928 Motorsports Water Pump Block Repair
10-13-2009, 05:49 PM
#1
Developer
Thread Starter
928 Motorsports Water Pump Block Repair
What a time for me to introduce this! I see a couple posts about damaged blocks caused by water pump failures, and then Greg Brown's excellent post of his volute repair process.
I just finished development of our volute repair process. I had no idea anybody had a fix for a damaged water pump volute, or I would have probably not developed this one.
Oh well, there are some differences, and you (the 928 owner) get the wonderful benefit of being able to choose from more than one solution.
BACKGROUND - Although the impeller is located in the bolt-on part of the water-pump, the rest of the water pump – the volute – is cast into the front of the block. And when the water pump bearings fail, the impeller often gouges into the block as shown here.
We have developed a proprietary process for re-casting the water pump volute in the block that restores the exact original dimensions and coolant flow to the engine. Our process casts a new volute over the injured one, with modern and temperature-stable metallic resins. It bonds extremely well to the Alusil block, and to any of the factory synthetic resin coating that remains.
Our re-casting process can only be done here on our premises, and cannot be done with the engine in the car. Sorry. I think this is where Greg's process may have an advantage. On the other hand, our process recasts the volute back to exact factory dimensions and distance from the impeller.
A 928 bare block in a heavy cardboard box with padding will weigh about 100 pounds, and they ship via UPS ground. Turn-around time is about 1 week on this repair. At this time, we charge $165 for this service.
I just finished development of our volute repair process. I had no idea anybody had a fix for a damaged water pump volute, or I would have probably not developed this one.
Oh well, there are some differences, and you (the 928 owner) get the wonderful benefit of being able to choose from more than one solution.
BACKGROUND - Although the impeller is located in the bolt-on part of the water-pump, the rest of the water pump – the volute – is cast into the front of the block. And when the water pump bearings fail, the impeller often gouges into the block as shown here.
We have developed a proprietary process for re-casting the water pump volute in the block that restores the exact original dimensions and coolant flow to the engine. Our process casts a new volute over the injured one, with modern and temperature-stable metallic resins. It bonds extremely well to the Alusil block, and to any of the factory synthetic resin coating that remains.
Our re-casting process can only be done here on our premises, and cannot be done with the engine in the car. Sorry. I think this is where Greg's process may have an advantage. On the other hand, our process recasts the volute back to exact factory dimensions and distance from the impeller.
A 928 bare block in a heavy cardboard box with padding will weigh about 100 pounds, and they ship via UPS ground. Turn-around time is about 1 week on this repair. At this time, we charge $165 for this service.
10-13-2009, 07:33 PM
#3
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Nice, Carl! For anyone with an engine apart I would say thats a good answer.. That means nobody should scrap a block because of impeller damage, in or out of the car!
I didn't know the factory put any kind of resin on there to start with-...
Steve
I didn't know the factory put any kind of resin on there to start with-...
Steve
10-13-2009, 08:08 PM
#4
Rennlist Member
Incredible! Here we have a very rare (by the numbers) automobile, with an unusual failure mode, and TWO solutions!! And this is against a background of a number of other similar situations where enterprising individuals and organizations have stepped up to the plate to keep these remarkable cars running. What a planet!
10-14-2009, 06:04 AM
#5
Developer
Thread Starter
I didn't know the factory put any kind of resin on there to start with-...
It doesn't corrode and its chemically stable, thats for sure. Even after constant submersion and heat cycling for 200,000 miles.
10-14-2009, 12:38 PM
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Carl thats interesting- I haven't seen it before. My car didn't have it, nor does the block I have here. Is it in all the blocks you've seen? I guess it doesn't matter- if the impeller hits the block, its going to remove material, no matter what it is.
Anyway, another nice service you offer there..
Steve
Anyway, another nice service you offer there..
Steve
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10-14-2009, 09:42 PM
#8
Former Vendor
Carl:
That's a great looking repair. I looked at all the engines I had here and they all appear to just be aluminum. But that should not matter...a good resin should work fine. Nice work.
That's a great looking repair. I looked at all the engines I had here and they all appear to just be aluminum. But that should not matter...a good resin should work fine. Nice work.
10-15-2009, 03:40 AM
#9
Under the Lift
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Looks very nice Carl! The damage sample you show seems to be a rather shallow partial cut, although it must have sat around almost forever judging by the amount of rust deposit. Anyway, it appears the repair in this case would be a thin skim coat. Have you done any deeper repairs?
10-15-2009, 04:35 AM
#11
Rennlist Member
Carl,
As the block must be out of the car, the thought of repairing thrust bearing failure (TBF) girdle surfaces flashed before my eyes. Does this "super glue" have adequate mechanical properties to address that issue?
10-15-2009, 06:20 PM
#12
Developer
Thread Starter
No Garth, I would not trust this or any other non-mechanical repair on a thrust bearing failure. Given the forces at work there, I think a mechanical remedy would be the only way to go.
In the case of the water pump volute, the epoxy resin has no direct forces upon it. On a TB journal, it would have to withstand actual thrust loading and I feel pretty certain it would detach.
In the case of the water pump volute, the epoxy resin has no direct forces upon it. On a TB journal, it would have to withstand actual thrust loading and I feel pretty certain it would detach.
10-15-2009, 06:28 PM
#13
Developer
Thread Starter
Bill,
I have not had the chance to perform this repair on a really deeply gouged block yet. We dont expect any differences, in fact, we expect the repair to be better. On this repair (shown) while the resin had the opportunity to key into the damaged areas, it was just a wipe coat and very thin on the undammaged areas. That actually made this repair more difficult.
On a test block we tried to remove this material with a cold chisel. We could only dent it, the attachement to the alusil was so good we could not chip it off.
I have not had the chance to perform this repair on a really deeply gouged block yet. We dont expect any differences, in fact, we expect the repair to be better. On this repair (shown) while the resin had the opportunity to key into the damaged areas, it was just a wipe coat and very thin on the undammaged areas. That actually made this repair more difficult.
On a test block we tried to remove this material with a cold chisel. We could only dent it, the attachement to the alusil was so good we could not chip it off.
10-16-2009, 04:50 AM
#14
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Bill,
I have not had the chance to perform this repair on a really deeply gouged block yet. We dont expect any differences, in fact, we expect the repair to be better. On this repair (shown) while the resin had the opportunity to key into the damaged areas, it was just a wipe coat and very thin on the undammaged areas. That actually made this repair more difficult.
On a test block we tried to remove this material with a cold chisel. We could only dent it, the attachement to the alusil was so good we could not chip it off.
I have not had the chance to perform this repair on a really deeply gouged block yet. We dont expect any differences, in fact, we expect the repair to be better. On this repair (shown) while the resin had the opportunity to key into the damaged areas, it was just a wipe coat and very thin on the undammaged areas. That actually made this repair more difficult.
On a test block we tried to remove this material with a cold chisel. We could only dent it, the attachement to the alusil was so good we could not chip it off.
