump with the smaller faster moving pulley. The 6-blades was to minimize cavitation at higher RPM's due to the smaller faster moving pulley.

 

[GMP440]

That's awesome.
I think the thinking is that with the non-A/C car, it's 8-blade pump with larger pulley and with an A/C car, stock OEM was a 6-blade pump with the smaller faster moving pulley. The 6-blades was to minimize cavitation at higher RPM's due to the smaller faster moving pulley.

Did some road testing today. Drove in stop and go traffic and longer stretches with no traffic lights. Cooling with the 8 vane pump is just as good or better than the 6 vane pump. No temperature fluctuations or overheating whatsoever. Everything went well.

 

[68 Sport Satellite]

Did some road testing today. Drove in stop and go traffic and longer stretches with no traffic lights. Cooling with the 8 vane pump is just as good or better than the 6 vane pump. No temperature fluctuations or overheating whatsoever. Everything went well.

what's the highest speed you got up to? If over 60mph and all was well, you should be golden.

 

[GMP440]

Looking to replace the water pump that's in my 68 Coronet with 318 and a/c. Autozone, Napa, Advance, Orelley's have the 8 vane pumps for the non a/c cars and not the 6 vane pumps for the a/c cars.
Is this an issue where the pump manufacturers are just manufacturing one pump style to be used for a/c and non a/c cars? Will there be any cooling issues using an 8 vane pump on an a/c car?
Who has the correct 6 vane pumps?

Wanted to give another progress report today. Did some high speed runs today. The 8 vane pump cools the same as the 6 vane pump I removed. No cooling issues at all. End result; both 6 vane and 8 vane pumps cool the same.

 

[68 Sport Satellite]

Wanted to give another progress report today. Did some high speed runs today. The 8 vane pump cools the same as the 6 vane pump I removed. No cooling issues at all. End result; both 6 vane and 8 vane pumps cool the same.

Thanks so much for the real world feedback. Very cool

 

[albert 5694]

Double check with you local NAPA guy i was looking for a 6 vane pump for my 440 w/ac and he had to do some looking in is books old school way and found one that is a 6 vane NAPA one. I don't think you want to use the 8 vane pump unless you change both the crank pulley and the pump pulley as the pump speed will be to fast and not move more water it will actually cause cavitation with the 8 vane pump causing a lot of air in the block witch will not let it cool very good. You can not just change the pump pulley because the non ac pulley will hit the crank pulley as the ac crank pulley is bigger and the ac crank pulley and non ac pump pulley are to big to use together.

 

[GMP440]

Double check with you local NAPA guy i was looking for a 6 vane pump for my 440 w/ac and he had to do some looking in is books old school way and found one that is a 6 vane NAPA one. I don't think you want to use the 8 vane pump unless you change both the crank pulley and the pump pulley as the pump speed will be to fast and not move more water it will actually cause cavitation with the 8 vane pump causing a lot of air in the block witch will not let it cool very good. You can not just change the pump pulley because the non ac pulley will hit the crank pulley as the ac crank pulley is bigger and the ac crank pulley and non ac pump pulley are to big to use together.

Thanks for the input. When was it that Napa found the correct 6 vane pump for your 440? This pump has been on for about 2 weeks. It's working very well. For now it's staying on. If in the future I have issues with this one I'll search for a 6 vane. Will check Napa as you mentioned. I still have the 6 vane one I took off. Will hold onto that one. In case sometime down the road I still can't find a 6 vane pump, I'll just send this the one I took off to get refurbished.

 

[diesel_lv]

Very doubt

Double check with you local NAPA guy i was looking for a 6 vane pump for my 440 w/ac and he had to do some looking in is books old school way and found one that is a 6 vane NAPA one. I don't think you want to use the 8 vane pump unless you change both the crank pulley and the pump pulley as the pump speed will be to fast and not move more water it will actually cause cavitation with the 8 vane pump causing a lot of air in the block witch will not let it cool very good. You can not just change the pump pulley because the non ac pulley will hit the crank pulley as the ac crank pulley is bigger and the ac crank pulley and non ac pump pulley are to big to use together.

Very doubtful that an 8 vein pump will have any issues. Flowkooler pumps have 16 veins. Been running 1 for over 2 yrs. No problems.

 

[hunt2elk]

Very doubt

Very doubtful that an 8 vein pump will have any issues. Flowkooler pumps have 16 veins. Been running 1 for over 2 yrs. No problems.

Exactly what I was just thinking. I have Flowkoolers on all 3 of my cars with the factory pulleys.

 

[albert 5694]

Just remember you are not comparing apples to apples the flowkooler works totally different then the oem 8 vain it is designed to run faster the original was not designed to run that fast it is not always the vain count it is also the design of the veins.

 

[RJRENTON]

Just remember you are not comparing apples to apples the flowkooler works totally different then the oem 8 vain it is designed to run faster the original was not designed to run that fast it is not always the vain count it is also the design of the veins.

The METHODOLOGY of how the coolant is circulated, in terms of Gallons/Minute and the Pressure at which it is circulated and the RPM the pump is running at (average) is the determining factor.......not the the number VANES the pump has. Internal pump clearances also determine how well the pump operates. Not sure WHY everyone has fixated on the pump VANE (or impeller blade) count......the RESULTS are (or should be) the determining factor..... Just my opinion of course...
BOB RENTON

 

[68 Sport Satellite]

The METHODOLOGY of how the coolant is circulated, in terms of Gallons/Minute and the Pressure at which it is circulated and the RPM the pump is running at (average) is the determining factor.......not the the number VANES the pump has. Internal pump clearances also determine how well the pump operates. Not sure WHY everyone has fixated on the pump VANE (or impeller blade) count......the RESULTS are (or should be) the determining factor..... Just my opinion of course...
BOB RENTON

I agree, but I think people get stuck on this because of the original OEM designs only having the 2 options - 6 (A/C car with small pulley) and 8 (non-A/C larger pulley). So that thinking has just carried over, but you are right in my opinion. Now they have anti-cavitation plates, different blade geometry, etc.

 

[RJRENTON]

I agree, but I think people get stuck on this because of the original OEM designs only having the 2 options - 6 (A/C car with small pulley) and 8 (non-A/C larger pulley). So that thinking has just carried over, but you are right in my opinion. Now they have anti-cavitation plates, different blade geometry, etc.

I guess the majority of contributors are believers in the principle that: 6 is better than 8 or maybe its 8 is better than 6.....which may apply to pump vanes (impeller component) or to other factors of life in general, or perhaps, as several of the contributors to this thread noted, it doesn't really matter.....or....maybe it does matter, but maybe its related to the color of the coolant or its concentration....or.....maybe its the fundamentals of fluid dynamics......only the "shadow knows for sure"...... just talking out loud with tongue in cheek........
BOB RENTON