Anyone using or testing these SN-60 or VS-57 units with the new tech ceramic silicon nitride bearings and balls? Thanks.
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Anyone using or testing these SN-60 or VS-57 units with the new tech ceramic silicon nitride bearings and balls? Thanks.
My research shows they are making hybrid bearings with only the balls Si3N4 and the rest is steel race. The properties of ceramic balls would help the problems of high temperatures and centrifugal forces of the 1.0625" steel balls. I weighed a steel ball and it came in at 80.1 grams. Some data specs list the steel ball at 90 grams each. Silicon Nitride ceramic balls are nearly 60% lighter, much smoother, harder, and can take far more rpm and temperatures.
Might solve the high pressure loading requirements of the internal spring clutch or shim plate race also. Blower friiction and hp drag should go down a lot and blower run far cooler too. Hoping to go ceramic on the input bearings and driver balls for a test but curious if others have experimented the design change.
You've raised an interesting question here.
What's the price of these silicone nitride ceramic balls? If there's a significant price increase versus the 'standard' steel balls, that might explain why we haven't seen them used.
Boca Bearing lists a 1-1/16" ceramic balls for $74.95 each. Closer inspection shows they are ZR02 composition and weight is 62.83 grams each. That made for a 21.6% lighter ball. Talked to another place and they recommended Si3N4 ceramic for any automotive use, but didn't have the size. Had plenty of 1" and 1-1/8" etc. Cerbec said they had 36 balls in their system and quoted $145 each. Very expensive but their data specs listed them as grade 5 and 26.9875 mm sphere diameter. Said the oil companies use them as a check valve sort of thing. An insignificant cost to an oil company.
The density mass of Si3N4 is 3.21 grams/ cm3 and steel is 7.85 grams / cm3. based on one data sheet I found from the school of internet surfing. Thanks for the interest.
First replacement upgrade bearing has arrived. Still waiting on the second larger bearing for the input shaft. Attachment 1962
Sweet! Keep us posted - I'm very curious to see if you notice any benefits from the swap.
BTW - how much did that bearing cost? And where did you get it? I'm still in the process of reassembling my own SN89, so if the cost isn't too bad I may follow your lead.
Came from VXB Bearings. They have full and hybrid ceramic bearings. I went with the hybrid for now.
http://www.vxb.com/page/bearings/PROD/Kit7796
http://www.vxb.com/page/bearings/PROD/Kit7680
http://www.vxb.com/page/bearings/PROD/Kit111126
Only question I have is that the impellershaft has become the weakest link.
I believe heat is what it kills in the first place.
The ceramic balls arrived. Weighted one and it is a full 60% lighter than the steel balls. They look nice and grade 5 quality. Still waiting on the last bearing. Then the rebuild can start. The race and output shaft look good and though not new should work fine since the unit turns smoothly now with the steel balls at 33-35 inch lbs. Not expecting the turning pressure to change but believe the same pressure will keep the balls from unloading off the output shaft because of the dramatic reduction in centrifual forces pushing against the pressure plate springs. If the blower can survive more rpms and not unload off the output shaft then the investment will pay for itself.
Your logic sounds correct with respect eliminating unloading off the output shaft due to lower ball weight/centrifugal force, but I don't think you'll gain anything by spinning the blower any faster. These old SNs shouldn't be spun beyond around 40,000rpm. Spin them any more than that and all you get is more heat.
But you've got me very seriously considering ordering up a set of these ceramic balls and bearings. I can't really see anything negative to doing this, other than the cost.
Did you test the supercharger out with the ceramic balls?
Not yet, I am bogged down with home improvement projects and other "cares of this life." Still several months away at the current pace.
This sounds like an great idea - wish you all the best with this experiment! Regarding ceramic, the main advantage beside the weight is the low friction !!!! - AND this is what do not want to have in a ball drive. I think we need a high coeffizient of friction. Sometimes the real world is different from what we have learned. In this case i really hope i am wrong.
I hope it works!!