maXbimmer Forums

maXbimmer Forums (http://www.maxbimmer.com/forums/index.php)
-   General Discussion (http://www.maxbimmer.com/forums/forumdisplay.php?f=2)
-   -   Water pump impellers. Metal vs. plastic (http://www.maxbimmer.com/forums/showthread.php?t=151302)

DR.ZED 06-04-2012 04:34 PM

Water pump impellers. Metal vs. plastic
 
Ran across this. Interesting.....

http://www.blauparts.com/audi_water_...ntroversy.html

Click the video.

5style 06-04-2012 05:57 PM

bullshit. Metal > Plastic shit, end of story

Axxe 06-05-2012 12:55 AM

To be honest, I wasnt impressed with the impeller design on the metal impeller pump I put in my car. The plastic unit I replaced had a significantly smoother profile and what appeared to be a higher efficiency design. But everyone runs the metal units without issue, not so much with the plastic unit. I just dont trust plastic components in my cooling system, the only plastic I have left is the HVAC system.

Steve30 06-05-2012 01:04 AM

the only metal impeller pump you should go with is the stewart.

Axxe 06-05-2012 01:08 AM

Next time ;)

SiR 06-05-2012 09:30 AM

quality varies with some of the metal replacement pumps(some of them bad)...but still better than the composite ones.

rdc 06-05-2012 10:49 AM

They have the same debate over at the Porsche Boxster forums. There's reports of the plastic water pumps impellers disintegrating and bits of the impeller getting lodged in the cooling system. There's also reports of metal impeller water pumps failing and the metal impeller grinding away at the aluminum engine block. I guess you through the dice and take your chances. As for me I just replaced mine with a BMW water pump. Maranello discounted of course *th-up*

ScotcH 06-05-2012 02:51 PM

Yup, we've seen the el'cheapo metal ones fail. The ones that look like they're made of tim foil and soldered togther are shit. The cast metal ones are good. The Stewart racing one is the best. The new ones from BMW are supposed to be made of different composite, and are lass prone to failure ... don't have any 1st hand experience though.

DIY 06-05-2012 11:13 PM

plastic doesn't corrode ... but will if your system isnt bled properly, if there is any air in the lines it will corrode anything in time... however if were talking about structural failure I guess metal will hold up better to the heat... But I havent had to change mine yet so I havent had a chance to see

Blackedout95 06-05-2012 11:59 PM

Metal everyday, replaced many plastic one's, none metal yet due to breaking apart like the plastic. The plastic will break, just a matter of time.

However while some models get metal now from the dealer that originally came with plastic, many newer models still have plastic, go figure.

SiR 06-06-2012 10:16 AM

the composites have come a long way but they are still a cost cutting measure...something the video forgets to mention. derp the engineers tested it all and the brightest minds chose composite...errr thats not exactly how manufacturing works.

$$$ has a very important role in the decision making process.

Dinanstu 06-06-2012 10:38 AM

Improved bearings, better flow, better construction and better quality SS impeller is the Stewart water pump....

There is more to pump dynamics than the impeller, having said that - you won't find many plastic impellers in industrial applications.

Maple 06-06-2012 09:53 PM

Plastic/composite all the way.

You can not beat lightweight and technology advancement, hell even oil pans are now plastic . Its all because of the fact that plastic technology advances and Im very glad it does.

Cast metal WP are too heavy for the bearings and the bearing will eventually give out, much sooner then a plastic impeller will ever break. Before I put a Stewart in my car , my original plastic water pump had over 150k kms on it and still worked fine, on my other BMWs the plastic water pump impellers lasted 160 and 145 k kms. Good enough for me

Dinanstu 06-07-2012 07:21 AM

Quote:

Originally Posted by Maple (Post 1569841)
Plastic/composite all the way.

You can not beat lightweight and technology advancement, hell even oil pans are now plastic . Its all because of the fact that plastic technology advances and Im very glad it does.

Cast metal WP are too heavy for the bearings and the bearing will eventually give out, much sooner then a plastic impeller will ever break. Before I put a Stewart in my car , my original plastic water pump had over 150k kms on it and still worked fine, on my other BMWs the plastic water pump impellers lasted 160 and 145 k kms. Good enough for me

This is the most ridiculous thing I have ever heard.

...I think we'll change all our pumps to plastic impellers at work here, so to take the load off the bearings and save money....I mean what do engineers know about roatational and vertical forces and heat on bearings?
...Good luck with your plastic, high tech impeller...*wave*

SiR 06-07-2012 02:21 PM

your car has all kinds of bearings that have to deal with a lot more weight/force....

sure bearings wear out but plastic fails a lot more than the bearing wears out.


All times are GMT -4. The time now is 11:57 AM.

Powered by vBulletin® Version 3.8.1
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.