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

Spent long time cleaning the engine bay while the engine was out.

It became clear that most of the corrosion protection oil was already
burnt into the paint surface and would not come off without using
strong chemical or polish.
Decided to clean as much as possible only with the safe method.


It was the same on the engine, Gbox and the surrounding area.

The brown/yellow burnt oil won’t come off even using the
cleaner solution under high pressure.

I even spent some time using the brush to clean the engine with no luck.
So, just cleaned as much as possible using the same method for everyone.
















Started to open the engine and immediately noticed very loose timing belt and
wrong timing at the rear bank exhaust cam.

Someone even put some paint on the arrow at the oil pump so this person knew
what he was doing but still managed to make mistake.

Originally Posted by kaz-kzukna1

The full data has been emailed to the owner.
[psi]
#1: **4, #2: **8, #3: **3, #4: **0, #5: **5, #6: **8


Very strong compression that you will expect from such a low mileage engine.
Having said this, bit surprised with the level of deviation between
the cylinders although it was well within the spec.

May be someone adjusted it in the past even at this low mileage???

Hope I can get them close each other by the engine refresh service.

Now I understood why I made this comment in the
previous post, Eng Refresh Stage 1 – 01.


The idle rpm was fairly stable with no distinctive fluctuation and
the owner mentioned hesitation at one time while driving although it
disappeared after driving for a while.

I also noticed minor hesitation but I told the owner that it would be
probably the unknown age of the fuel inside the tank.

To be honest, I couldn’t test drive the car properly under wet condition with
these very-very old tyres and brake imbalance so something to consider in the future.
Learnt something new again today....


Any way, the wrong timing was caused by either the wrong setup during
the last TB service or the timing was set properly but not the TB tension and
allowed the TB to jump one tooth under reverse torque such as
stalling the engine with CL engaged or spun off on track.


This is not the first time I saw this issue on NSX engine.
In Japan, I already saw/heard the same issue on many engines after TB service
even carried out by the Honda garage.

I'm also a humanbeing so I do make mistake but not on the valve timing and
the TB tension.

If you have been following my blog, you probably have seen hundreds time that
I use the word such as ‘checked, checked and checked’ the valve timing and also
the belt tension because of the very reason.


It is quite difficult to install the TB while keeping the engine inside the bay especially
at the rear bank.

So many people relies on the hole on the cam holder and the cam shaft for the
valve timing and even the workshop manual states like that but not quite correct
especially on the early model NSX.
You can’t even insert the locking pin at the exhaust side of the front bank on
some of the engine.



You should not rely on these holes for the valve timing.



Instead, you must look at the marking on each cam pulleys and
follow the marking towards the back of the gear tooth where it meets the
engraved marking on the cover plate.

You will need to use the mirror for this if your engine is inside the bay.

Also, there are another set of markings on the other side of the
cam pulleys that you can see from the inside of the engine
(from cam holder side) that shall line up at the top edge of the cover plate.



These are the markings to be used for checking the valve timing and
not the holes on the holder plate and the cam shaft.


Any way, just one tooth off on the valve timing won’t cause any
mechanical issues and as I didn’t see out of range compression data on
any of the cylinders, I’m quite comfortable with the mechanical side although
I may carry out the leak down test as well.