svp928

Greg, glad it worked! The screws should fit better in the thicker inserts, so not all will need any extra countersinking.
Who is doing the billet pump?

Bronto- a hard insert would not be practical from a cost standpoint- the hardening process would warp something that thin, so it would then have to finish-ground to size. NOW you're talking a lot of money. Short answer is , NO.

GregBBRD

Something has to be softer...either the impeller or the insert. If you run a plastic impeller, it will be softer. That's why Porsche did this.

If you run a steel impeller, the insert is softer, but can be replaced, in case you are really unlucky.

bronto

My thought was that some choose plastic because they don't want to risk drilling the block. Some choose metal because they want the performance and durability. If the insert were harder than the metal impeller, you would have both.

ew928

What type of countersunk screws will be used to hold the insert on, if I understand this correctly?
Brass is too soft? Just wondering what happens if metal impeller starts chewing on the insert and the screwheads.

svp928

EW- the same thing that happens to the block now, only you just replace the insert....

GregBBRD

Haven't seen any....and to be frank, I could have built one, with a stinking file, by now. That usually means that it's a"pipe dream" which isn't going to happen. Time to move on and get one done.

Besides that, after our discussions about Laso or Porsche pumps, our goals are clearly different. I'm looking for the very best that I can put my hands on....which is a compromise, right now. In these engines, the water pump not only keeps the engines cool, but also is needed for cam belt duties. It simply, can't be "second" best.

Reading carefully back at the two threads we've talked about pumps, your main support of the Laso pump is price only. You keep talking about needing something that you can sell to the guy with a $3000 928. I understand that. Let them buy the Version 2 or Version 6 Laso pump..which ever one works the best, the day they need it.

"Billet" means nothing to me. I've been building engines (including American engines) long enough to have bought just about every product, out there. I've had virtually every "billet" Chevy pump every created, in my hands. There's good ones....and there's ones that are complete pieces of crap....way worse than any "stock" pump.

I'm going to build pumps that satisfy my specification, which is quality, only.

GregBBRD

Potentially a good idea, but the actual need has to be really low, so i think we'll keep it like this, for a while. One can keep redesigning things, forever. There is absolutely no limit to "what if".

I was interested in "saving" damaged blocks, not tying to find a cure for every potential problem that might occur. If someone is unlucky/dumb enough to have a metal impeller come off a second time....they can simply replace the insert, when they replace their pump.

This method met my objectives and exceeded my expectations. Try to remember, the only other method that seemed to be used for this repair, before this, was epoxy.

S4ordie

Greg - because I have ordered up a stroker build for my engine where quality/performance is comensurate with high investment cost, there can be no opportunity for engine failure due to a poor component design.

I am very pleased to see this come about and I look forward to a Doc Brown designer, blue printed, CNC billet, water pump on my engine when completed.

Thanks to all in this discussion and fabrication.

ROG100

Greg,
I guess I missunderstood you some how. You stated " wait until you see our billet pump" I assumed that meant you were building one - after your post I guess I got that wrong.
Just because I sell water pumps does not mean I am not interested in what you do - I think I have made it very clear that I respect what you do immensely. One day I may want a stroker engine and will need you to build it for me.
We know Ed is making one so that is why I mentioned two billet pumps.
So we only have one Billet pump being made at the moment.
Roger

SharkSkin

Greg, that looks incredible! Very nice result. Looks like you had to fight chatter a bit. Two questions:

How will you ensure the screws stay put? Threadlocker e.g. LocTite?

I must not have my brain fully engaged... how is it that you end up with chips on the OUTSIDE of the WP? Did you cut a window in the WP casting to watch the cut? That's kind of how it looks from the pic below but it's hard to be sure:



Also, I like your idea of "blueprinting", i.e. optimizing the gap between the impeller & insert, though I can imagine potential issues if a different WP is installed later.

Fastest928

Only method was epoxy? I had welded ( I am a very good welder, but not a pro, so used a cert welder do the weld) the block and used a metal impeller (slightly modified) WP to cut a new surface. Trick was to keep the impeller/wp cutting in even increments, not trivial. Not pretty, but worked. Some work required at the edge of the cut.

I kept a small amount of metal impeller dead WP's for this purpose.

This looks like much nicer repair!!! Well done.

Fastest928

Greg,

Bob D played with removing blades to minimize potential cavitation...might consider that also when blueprinting blocks....like all BPing, the key is in the actual dimensions to BP to.

GregBBRD

Thanks, Marc.

It took a whole bunch of people to accompish this...it's one of those "group" efforts.

Yes, dismissed welding, as we were trying to get a repair that would work, while the engine was in the car and assembled....although I guess a really good welder could do this, also. Got to admire anyone that can weld on that silicone impregnated aluminum....I don't enjoy welding it, either. I completely understand about you having someone else do it...it's very difficult to get good results, with that "base" material.

blown 87

I know you do not mean to be funny, but damn man, I laughed out loud at that.

OBehave

Greg,I can understand your frustration with all you've been through but if all I had to do was make a billet waterpump,I would have.As stated months ago in one of the many of long discussions I was approaching this issue as a hobby and a love.I have spent a good amount of money, time and effort on really trying to address the issues at hand and I can assure you sir that this is no pipe dream.My daily responsibilities and lack of extra time put some delay in my working this out.I can assure you also that I have 3 cars of my own right now running on my solution to the waterpump issues and 2 of them are 32vale engines.Engine protection and longevity were the key factors for me that won't cost a fortune to produce.I have various hours and mileage on all three as we alternate driving them everyday and weekend jaunts.The costs haven't even been figured out yet because of just getting the test pumps ready and built.I just wanted to have all the answers before bringing it out.I think when all is done you and everyone else will be very satisfied with what I put forward not only in effectiveness,but in quality and price as well.Thanks for all the work you have done so far in preserving the marque,Ed