blown 87

Well done.

This is a major improvement, any body that has had a metal impeller migrate knows what I am talking about.

Dan87951

Roger,

Lets get a list started on my t-belt replacement for my black S4 we talked about. I will take one of these water pumps for $275. Also add a belt and two tensioner pulleys. What pump did I get from you when I did a belt replacement on my cassirot (late 08/ early 09 i believe)? Was that a rebuilt or new? Wow does it come with everything pictured as well?

Thanks

Giovanni

How much if we provide a core?

ROG100

Dan,
The new Laso pumps come with all the bits as per the picture - always have - so do the Factory Porsche units as well.
It was a rebuild back in May 2008.

Gio,
Initially I only plan to sell new WP's with the modification.
Ed will tell you better than I on prices.
Roger

Dan87951

I never ordered a new one from you but my rebuilt definitely didn't come with all that was pictured. I'm guessing thats for only new units, correct?

Giovanni

If I understand Ed's concept he only uses the w/p housing and rebuild it with his parts. its a shame to sacrafice new w/p just to use the housing while there are tons of cores out there.

blown 87

I don't know Gio, part of the problem seems to have been some of the cores have been built more than once and this "Loose Fit" allows the cartridge to move.

Giovanni

If that case probably someone can measure a new waterpump and have those numbers as base measurements for rebuildable cores?

OBehave

As of right now what I offer is modifying a new pump,not disturbing any of the components other than the pulley,then install my modification kit and pin the impellor. I will be offering rebuilt units when I have procured some cores and the necessary parts that go into them.I will only offer rebuilt pumps with the modification installed.
I have quite a few mod kits ready to install now,I will need some time to get the rebuilding going. Ed

OBehave

That is why I will only supply rebuilts that are modified because at that time I will be installing a cartridge bearing with the proper clearances so it doesn't move and locking it in with the drive modification. Ed

ptuomov

Volkswagen (and I assume Porsche as well) screwed up and initially used plastic that couldn't cope with 100C temperatures. Since then, they've migrated to polyphenylene sulfide which is a better choice. By my understanding, polyphenylene sulfide is a superior water pump impeller material to metal alternatives. Laso uses it in these new pumps.

My question: Given that you can cast/mold any shapes from PPS, could we get a couple of impeller choices? That is, impeller designs that are optimized for different engine RPM ranges? I think one could basically change three things; vane angle at inlet, vane angle at outlet, and the number of vanes; and still keep the pump perfectly a bolt on piece.

Now, someone who understands pump engineering could nip this at the bud and explain to me that those three design parameters don't influence the efficient rpm range and that the whole exercise would be pointless. For example, it could be that only say the outer diameter or the cross-section of the impeller impacts the efficient rpm range. I'd be grateful for such guidance.

dr bob

Worst-case interpretation... Is there a way to sacrifice low-RPM pump performance and risk overheating in traffic, to gain a fraction of a horsepower at higher RPM's due to some improved impellor design for higher RPM's?

Want to make sure I understand the question.

ptuomov

I don't know enough about how water pumps work to ask the question more precisely. I am actually looking for someone to educate me on this topic. But let me speculate, ignorance has never stopped me from voicing my opinion! ;-)

Yes, it's likely that there's no free lunch here and that one can't easily make the pump work better at all rpms. Although it is possible that a quarter century design that was economical to cast in metal is not the best we can do now with powerful computers and a material that can be cast/molded very precisely. Evans Cooling certainly claims that they can do better than stock pumps with their impeller designs.

But even if there's no free lunch across all rpms, you could have one impeller that would look like those diesel truck impellers that spin at low rpm and then another one that is maybe suited for very high rpms. I am asking if something intelligent can be done here, I am not looking to grind off three vanes from the impeller like some people souping up their diesel trucks are doing.

For each alternative impeller, you could just show a graph with pressure on the y axis, flow on the y axis, and a curve on the graph for each pump rpm. For that matter, having that graph for the existing impeller would be interesting and potentially useful.

Also, the water pump may start cavitating at high rpms. Does it, does anyone have any evidence of this? Maybe it's not a problem for our cars. If it is, can changes be made to reduce the tendency to cavitate at high rpms?

Finally, correct me if I am wrong, but the low-speed overheating is more about air flow and less about the water circulation speed. I am guessing that the radiator gets really hot in traffic, which is an indication that it's an air flow issue and not a water circulation issue. If the radiator were cool, then it would be a water circulation issue. Also, if the car overheats more at low rpms than at same load but higher rpms then maybe it's a coolant flow problem. Right?

Cooling air flow I have some intuition with, but this water pump stuff is all new to me. It's all theoretical for me at least for now, given that my car doesn't overheat in the Boston weather.

mj1pate

Roger please update as soon as you have the similar design suitable for 86.5. I was planning to do the TBelt job this winter without adding a new pump. This development prompts me to do the pump as well if the pump is available. Thanks.....

Mike

ROG100

Mike,
This is an old thread and we have both the early and late style Laso pumps with plastic impellers.
Roger