ROG100

There are only three new WP's available - Laso, Porsche and Hamburg Technic.
My money is still with Laso (based on numbers sold) and once they start with the ABS impeller they will be number one in my book.
Not perfect but the best choice by far.

Marine Blue

These failures are simply unacceptable! Dwayne sorry to hear about this. I hope you're able to make the necessary repairs and get the block back in spec.

Seems right now the only pump that is reliable is the OE Porsche Pump although I've heard these can also fail.

We all need to come together on this and look for a reliable alternative.

Dwayne

This option sounds pretty good to me....any idea when the ABS version of the Laso will be available??

ROG100

Dwayne I will find out from their MD asap.

The Porsche new pump based on averages is way down the list. They sell very few compared to the Laso and they fail. You sell 100 pumps and two fail thats not good. You sell 100'S and one fails thats better. Not perfect but a step in the right direction.
I am not aware of any failures with the new Laso pump.
Laso is the only company with any interest in our plight and is moving towards the perfect combination.
Cost, new, plastic impeller.
Remember MPG the Porsche pump manufacturer has no interest in changing anything with their 30 year old design.

Thanks again to Greg and Steve for the fix.

Dwayne

I've measured the depth of cut. It's just shy of 1/8" or about 3mm. If I can't repair the block while in the car, I'll probably try fitting a new WP and see what affect on engine temp there is with the 3mm gap - should be interesting!

smudaaar

All you need to do is tig weld the impeller to the shaft. This is how most 2 stroke crank shafts are help together!

Dwayne

Roger,
Thanks for the quick response. I'll stand by. If Laso will have the "perfect combination" available by the time I can repair the block, I'd like to get that version. If not, I would like to find out more on the "new Laso" version, especially if it has no reported failures. I like the idea of using the plastic impeller but if there's a metal impeller version available with the lowest failure rate of all, it's worth considering. THANKS!

blown 87

That will not help in some cases, mine did not move on the shaft, the whole thing moved.
At least that is what it looked like to me, I will defer to Greg Brown to say exactly what happened to it, he has my old pump.

worf928

But, they do have a plastic impeller. I have a new Porsche pump in a box as I type this.

If that's how you want to spend your time I won't stop you. But, IMO, you will see increased operating temperature with that much gap. BTDT and had to do it again.

Dwayne

I didn't realize this had already been tried. Was your depth of cut/damage similar to mine (about 3mm)?? I'm curious how significant the increased temperatures were. Since you had to do it again, I'm assuming they were significant - yes?? What was your final solution? THANKS!

Mrmerlin

Sorry to hear this Dwayne, Greg has a fix for this check it out, it looks like its the best way to remedy the situation, then fit a different water pump

Bill Ball

It does not appear that the impeller slipped in this case, or did it?

Dwayne

Right, Bill. The impeller is flush with the shaft so I assume the shaft itself moved outward.

worf928

IIRC, it was about 2 - 3mm. If you take a look at the other threads on Impeller Block Machining (IBM) there's more info.

This was on an '87 so I can't give you Hammer-reported temps which would be my preference. But, after the fix, temp needle went from just above the last white line to just below the last white line (where it should be) and IR measurements at the NTC-II went from ~205°F to ~195°F (again, about where it should be.)

So, the IBM'd block seemed to result in about 10°F higher temps at the water bridge. Some folks might be able to live with that. The owner of the '87 in question didn't want to.

Years ago, I did a WP on an '89 with ~1mm of IBM and its temperatures were fine with just a rebuilt pump (gulp ). The threshold seems to lie in the 2 to 4 mm range based upon my two data points.

I did the EBF - "Earl's Block Fix" using PC-7 - also covered and discussed in one of the other threads. That was two years ago, before Doc Brown R&D'd-up his way, way better fix.

ROG100

Seems like the complete seal cartridge moved within the casting.
One of the classic failures reported with rebuilds.
The interferance fit of the seal cartridge to the ID of the casting bore is compromised by repeated rebuilding without considertaion of the effect.