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

Cooling Sys, ABS Upgrade, etc 12

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The owner told me that about 10 years ago, he experienced VVIS butterfly screw issue and unfortunately,
the backed out screw was swallowed into the engine causing bent valve.

I don't know how many valves were damaged, which cyl was damaged or any other issues but at this point,
I had no other option but to at least remove the valve covers because there were suspicion on the cam timing and the valve clearance adjustment.



Very interesting result.



First, I noticed that the all 4 cam shafts were aligned properly (the white markings on the cam pulleys were placed by me on this occasion to show the timing clearly
for the owner. They were not there when removed the valve covers) but it was very likely that TB tension was very loose as
I know how each markings would line up when properly tensioned.


I feel very sad for the owner but I'm afraid, the crank shaft is not set properly when the TB was installed and thus,
at each cyl, whenever it should be at TDC, the piston was still on the way to TDC.


However, although at this point I wrote that comment in the photo, there was another catch!


Later, I had a quick look at inside the cyl using the bore scope and that revealed that the piston was in fact already past the TDC
despite the marking on the crank pulley was still showing that it was before TDC (as in the above photo....).



Anyway, while the cam shaft timings were correct, the synchronisation between the cyl head valve train and the crank (piston) was wrong.

There is another major issue but I'll touch on this later.....







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