When I had my SN-92 off the bracket, I noticed it is difficult to turn by hand. It turns, just requires some force . Is it supposed to be like this?

The blower works great on the car and really makes good power.

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91 Formula
305 TPI 5speed
1LE/G92/WS6

Paxton SN92 polished kit, SLP airfoil, ported/polished plenum, March pulleys, Crane AFPR(43psi),Crane Gold 1.6rrs,MSD coil,MSD6AL,MSD boost-master,Holley 9mm wires,Ac delco R43ts plugs,custom chip,Ford SVO 24# injectors,Bosch O2sensor, Bosch in-line pump(w/stock pump), SLP 1 5/8" headers,SLP catback,short shifter,3:73s w/Auburn posi,170* t-stat,JET 195* fan switch, Macewen white face gauges, Autometer gauges, Zoom hi-performance clutch.

 

Yes it should be hard to turn by hand.

 

Yes, it should take several inch pounds of force to turn it over. It should turn somewhat smoothly however, with even force throughout it's revolution.
Also if not rotated at least once every six months, the bearings in the ball drive can flat spot. If it gets bad you can even feel it by hand when rotating the pulley But if it hasen't been stored for extended periods without rotation then that shouldn't be a problem.

Tight & smooth is normal.

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Tracy /AKA IROCKZ4me
'86 IROC-Z Camaro
"Cogito ergo zoom"

• 355 cid
• AFR heads
• Arizona Speed & Marine hydraulic roller cam w/ AFR hydra-rev kit
• modified SLP runners
• TRW forged pistons/ceramic coated
• fully balanced
• Edelbrock headers/ceramic coated
• SLP cat-back
• Paxton supercharger
• Nitrous Express nitrous oxide

My IROC-Z
EFI Performance Club on Yahoo
Club IROC-Z

 

Well it was stored for a year on a shelf. It did have fluid in it the whole time though.

THe blower seems to work fine though. How would I know if it is not running optimal and in need of a rebuild? Lack of boost? Funny noises?

[This message has been edited by theformula (edited February 23, 2001).]

 

My SN92 and SN2000 both were very difficult to turn by hand.

My SN92 required two rebuilds in two years. The first time, it made a squealing sound. It was covered under warranty. The second time (less than one year later), it sounded similar to electrical arcing. It was not under warranty this time.

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Willie

Supercharged 1987 305 IROC-Z, Daily-Driver, Emissions-Legal.
Paxton (6-psig): 12.57 @ 111 mph.
Paxton (6-psig) & 50-hp nitrous: 12.04 @ 114 mph.
ATI D1SC (10-psig): ?

http://willie.camaro-firebird.org/

1987 "20th Anniversary Commemorative Edition" Z28 Convertible -- Super Chevy Show Class Winner, 1998.

[This message has been edited by Willie (edited February 23, 2001).]

 

The guy at Paradise Wheels said that if the bearings where flat spotted badly then you could feel it when turning the pulley by hand, but they could be mildly flat spotted and you would have no way to tell except by premature ball drive failure. Fluid wouldn't prevent flat spotting, it is caused by the extreme pressure of the ball drive assembly. If it was only stored a year you may not have any problem. He may even have turned it over by hand some time durring that year anyway.
I had one of these things stored away about 4 years once and didn't turn it over any and it flat spotted badly. That might explain some of the early failures of these units. Sitting in a warehouse or on a shop shelf sealed in a box for a couple of years could cause problems. If you bought an SN93 that was made in say 94 but you bought it in 98 or 99...

------------------

Tracy /AKA IROCKZ4me
'86 IROC-Z Camaro
"Cogito ergo zoom"

• 355 cid
• AFR heads
• Arizona Speed & Marine hydraulic roller cam w/ AFR hydra-rev kit
• modified SLP runners
• TRW forged pistons/ceramic coated
• fully balanced
• Edelbrock headers/ceramic coated
• SLP cat-back
• Paxton supercharger
• Nitrous Express nitrous oxide

My IROC-Z
EFI Performance Club on Yahoo
Club IROC-Z