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.
Have you asked Craig Conley about that ? His thoughts would carry the most weight in my opinion.Quote:
Originally Posted by SN60 Boost
I would think the race would have to be matched to the balls...
Z
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!!
I have installed the ceramic balls and bearings and made some tests. Blower sounds quiet and turns very smooth. I did not replace the output shaft or large races. They show the usual markings from normal rotation forces. There was no increase in blower boost levels. Levels stayed the same. Steady 5 lbs of boost at 5,000 and holding 6 lbs at 6000. That was expected and pretty much a given. No gauge slippage noted. Same pressures however as with the steel balls. Blower temperatures after tests (engine off) showed radiator at 178. Intake runners 175 to 180 depending on runner. Cylinder head 195 to 180 depending on location. Blower casing at 130-135 depending on location. A zapping of the fluid (via the dipstick tube) showed 130 degrees. Hat bonnet temperatures around 115 degrees. Don't know how much the blower temperatures are under driving load conditons. These were taken after street tests and after engine shut down. I regret not making a steel ball blower case temperature test before the conversion. Sensor was a HF infared device.
I like the conversion and do not regret the high dollar investment. Should last forever now. Blower rotational inch lbs was 30 to start rotation. With the steel balls it was closer to 35 inch lbs. This is about as scientific I can get at this point.
Forgot the pictures.
Are you running an oil cooler on it? Id love to put those balls in my vr-4 along with the races!
My vr-4 gets hot even with an oil cooler on it! If I even take it out on a 75💖 degree day it better not be into town and it better be at least 55 mph I'm going!
No oil cooler and at this point I don't believe it will be necessary. Pretty sure it is not slipping internally based on steady pressures on the gauge and not getting above 150 (guess) in temperatures when boosting. Might actually be cooler than 130 because on shut down there is heat soak creep of temperatures. Perhaps I should add an on board temperature sensor to the blower casing to see. I've heard the VR-4 is hot because of the very high pressure plate loads on the steel balls. So, yes, ceramic balls nitride would be a big help on those units and that should allow less pressure loading requirements I would think. Perhaps you can be the test mule on that theory.
My fluid is nonsynthetic B & M Trick Shift.
Craig at p.w set my vr-4 at 44 in lbs rotational torque not a whole lot more than the standard setting of 33 to 35? ln lbs aint nothing I torqued little screws on scope mounts to 22 in lbs.
I want the sythetic drive balls and bearings can you put the part numbers for the drive balls up please?
Don't have a part number. You have to contact the manufacturer. Here is a link. They offer the correct size in Grade 5.
Colin ChenSales Engineer
XZ Bearing Industry
www.ceramicballbearings.cn
i only have about 150,000 miles combined experience with the SN-60 units spread over 25 years and 5 or 6 GT350's and 289 K codes. If you are looking for longevity from the blower head unit, then an auxillery cooler is a necessity, not an option. You are on the right track with the B&M Trick Shift. However, the synthetic version will give you superior protection and wear resistance.Quote:
Originally Posted by SN60 Boost
I used a cooler and the synthetic B&M exclusively in my last vintage Paxton equipped '66 GT350. When I sold the kit I had about 8 years & 75,000 on it. I sent it to Craig for inspection and refurbishing as needed. He reported It didn't need it. The balls and raced were in unusually very good condition for the miles and usage. He did replace them as a matter of course, along with the new seals, but he emphasized that it was only done since the new owner was located far away, and for peace of mind mainly.
Kits that dont have superior cooling don't last half as long.
Z.
Well I have to rebuild my vr4. I thought about a new blower, I looked at the vortech forums and no thank you! 52000 max r.p.m but then a guy from vortech said don't go no more than 45000. So I'll keep my ball driven vr4 and make 11 psi
Also I truly want to go with the ceramic balls in it so how are this working out for you??