After being the first bike up the Pikes Peak race this year, I can attest that liquid cooling does work. I just completed my winter teardown to make a few improvements. Found out I had a detached capacitor. Who knows how long I was riding like this.
Controller:
Soldered the cap back on after hearing it rattle inside the controller. Not too bad.
Siliconed each cap for vibration resistance.
Snugged the fet screws. They were ALL loose!
Spread more thermal compound on backside of aluminum fet bar.
Installed 12v cooling fan in end cap of controller.
Motor:
Installed new Japanese bearings with thin layer of silicone sealant
Re-sealed interior axle/wire slot with silicone sealant.
Tapped hole in side cover for one way pressure valve like these...
http://www.ebay.com/itm/221106438184?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
Hopefully this will work a bit better than the "tiny hole" method. I will have to stop and bleed the air once I reach maximum temperature. Hopefully the motor will be in a vacuum state after cooling, which should help avoid leaking fluid.
I bolted everything back up and I'm functional, so I didn't botch the controller, woot!
After charging my 25s 12ah battery to 4.1v/cell, I get the following results:
Edit: Working on filling in the data...
ATF Fluid level Resting V Sagging V No-Load Current Wheel Speed RPM
___________________________________________________________________________
0 ml:................102.5.....102.3............1.29...........46.4.........609.5
50ml:...............102.5.....102.2............1.37...........46.4..........609.5
100ml:..............102.5.....102.1............2.16...........46.0..........604.2
150ml:..............102.5.....102.1............2.24...........45.9..........602.9
200ml:..............102.5.....102.1............2.24...........45.9..........602.9
250ml:..............102.5.....102.1............2.24...........45.9..........602.9
300ml:..............102.5.....102.1............2.24...........45.9..........602.9
350ml:..............102.5.....102.1............2.24...........45.9..........602.9
400ml:..............102.5.....102.0............2.24...........45.9..........602.9
450ml:..............102.5.....102.0............2.24...........45.9..........602.9
500ml:..............102.5.....102.0............2.24...........45.9..........602.9
550ml:..............102.5.....102.0............2.24...........45.9..........602.9
650ml:..............102.5.....102.0............2.25...........45.9..........602.9 (this is exactly half full)
700ml:..............102.5.....102.0............2.31...........45.9..........602.9
Ran out of fluid...
750ml:
800ml:
850ml:
900ml:
950ml:
1000ml:
1050ml:
1100ml:
1150ml:
1200ml:
1250ml:
I measured the total full capacity of the motor at 1300ml using water. I calculated the thermal expansion of atf3 at 0.3% per degree C, so it really doesn't expand too much even with a delta T of 100C. Its the hot air I worry about. If I don't bleed that valve properly, or didn't seal the motor properly, I may have created a pressurized, hot oil filled, spinning electric device that I'm riding at 40mph. What could happen?