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

Eng Refresh + LMA, Health Check, etc 12

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Time for the compression check before the Eng Refresh to get the base line reference.

When I removed the IG coil and looked at the state of #3 one, I inspected the coil/plug hole using the fibrescope before removing the spark plug.

After removing the plug, I checked the seating area and also looked inside the cyl and didn't see any issues but with limited space, couldn't maneuver the camera tip well.

The compression data was already sent to the owner.

The figure at #3 cyl was much lower than the rest of the cylinders.
Based on what I saw through the scope, it was not caused by the compression tester tube not seating well and the data is genuine.

This is not the first time I saw this kind of phenomenon in both Japan and UK.
Most of them were caused by the contamination at the valve seating area.
Low annual mileage doesn't help at all.



















As a precaution, carried out the leak down test.

I didn't want removing the valve cover after seeing so much oil seepage and debris before washing the engine so used my super-dooper template for TDC marking.
As expected, #3 cyl showed big and similar leakage figure that I saw on all other engines with the same phenomenon (low compression, big leakage at just one cyl).

Used the stethoscope without the centre rod to listen to the hissing sound of the air leakage from #3 cyl.

It sounded like the hissing was from #2 (exh stage) and #4 (exh/intake stage change over) plug holes.
It may sounded through the oil level pipe (hope not as that will be the ring) but hard to tell as it may resonated while the air moving towards the #2 and #4 valves.

With the fibrescope, all VVIS butterfly screws were still there so not the cause of this.

Once the engine is out of the bay, I'll have better view.



Now in the process of removing all sorts of parts in preparation for taking the eng/gbox out.


More to follow in a few days time.
In the meantime, placing the parts order to Japan.



Kaz









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