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

Time to warm up the engine for the compression check.

The old and new spark plugs. Obviously, no corrosion at the insulator on the new one.


Although the replacement schedule for this spark plug is 60K miles, most of the time, you will need to replace them earlier due to the corrosion like this.


You will need to replace them even earlier if you haven’t replaced the IGN coil cover seals especially the one at the rear bank.

Also not good for your IGN coils.

Quite often, I noticed that several wires, looms, etc were trapped around the valve cover area.


On this NSX, the routing of the cable for #3 and #6 IGN coils were wrong.


The one for #3 cyl was trapped under the protector and damaged the sleeve but luckily, no damage to the wire causing instant misfire.


Will be routed properly at the final stage of the service.

In the process of compression check.


This NSX is from the very early model but still reasonably at low mileage.


The result of compression check was similar to what I saw on other C30A engines.

[unit: psi]
Cyl 1: **0, Cyl 2: **6, Cyl 3: **6
Cyl 4: **4, Cyl 5: **7, Cyl 6: **1

The full data will be provided to the owner only.


As seen on many engines, by now, the valve clearance is not matched between each cyl and thus, the data showed some deviation but nothing unusual.


Should get closer each other after my valve clearance service.



Our C30A engine is fairly strong.


I already covered more than 133K miles and still the compression and leak down check showed very healthy data.


From here, just keep removing all the parts to access the TB and WP.


Kaz