Heater valve block refurb
 

So while the engine is out of my S8 I'm going through everything to make sure it's spot on. While flushing the heater cores I noticed the motor on the heater valve block had a lot of external rust, almost like it had been underwater for a while. I wonder how that might happen :rolleyes: (yes, the drains were full of compost)

With it on the bench I took the motor off and surprise surprise it's very stiff to turn so dismantled it on the grounds I had nothing to lose. It had clearly been full of water :mad:

http://www.corradov8.com/pics/s8/motor1.jpg

http://www.corradov8.com/pics/s8/motor2.jpg

http://www.corradov8.com/pics/s8/motor3.jpg

http://www.corradov8.com/pics/s8/motor4.jpg

I reckon I can recover that...

Respect if you do! +++

So its been kind of a submersable pump then? Was it actually working!!??

No, not even a little bit! New bearings one the way...

Hmm, I was going to say respect to the motor if it was doing anything at all in that condition - but you've answered that one.

Suspect mine might look similar though the heater does work.....

Nick

Fixed it! +++

After cleaning it all up I discovered one of the windings on the armature had burned out, presumably from it being powered up while stalled:

http://www.corradov8.com/pics/s8/winding1.jpg

So carefully soldered that back together

http://www.corradov8.com/pics/s8/winding2.jpg

A continuity check across the commutator terminals showed the windings were all complete, so onward to the terminals in the end cap. These are brass, and had corroded away to blue powder. I ended up having to dig some plastic away with the dremel and cleaned up the tracks with a diamond burr so I could solder to them.

http://www.corradov8.com/pics/s8/terminals.jpg

Not a lot to work with, but I got it done.

The brush plate broke in half when I dismantled the motor, but thats no biggie. I soldered wires to the two inductors and hot-glued everything in place.

http://www.corradov8.com/pics/s8/brushplate.jpg

Soldered the two wires to the terminals in the end cap, and then assembled it with the aid of some cyanoacrylate superglue.

http://www.corradov8.com/pics/s8/endcap.jpg

You can see the bearing already in place here. Because of the way I've had to rebuild it with the wires I had to put the bearing in first and then press the motor shaft in to it in place. The factory would have assembled the brush plate and bearing first, then put the end cap on and soldered the terminals together.

I pressed the end bearing on first

http://www.corradov8.com/pics/s8/bearing.jpg

Then pressed the armature in to the bearing in the end cap and we have this:

http://www.corradov8.com/pics/s8/assembled1.jpg

http://www.corradov8.com/pics/s8/assembled2.jpg

Cleaned up the housing:

http://www.corradov8.com/pics/s8/housing.jpg

The completed assembly just pushes in to the housing by hand and screws in place.

The motor drives the pump via magnetic coupling to save on having to seal the motor shaft against pressurised coolant. The magnet is attached to this steel flange then bolted to the motor shaft:

http://www.corradov8.com/pics/s8/flange.jpg

This had obviously been underwater too so cleaned it up with a bit of sandpaper then bolted it to the shaft. The magnetic ring is glued to the flange using the same structural acrylic that I used on the body studs, and the motor is complete:

http://www.corradov8.com/pics/s8/finished.jpg

Hooked up power to it and it works again :D

And a couple of videos of it running :)

Motor running

The motor is sealed from the valve body using the aluminium plate then drives the impellers (one for each side) via a magnetic ring. The impeller next to the motor drives the one on the other side of the valve body using a slotted bush.

Motor running with impeller

(yes the meter is hooked up backwards!)

Tunes courtesy of Sanctuary Radio :rockin:

Neat work. +++

perfect

I am impressed. Don't think I would have bothered looking at what you started with tbh