View RSS Feed

Today at Atelier Kaz - Private NSX Enthusiast, ex-Honda R&D engineer with F1, Indy/CART background

ABS Upgrade, Oil Cooler, etc 01

Rate this Entry










Started to work on another NSX from last week.

The service menu is to carry out Health Check combined with Annual service, ABS Upgrade, Oil Cooler replacement, etc.


As always, started with the general check-up in preparation for the Test driving session before changing anything to understand the existing status.

While looking at the crank pulley, noticed strange offset.

No damages to the TB lower cover (yet) so decided to start the engine.
















And the confirmation of the crank pulley failure.






















Not sure exactly when it started but the weight was still held in place and couldn't detach it even using the pry bar.




















As I normally keep at least one MT spec crank pulley at my place, replaced with new one.








From the service history, it was replaced by someone 5 years ago and only covered about 6,000miles during that period.

The owner mentioned that he only had one track day session.

I know another owner with crank pulley failing at very low mileage/age but had a few track day sessions.


On the other hand, there are many owners driving with old crank pulley with many miles without any issues.

For example, mine is 6 years old and covered 23,000miles and spirited driving but no track days.

I know this failure is heavily related to the sudden continuous acceleration and deceleration so in Japan,
owners who take their NSX on track always keep eye on the pulley and replace it at much earlier stage than
the owners who drive their NSX on street driving condition only.


Personally, I'll only approve the pulley shield design that won't utilise the TB lower cover 10mm bolts.

Once the TB lower cover and the surrounding gasket were heat cycled and took set, you don't want relaxing them.





Any way, glad that we managed to spot it in time before killing the TB resulting in bent valves.











Comments

  1. NSXGB's Avatar
    Very lucky owner.

    Is there a crank pulley shield on the market that does not utilise the TB bolts?
  2. Kaz-kzukNA1's Avatar







    As I like people at T3TEC in Japan, my view is biased but with this one, I have been saying the same thing for years now even before the T3TEC was established.

    I'm happy that they share the same view.

    The only shield that I will approve the design…..

















    Heated up the crank pulley and on purposely separated the counter weight.

    Then, re-installed the on purposely broken crank pulley on the engine and tested the proto-type shield.

    Well protected and the noise generated will warn the driver.

    The markings are the result of the weight scratching against the sheild.




    Kaz

    [All photos courtesy of Mr Toyoizumi at T3TEC Japan.]
  3. solidol's Avatar
    Kaz, do you have anyone local running ATI Super Dampener?
  4. ozon02's Avatar
    Hi Kaz,
    and what do you think about it: ask for an opinion 軽量クランクプーリーキット - Light weight pulley kit

    from
    http://www.rf-yamamoto.com/NSXengine/2.html

    Regards
    Mario
  5. solidol's Avatar
    Quote Originally Posted by ozon02
    Hi Kaz,
    and what do you think about it: ask for an opinion 軽量クランクプーリーキット - Light weight pulley kit

    from
    http://www.rf-yamamoto.com/NSXengine/2.html

    Regards
    Mario
    Mario, Kaz may have different opinion but I would advise against non dampered pulleys unless it's blueprinted engine with near perfect balance. C series needs dampener like OEM or ATI Super Dampener to calm down all the harmonics. I would also argue that if one puts billet pulley on and uses NSX as a street vehicle more than on the track with sitting on higher rpm most of the time it would stress crankshaft mains to the eventual failure.

    In for what Kaz has to say about it.
  6. NZNick's Avatar
    NSXGB - https://www.nsxnet.com/parts_detail.php?pid=8650 - cost in Japan is 120 GBP
  7. NSXGB's Avatar
    Thank you Nick.
  8. Kaz-kzukNA1's Avatar
    I think I got the same/similar question on here or on Prime but personally, I won't use aftermarket pulley especially on NSX engine.

    ATI pulley is being used by my local race team in their monster drag racing machine so must be of a good product but I don't know how it was tested on the dyno using the NSX engine or the simulated model.

    The one from RF-Yamamoto was introduced on the market ages ago.
    At that time, the developer advertised it on one of the most famous NSX Forum in Japan but didn't go down well.

    For our NSX engine, there is a reason for why the crank pulley is so heavy.
    At certain rpm range, there is a resonance frequency that if continuously kept running at this specific range, it could shorten the life of the TB.
    The OEM crank pulley is there to shift this resonance order out of the designed usable engine rpm.
    Almost impossible to keep running the engine continuously in this rpm range even on track but none-the-less, if you run the engine on the dyno, you can detect it.

    Very little risk but I don't see the reason to go for the aftermarket one with unknown test procedures.

    In Japan, the general consensus now-a-days is to replace the OEM one at every TB service for street driving condition NSX and at much earlier stage or install the shield if taking one's NSX on track.


    Kaz

    Updated 04-08-2018 at 10:52 AM by Kaz-kzukNA1 (typo, extra info)