Nevo Crank Pulleys Cracking.

[Poggy]

Hey Everyone, Okay heres my story. I Bought a second had Nevo 175mm crank pulley for my brother in law's gze, i already have one on my gze. So when it arrived i noticed a hair-line crack along they outside of the keyway, only noticable with close inspection.
This is the only crack on the whole pulley.


Now after seeing this crack it got me thinking, i wonder what mine is like, so i took mine off and heres what i found






Any feedback? mabye everyone should check theres, one of theses suckers exploding at 8000rpm would not be friendly.

[Poggy]

Putting any of theses back on the car would just start a time bomb wouldnt it?

[Draven]

Putting any of theses back on the car would just start a time bomb wouldnt it?

with a short fuse

[MWP]

Give Nevo a call, they shouldnt fail like that no matter how old they are.
They should replace it.

[Billzilla]

Give Nevo a call, they shouldnt fail like that no matter how old they are.
They should replace it.

NEVO is no more unfortunately. John closed it down a while ago.

[Poggy]

NEVO is no more unfortunately. John closed it down a while ago.

Yes unfortunaty you speak the truth. Even the first pulley with its small crack will end up like my one? any light into why it happens? possibly thoses outer holes aroudn the main hole?

[Billzilla]

Yes unfortunaty you speak the truth. Even the first pulley with its small crack will end up like my one? any light into why it happens? possibly thoses outer holes aroudn the main hole?

Nah cracks = baaaad.
Bin 'em sorry.

No realy idea why they have started cracking, it could be a number of reasons.

[Poggy]

Nah i'm gonna bog em, spray em and sell em on ebay

[Cuzzo]

no more sc12 booosst for you

that sucks man.

maybe get a pulley machined up the exact same? probably pricey though.

[oldcorollas]

loose crank bolt.. letting the keyway smash until it cracked?
both have keyway damage.....

[Poggy]

loose crank bolt.. letting the keyway smash until it cracked?
both have keyway damage.....

bolts were rattled up though

[fixeruperer]

nevos always crack mainley becuase there solid, but in saying that ive had a few standard ge/gze ones crack aswell on the keyway.
i got a pulley my old gze pulley and machined up a ring to slip over the keyway so it cant open up anymore and machine down the ribs for the sc belt then spun up a bigger (180mm total) ribbed ring to heat slip over the standard pulley and grub screw it in.
other than having to machine down my water pump pulley to fit all was good and recieved a good canning for 4 year and still going strong on new owner.

[oldcorollas]

bolts were rattled up though

unless they were done up too tight, and the mating faces of the pulley, crank and bolt were not 'true' perhaps??

the cracks have started from the keyway. the keyways have damage from the pulley moving around the crank.. so the key has damaged the pulley (or so it looks from those pics)... considering the amount of power needed to drive the SC (30-40hp?) it would be easy for the pulley to slip around...

would vibration cause radial cracks like that?

[allencr]

bolts were rattled up though

Were they rattled down too?
Any idea of how tight they were when removed?

So it's another cause/effect thing, cracking from movement, or cracking then movement.
No damper doesn't help it, and even though it's pretty low mass, it's all on the outside.
I don't think cracking would cause as much movement as the fretting on those surfaces shows, and that first it loosened up, then chewed up the shoulder & cracked the keyway,
not cracking then moving around..

[clubagreenie]

Try ross harmonic balancers in blacktown, search the forums for harmonic balancers I've posted the contact details many times, they may have a replacement off the shelf or can make/duplicate just about anything, alloy or steel (pref for your app). And could even make it dampened probably.