ATI vs OEM harmonic dampener

[Rainman]

My dampener I'm pretty sure is from 1991 so I need to have it replaced a maintenance item.
I'm considering the ATI dampener vs OEM Dampener plus CRF shield.
The ATI dampener theoretically has some performance benefits and is serviceable.
Replacing the OEM dampener every 9 years doesn't seem so bad either.

I don't know much about press fit but my main concern is the press fit and what wear and tear it will place on the crank being pulled off and put back on with each timing belt change.
I know this is not a super common event but as parts get harder and harder to replace but potentially damaging the crank would negate any performance benefit to me.

 

[Mac Attack]

I've put about 10k miles on my ATI. It probably requires a rebuild within the next couple of years. While it takes a little longer to remove/install an ATI vs the OEM, I'm not concerned about the wear it places on the crankshaft. The crank harmonic dampener bolt torque is 181 ft-lbs. It takes way less than that to press-fit it to the crank. I think the ATI hub is aluminum (?), which helps contribute to the lower rotating mass. You therefore run a higher risk of damaging the ATI dampener than you do the hardened steel crank.

My advice is to stick with OEM if you have a mostly stock engine. You can't go wrong with that!

 

[Larry Bastanza]

Not sure about this "press-fit" idea. For stock balancers, I remove the bolt with a good size air gun, then pull the pulley off the crank with my hand, not press fit.......

HTH,
LarryB

 

[Mac Attack]

Using a puller is an extra step to go through, but I've removed/replaced mine recently when changing my dry sump oiling system back to a modified OEM oil pump and it wasn't bad.

The ATI seems to work OK. With the dry sump I took the engine up to 9k RPM on almost every drive. Maybe about 10k miles total on it, and let's just say sustained high RPM use. For a 90 degree V6 with such splayed crank journals that we have and a good 550 crank HP, it's doing it's job as I probably would have destroyed some of the bearings by now.

 

[mtung]

I'm on the fence with this as well, if the OEM + shield is a better call than an ATI. Especially with the cost difference and I'm sure a dealership will be hesitant to install it. It seems ATI are technical experts in the field with a customer list that covers pretty much every racing entity and application. I still wonder if that's the right call for a NA stockish street car. I guess this is how I see it, but curious if my assumptions are wrong.

OEM
+Should be OK for 90,000miles 10 years? (coincide with timing belt)
+<$300 +$200 for shield
+HB shield is low cost and should mitigate the failure
-Possible failure which can lead to interference with the timing belt


ATI
+Rebuildable
+No failure mode where it cuts the timing belt
-~2 cost (not including the shield)
-unknown service life

Has anyone had an improvement with the common ~1500-2000rpm vibration with the ATI? That is one part with the stock HB that honestly bothers me. I think it's not torsional, more engine shake but figured I'd ask.

Thanks,
Michael

Also cool cutaway picture of the ATI below!

 

[Mac Attack]

ATI
+Rebuildable
+No failure mode where it cuts the timing belt
-~2 cost (not including the shield)
-unknown service life

If you do some research, you should be able to find these priced just a tad over OEM.

I think mine came from Summit Racing. I've seen them advertised on Amazon too at great prices.

 

[mtung]

If you do some research, you should be able to find these priced just a tad over OEM.

I think mine came from Summit Racing. I've seen them advertised on Amazon too at great prices.

Oh that's a pro-tip right there! Indeed I see a good price on summit!

So question for all the ATI people. How are you preventing the engine from spinning? I know the stock HB has that hex tool with a hole. Is there something similar with the ATI version or are you guys jamming something into the flywheel teeth?

**EDIT nvm found this:
http://www.nsxprime.com/forum/showthread.php/163409-ATI-Damper-puller-installer

 

[Honcho]

Honestly, unless you are racing the car on an oval, or are raising the rev limit, I think the ATI is overkill. The factory pulley + the design of the cam gears is sufficient to deal with any harmonics at the factory rev limit. If you are like Dave and go beyond 8,100 rpm, then this mod makes a lot more sense because the factory parts were not deisgned or tested to work with engine revs beyond the factory spec. In that instance, I would also strongly recommend replacing the factory oil pump gear with a billet unit. If not, then I would just replace your factory pulley every other TB/WP job like Kaz recommends. You would not need the shield if you do that.

 

[BATMANs]

For my engine build I used both the ATI and the shield.

20k miles and no issues.

Spirited street use

 

[BBVNSX]

So question for all the ATI people. How are you preventing the engine from spinning? I know the stock HB has that hex tool with a hole. Is there something similar with the ATI version or are you guys jamming something into the flywheel teeth?

I fabricated a special tool to work as the hex tool, you can see it on the link below, and also the explanation:

http://www.nsxprime.com/forum/showthread.php/170650-BBVNSX-93-EDM-NSX-From-Portugal!?p=1717377&viewfull=1#post1717377

I have the ATI super damper since 2013, no problems, but I Haven't cover more than 10.000 miles.

 

[asylum]

Almost same question for a tracked NSX (almost stock engine) :

- stock + shield
- ATI
- RF Yamamoto lightweight (http://www.rf-yamamoto.com/NSXengine/2.html)

 

[Mac Attack]

The RFY option is a good way to ruin the engine bearings and crankshaft.

On a mostly stock engine I would use the OEM damper.

 

[BBVNSX]

Some good information on this topic here:

http://www.nsxprime.com/forum/showthread.php/183020-Crank-pulley-questions

 

[mtung]

^ Good link BBVNSX! My engine is stock and I plan to keep it that way. I will go with the OEM HB and shield. Although I imagine the ATI works just fine, I know for sure the Honda HB is tuned to mitigate the specific fq.

It's nice that the engineers are now able to let a little bit of this information out.