SC oiling hole revision. Has it shown improvements in bearing health?

[68ragtop]

Just curious if anyone has heard if the oiling hole that was added in the SC housings in past years has been shown to improve the bearing life in them? I have a a core SC that has the hole, but ironically lost the gear side bearing and ruined the housing. Finally rebuilding the housing I got from Ski d00 & thinking about adding the hole while its apart. Looking at the hole it pretty much lines up at 9 o'clock below the oil spray nozzle & appears it catches some of the run off.

Any thoughts? My guess is there would be no disadvantage to adding the hole if placed it the same location & I would think it help get oil to the impeller side bearing, but just looking for confirmation of my thoughts before I put it together

Thanks!

 

[nateccnn]

I have a matching pair of 2007 Wake SC. One Supercharger has the oil hole and the other does not. It's possible that the owner before me had one of the SCs replaced since the one with the oil hole also had the newer metal washers in it.

I wondered the same thing as you. Should I drill a hole? I opted not to but I am watching this thread in interest.

Nate

 

[68ragtop]

I decided to add the hole. It sure can't hurt I'm thinking. the only oil the impeller side bearing gets is what passes through the gear side bearing. It probably gets enough without it, but I decided to add the hole anyway. Seems both bearings are known to fail, & no doubt the gear side bearing gets plenty of oil if the nozzle it working correctly. Even though the bearings come sealed in bags in the kit, I still clean them, blow them out & oil them making sure my environment is spotless. I think assembling them ridiculously clean is important to a longer life.

 

[Sea Dood]

That hole on the later units has nothing to do with oiling, it has the opposite of what you think. It is to drain oil buildup. The idiots at Rotax had no clue when they made the first 4 tec engines how the supercharger gets lubed. They put a spray nozzle on the PTO in a vain attempt to direct oil flow to the washers to cool them, not realizing it don't do chit. That whole assembly gets more oil flowing over it due the slinging off of the flywheel, and that oil gets forced thru the front bearing and oil builds up in the center cavity of the supercharger. It needs oil in there to lube the impeller-side bearing, but when too much gets in there, it makes its way out the seal behind the impeller and gets sucked into the engine, even building up on the intercooler. That is why they finally put a hole in the center cavity, to let the oil escape if it is over the lower bearing race level.

In 2008, they finally woke up and realized the washers cannot effectively be cooled by oil splash from the outside, so they redesigned the spray nozzle to point into the end of the SC shaft, which was cross drilled with an outlet behind the washers. Centrifugal force lets this oil work thru the washers to cool them. A lot of guys have the misconception that this 2008+ mod is there to oil the bearings; it doesn't at all, it is only there to cool the washers.