ATI lists three different damper for the L series and Summit sells all three.  The bolt is always sold separate.  ?

ATI Dampers for Datsun/Nissan

Call Eiji.....he’ll be happy to help you out.....tell him I told you to call and you are trying to put a bet down (on my car) to win our Dinwiddie race this Fall! Seriously....Eiji will be happy to give you the right info.

Cool, thanks.  I always read your posts about Eiji and his great work, but never realized until now, that he is Datsun Spirit.  Duh...

https://datsunspirit.com/shop/ati-harmonic-damper-kit/

IIRC the Kameari bolt isn't quite long enough.

Regarding the underdrive on the alternator, at race speed it should be fine, a friend did some calcs on a road use engine, he said at idle and to 1500rpm is it wasn't enough.  Anyway, ended up changing the alternator pully to a smaller one.  Job fixed.

I bought two ATI's that did not fit.  I would not touch them. Quality is not good.

 

Jeff Priddy, a Datsun super user, has done long term empirical development of an L series turbo for very high and reliable HP. He worked closely with BHJ to develop an exclusive damper for his needs.  They now sell it:

http://harmonicdampers.com/index.php?main_page=index&cPath=74_10

 

http://forums.hybridz.org/topic/58936-standard-bhj-vs-rebello-bhj-damper/

 

Jeff's work is worth looking up on the net.

: http://www.angelfire.com/extreme/280zxt/

1 hour ago, 240260280 said:

I bought two ATI's that did not fit.  I would not touch them. Quality is not good.

 

Jeff Priddy, a Datsun super user, has done long term empirical development of an L series turbo for very high and reliable HP. He worked closely with BHJ to develop an exclusive damper for his needs.  They now sell it:

http://harmonicdampers.com/index.php?main_page=index&cPath=74_10

 

http://forums.hybridz.org/topic/58936-standard-bhj-vs-rebello-bhj-damper/

 

Jeff's work is worth looking up on the net.

: http://www.angelfire.com/extreme/280zxt/

I think thats the only negative review of an ATI damper?

Great info, thanks 240260280.  Where is everybody sourcing their bolts?  I see lots of talk about bolts and lengths, but few specifics and very little on sourcing.  The NISMO bolt is NLA and each brand of damper appears to need a different bolt length to maximize the thread engagement.  Is the KA bolt the OE one, or something else?  I appoligize for sounding dumb, but the more research I do, the more questions I have...

As far as installation goes, green Loctite on the bore, red Loctite on the threads and then what torque on the bolt?  "How To Modify..." book states to use the manufacturer's recommendation for non-stock bolts.  

I've been endurance racing with various L Series engines for years and this is my first crank bolt issue.  I plan to learn and eliminate this failure method in the future.

Maybe it's because I've never had a damper come loose, but I don't think I would use red Loctite on those threads. I'm thinking thread lock blue would be enough?

And when you said green on the bore... Are you talking about their sleeve retainer? If so, I wouldn't do that either. That's like belt, and suspenders. And nails, and screws, and bungee cords, and duct tape. If you use sleeve retainer on the bore and red on the threads, it's gonna take a lot of torch to get that stuff apart if you ever need to.

Of course, all of my opinion might change if I ever had one come loose like you did, but that really sounds like a bit much.  YMMV

Same here Captain.  I never gave it a second thought until I DNF'd a race, missed another race and caused hundreds to thousands in damage.  After spending a lot of time on various sites including reading the links 240260280 posted, as well as rereading Frank Honsowetz's "How To Modify Your Nissan/Datsun OHC Engine" book, it sounds like the green and red Loctite applications have been in use for decades.  Since the internet began, I've learned who in the Z community to trust and the common theme here is that they all agree on a quality damper, high strength bolt/washer in the right length and Loctite on the shaft and threads.  I never had any idea that the bolts ever came loose, but apparently, it's super common.  I guess I should have been aware and built my engine right in the first place.

I understand completely, and I'm not telling you not to. Just bringing it up. Do whatever you need to do to finish the race!

On a related note... I wonder how much heat the damper rubber can deal with. According to Loctite:
The red thread lock "For removal, it may require localized heat (>550°F/260°C), hand tools, and disassembly while hot"

And you've got quite a lot of thermal mass there. So hopefully once it's on, you won't have to ever worry about damaging the damper rubber because you just won't have to mess with it!  

And I hope I never have the problem you did!