Today at Atelier Kaz - ex-Honda R&D, F1, Indy/CART engineer

Very impressed with the state of the valve covers and
the cleanness of the internal engine parts
considering its hign mileage.

The owner is happy for me to mention that
his engine has covered more than 100K miles.



The cleanness is far better than most of the
low annual mileage engines.

Almost no sticky gunk behind the valve cover
even at the front bank and
the cyl head, cam holders, rocker arms, etc were
covered in light brown colour but not like the
dark one that you would see on
many garage queen NSX engines.



This proves that the car was used regularly with lots of
long distance cruising/accerelation mode and most importantly,
the eng oil was replaced regularly.



Eng oil is a fluid bearing as well as the cleaner.
So, you tend to find more unusual engine issues on
low annual mileage NSX than the ones used regularly.




Even the owner(s) took good care of this engine for
more than 100K miles, it’s a shame that the people worked
on it didn’t pay the same level of attention.

The valve clearance was awful.

Even at the same cyl, one side of the exh/inlet clearance was
too wide whereas the other side was way too tight.
And despite the #1 and #4 cyl showing reasonable compression,
the issue with the clearance was at all six cyl.







As mentioned in the previous post, the rubber seal at the
valve covers were not installed properly.

In fact, at the rear bank, the dislocated rubber seal was
bouncing against the TB and cam pulley at high speed that
it left lots of rubber dust and even circular marking inside there.

A piece of rubber fell out when I removed the TB rear cover so
that would be the left over of the seal.
It was just a small piece so majority of the missing rubber was
turned into the black dust.












When inspected the cam timing and TB tension,
the timing itself was OK but the belt tension was
way too loose.

Even holding the crank pulley under tension,
you can see that the TB is so relaxed in the 2nd photo above.











One of the TB lower cover bolt was cross threaded
so had to re-thread it.










As seen on many NSX, the potting of the CRK/CYL sensor
melted and running down the back plate.

Will clean it as much as possible and the sensor will be
replaced considering the mileage although it will be fine
for a while even after loosing its potting completely.



Now that the initial inspection is done,
I’ll back off the valve clearance adjuster and
start removing the internal engine parts so that
I can wash them separately.

More washing up to do........



This week, I can only work on this engine until
tomorrow and then I must focus on another projects
for the rest of the week so the update of the blog will
stop for a while.

More to follow later.

Kaz