Water Pump with cast metal blades - dealer??

[blackS2]

I ve got a problem to get a Water Pump with cast metal blades...

Audi dealer deliveres the plastic blade version...

so where can I get the metal type??

thx

[A80Avant]

i couldnt find one either. Only the plastic ones...

[Thuppu]

You have to buy some italian second hand quality.

[sailaz]

I was looking at water pumps and came across the question: which shape of blades would be the best, most efficient ?

[RichLV]

When I was rebuilding mine, I bought a HEPU water pump, it came with metal impeller.

Checking the shop I bought it from, it still says that blades are metal in the description.

Part number - P535. For 3B - P534.

[blackS2]

When I was rebuilding mine, I bought a HEPU water pump, it came with metal impeller.

Checking the shop I bought it from, it still says that blades are metal in the description.

Part number - P535. For 3B - P534.

PK Motorsport sells GK Waterpump with metal blades

[sailaz]

When I was rebuilding mine, I bought a HEPU water pump, it came with metal impeller.

Yes, Hepu has metal blades (it is right bottom in my photo), RS2 OEM has plastic blades (on the left side in my photo)
but
question was about blades shape ......

[RichLV]

Yes, Hepu has metal blades (it is right bottom in my photo), RS2 OEM has plastic blades (on the left side in my photo)
but
question was about blades shape ......

My post was a reply to the OP's question. For yours, probably need to research about propeller design efficiency for liquids. Quick glimpse in google yields some information sources for that.

[sailaz]

probably need to research about propeller design efficiency for liquids.

good advice
but I was wondering what reason was to change blade design ....
two top ones are from old I5 diesel (AEL and Volvo D5252T, and blades shape is a bit different), left one from RS2, blue colour is from first I5 diesel AAT but this one is newer aftermarket for that engine, and bottom right HEPU for old I5 petrol.
I don't know if blades design has been changed on OEM water pumps for old I5 diesels but as we see new aftermakert pumps and diesel and petrol are different from old OEM.

[RichLV]

good advice
but I was wondering what reason was to change blade design ....
two top ones are from old I5 diesel (AEL and Volvo D5252T, and blades shape is a bit different), left one from RS2, blue colour is from first I5 diesel AAT but this one is newer aftermarket for that engine, and bottom right HEPU for old I5 petrol.
I don't know if blades design has been changed on OEM water pumps for old I5 diesels but as we see new aftermakert pumps and diesel and petrol are different from old OEM.

Looking at the the picture, just trying to figure it out logically, the ones with more blade count will create more pressure/movement in the liquid per revolution than the ones with a smaller count. Hence there will be more flow & better cooling. But, I'm no propeller design engineer, so this is just a speculation.

Also, with bigger blades, the resistance of the liquid on a single blade will be stronger, than on the smaller one. But then again it might not be the case for the entire impeller. Bah, go ask an engineer.

[John.]

I've just bought a Febi Bilstein pump........it has plastic impellor, I had ordered a Graff pump () as this has metal impellor I believe. I'll just fit the Febi one though.
I think the plastic ones fail due to being left on the car for too long?.......if pump is changed at same interval as belt then shouldn't be an issue in my opinion.
Heat cycles and corrosion is what'll ****** it.

I did a bit of reading prior to this and some think bearing failure is more likely on pumps with metal impellor.....who knows?!

[Rubberdubber]

I am sure I read somewhere that metal was not necessarily best anyway. Given the choice I would have gone for metal but apparently it puts more strain on bearings and seals due to the additional weight, so the pump is more likely to fail due to leaks. The plastic ones on the other hand will spin forever almost but the plastic blades will become brittle at some point, break off and you won't actually be pumping anything. Best bet seemed to be t go for plastic and just change them whenever you have the belt of, for whatever reason.

[peter20vt]

waterpump

I am sure I read somewhere that metal was not necessarily best anyway. Given the choice I would have gone for metal but apparently it puts more strain on bearings and seals due to the additional weight, so the pump is more likely to fail due to leaks. The plastic ones on the other hand will spin forever almost but the plastic blades will become brittle at some point, break off and you won't actually be pumping anything. Best bet seemed to be t go for plastic and just change them whenever you have the belt of, for whatever reason.

i do not know about these pumps
but on the 1.8 t the plastic wheels cam loose onn the shaft bbecause they crack
i have seen it a lot of times
some times the wheel looked like it exploded and all the plastic pieces in the engine block
what can block cooling channels

[veneto rs2]

i do not know about these pumps
but on the 1.8 t the plastic wheels cam loose onn the shaft bbecause they crack
i have seen it a lot of times
some times the wheel looked like it exploded and all the plastic pieces in the engine block
what can block cooling channels

True regard the 1.8 engine
Had the plastic inpeller coming loose on my wife Cabriolet with the 1.8 ADR motor
What a nightmare the symptoms were of a blow head gasket!

[sailaz]

Looking at the the picture, just trying to figure it out logically, the ones with more blade count will create more pressure/movement in the liquid per revolution than the ones with a smaller count. Hence there will be more flow & better cooling. But, I'm no propeller design engineer, so this is just a speculation.

Also, with bigger blades, the resistance of the liquid on a single blade will be stronger, than on the smaller one. But then again it might not be the case for the entire impeller. Bah, go ask an engineer.

I will trust engineers without asking. And I'm going to use HEPU water pump (metal blades) with RS2 pulley.

P.S> still strange, why originally RS2 water pump had plastic blades and at the same time I5 diesel engines had metal ones shape of blades was +- the same and the same amount of 5 blades ...