Harmonic Dampened Crankshaft Pulley - OEM, Modification or Custom?

Seeking advice as I am new to FI. I recently picked up a BBSC kit and those run 6 rib pulleys as opposed to 5 rib OEM. The kit was missing the 6 rib crank pulley, but I wasn't planning on using it anyways as I want to stick with a harmonically dampened pulley like the OEM or ATI one. However, the OEM and ATI are 5 rib only. The PO of the kit ran on the OEM and after calling up SOS about their SC kits they run on the OEM as well without belt slippage issues. So would staying with the OEM be just fine?

Also, anyone know if perhaps the OEM or ATI can be machined to add a 6th rib? Is there enough metal left on either?

I did call ATI about a custom and they stated they weren't doing anymore custom for the rest of the year at least. So I asked if they had drawings from previously custom built pulleys for other Primers. The rep I talked to dug up old drawings for an 8 rib pulley, but if it is the Primer I am thinking of it required relocation of parts to make room for the wider pulley. Also they found a 6 rib but it was larger diameter, which would affect how the other pulleys were driven. So both of those are out in my mind. Anyone out there have a custom 6 rib made by them and perhaps have the drawing number?

Thanks for any info.

I used to own a 300zx and decided to have the motor rebuilt.

I took the car to the garage with all the parts including a one piece crank pulley. The garage refused to install it.

They said it doesn't matter as much on a straight 4 cylinder but on a V6 you should always run a Harmonic (damper) type pulley. They claimed the vibration from a V could do damage after time.

How true that is i do not know but it does make sense.

Hope that is of any help.

jaffaz32 said:

I used to own a 300zx and decided to have the motor rebuilt.

I took the car to the garage with all the parts including a one piece crank pulley. The garage refused to install it.

They said it doesn't matter as much on a straight 4 cylinder but on a V6 you should always run a Harmonic (damper) type pulley. They claimed the vibration from a V could do damage after time.

How true that is i do not know but it does make sense.

Hope that is of any help.

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Yes, I plan on keeping a dampened crank pulley on. I recall reading that the OEM pulley was designed to counter the resonance frequency from the engine at high revs thus protecting everything.

So unless someone chimes in on a 6 rib solution, I guess I will just buy a new OEM pulley as my original ones has never been replaced and throw on that pulley shield from SOS as well.

Don´t know if this could interest you but here you go:

http://www.nsxprime.com/forum/showthread.php/179708-Ati-damper-oil-relocation-kit

Have no conections with the seller!

I do have an ATI Damper on my car for three years now (but not more than 5.000 miles)... and I'm happy with it (shaved 1,74 lbs of rotational weight). But my NSX is NA.

BBVNSX said:

Don´t know if this could interest you but here you go:

http://www.nsxprime.com/forum/showthread.php/179708-Ati-damper-oil-relocation-kit

Have no conections with the seller!

I do have an ATI Damper on my car for three years now (but not more than 5.000 miles)... and I'm happy with it (shaved 1,74 lbs of rotational weight). But my NSX is NA.

Click to expand...

Thanks for the link. Yea I read the build thread and while very cool, I really don't want to get into relocation of oil filter and routing more hoses. Depending on when I do my BBSC install, I may call ATI again and ask if they will build a 6 rib or I will just stick with the OEM 5 rib.

I can make you a 6 rib pulley, I make them to fit on the stock OEM pulley. They end up being a few mm larger in since the new pulley track is aluminum, not enough you need to worry about clearance or meaningful change to belt ratios.

Let me know if I can help.

titaniumdave said:

I can make you a 6 rib pulley, I make them to fit on the stock OEM pulley. They end up being a few mm larger in since the new pulley track is aluminum, not enough you need to worry about clearance or meaningful change to belt ratios.

Let me know if I can help.

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Dave,

Would I need to send a stock crankshaft pulley to you to modify? Or do you build your own? Would your 6-rib still be dampened? Very interested with pairing it with your pulley shield.

I build the new pulley on a stock NSX damper, usually I start with a New part. That is way I can maintain the crank damping as Honda intended. Let me know if you want me to get a damper heading my way for your project.

Dave

Sweet. Sending you a PM!