cw383

iTrader: (6)

I have the ATI damper for LNF, its the underdrive one. I noticed when I took it out of the box the crank hub is the same, but the belt grooves are for 8 grooves vs the 5 grove on an LNF damper. My thoughts are maybe its a dual setup for LSJ and LNF cars. Do LSJ's use an 8 groove belt? And does it do any harm using a 5 grove belt on an 8 groove pulley, provided its on last groove in factory position?

cw383

iTrader: (6)

Answered my own question. Found it on ZZP website. Works with both!~

TurboWood

Don't forget to hone the pulley before installation.

Daniel

cw383

iTrader: (6)

Good point, how did you hone yours?

JapEatr

iTrader: (9)

do not do this... it is designed to be an interference fit.

Omiotek

iTrader: (2)

You should be extending your keyway as well.

ItalianJoe1

iTrader: (10)

Yep, just came across this the other day and this thread reminded me of it.


At the 4:20ish mark he talks about boiling the ATI hub in water to warm it up, then slide it on the cold crank. It's designed to be that tight.

TurboWood

JapEatr,
Honing the pulley is in the ATI instruction sheet that comes in the box. Maybe some people get lucky and the fit is perfect, but I assure you that mine is not. I suspect all LNF pulleys need to be honed, but it should at least be checked.

Notice that I did not say to remove the press-fit. You simply want the correct interference.

This is where my parts are (have not done thee install/honing yet):

Crank diameter: 1.102"
Pulley I.D.: 1.099"
Specified Interference target: 0.0006"-0.0012"

As you can see my interference is currently 3thou, but the spec is a max of 1.2thou. Now I could just heat the hub of the pulley up to get it on, but I would like to be able to remove it in the future and 3thou is a lot in a 1inch diameter.

My thread about this topic: https://www.cobaltss.net/forums/2-0l...quired-319046/

ATI instructions: http://www.atiracing.com/instructions/Super-Damper.pdf

Daniel

Omiotek

iTrader: (2)

Getting the proper interference is what you need. Some might require a hone some might not. It really depends on how tight it really is. Tolerences vary

Its still a good idea to extend the keyway for the ATI so i hope you did it.

TurboWood

Tell me more. Why is this important?

Daniel

Omiotek

iTrader: (2)

the stock keyways sometimes sheer off so usually with the atis we extend them to the end of the crank. its just a failsafe.

TurboWood

Is this specific to the ATI pulley or have you seen it sheer with all pulleys? Is it a result of high power?

Thanks,
Daniel

taintedred07

iTrader: (1)

Hope my crank is ok...