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

Eng Refresh 13

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4 Comments
by
Kaz-kzukNA1
, 24-04-2014 at 01:03 PM (6732 Views)







Front head removed and even before lifting it, I knew something was not right
as there were several noticeable markings on the head bolts.







By the way, the V-bank was cleaned to this level. Before/after.







While the level of carbon was much better than the rear bank, the colour of
#4 exh valves and part of #6 were very different from others.
Also, there were unusual deposit left on the #4 spark plug.

By the way, #2 spark plug showed very white deposit and #6 one just
smelt awful.




While the gasket shape could be deformed while I was lifting the head,
clearly there is rusty marking behind.
In fact, it's the section below that the coolant escaped.








And this is what I found after peeling off the gasket.
Several rusty spots observed but glad that the cyl wall were fine with
no abnormal markings.
As always, cross-hatching was still there even after so many miles.
Categories
Eng Refresh Stage 1 + LMA

Comments

  1. britlude's Avatar
    what coolant anti-freeze did the car have?

    before i knew better i had pink antifreeze in the hotrod, later finding out the hard way that it has organic acids in it, which corroded it's way through my composite head gasket!!

    i only ask as the hotrod head gasket looked surprisingly similar when it failed!
  2. nsx60's Avatar
    What anitfreeze do you now recommend ?
  3. Kaz-kzukNA1's Avatar
    Quote Originally Posted by britlude
    what coolant anti-freeze did the car have? .......................................
    You can probably just able to see the hint of green colour coolant left inside the cyl jacket in the last photo above.
    Very likely to be the ones used by the Honda garage and many other places in the past.

    Yes, I heard about the OAT coolant affecting several models through some of the Japanese car manufactures TSB.
    Honda doesn’t use it any way.

    Kaz

  4. Kaz-kzukNA1's Avatar
    Quote Originally Posted by nsx60
    What anitfreeze do you now recommend ?
    My recommendation is still the same.
    Honda Type 2 coolant or any equivalent ones although I don’t see much point in not using Type 2 when it is already being tested on Honda engines.

    For the clarification, the rust in the photo is not the result of the normal coolant usage even it was the green old spec one.
    The spot lifted section trapped the moisture and resulted in rust.
    Under normal usage, this won’t happen.

    If you take your NSX on track with OEM radiator, then it is probably better to reduce the mixture level to 30%+ for better cooling efficiency and replace it before winter if you live in freezing cold area.
    Even you live in milder condition, you must replace it at shorter interval (every 2 years) if you changed the concentration level and not the normal maintenance cycle of every 5 years for Type 2 coolant.
    It is premixed at 50% which is very rich/conc to cover all sorts of weather conditions as well as for the protection against corrosion.

    Kaz