I’m glad I can now access this site again. For some reason, I couldn’t access NSXCB site yesterday and couldn't reply PM or update the thread.

Hi, goldnsx.
I’ll post some photos later when I write up the timing belt (TB) service but the leakage was caused by the cyl head/valve cover gasket not being installed properly during the previous service. The edge of the rubber gasket at both Front and Rear banks were partially caught between the head cover and cylinder head at the exh port side resulting in poor sealing.

Some of the leaked oil ran down along the rubber seals of front and rear TB mid covers and then along the seal of TB lower cover and finally dripped down to the recess at the bottom of crankshaft/TB drive pulley.

It was not from the crankshaft oil seal that is pushed into the oil pump.

Even with this huge amount of oil leakage, the TB was well protected and no oil at all on the old TB itself. The seals on the mid/lower cover done the great job.

Regarding the famous crank pulley shield, I saw the actual product several times in the past and it was well made parts. I believe it is quite popular on the NSX Prime.

However, I just simply don’t have enough experience and endurance data to fit it on someone’s NSX before testing it on my NSX.

In Japan, among the owners using the NSX specialists, I have never seen this shield on their NSX. Addition to the lack of experience and endurance data, we have differnt driving condition and different TB service interval compared to Europe, US, etc so probably this is the reason for not using the shield. On top of this, it is widely known to the NSX specialists that we MUST replace the crank pulley regularly at least at the time of TB service or even more frequently if the owner tracks his/her NSX or using sharp acclamation/deceleration rpm. Still, I heard the disaster story a few times from the owners who didn't replace their crank pulley....

 So, it’s up to the owner to make decision and while the product and idea is great, I normally don’t use it.

As a side note, I saw lots of discussion on the reason for the weight on the crank pulley in other car forums. While most of the opinions are correct for other models, for NSX, it is for the protection of timing belt itself. This is already mentioned somewhere on the Japanese car forum so I'm comfortable to refere it without causing IP issues.

At a certain rpm, there is a resonance point where it is not safe for the TB to be held at. On the street driving, it is almost impossible to keep the engine at this rpm but as a production car manufacture, it is not acceptable and thus, had to use the weight to shift the resonance point out of the usable engine rpm range.
So, even with the shield, it is not safe from the timing belt point of view even without any damages to the lower cover. The vibration frequency is completely different from the normal condition when the weight was partially dislocated and spinning like on and off at the pulley.

Regards,
Kaz