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

MX5 Engine Refresh 01

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As this is NSX site, I won’t go too much in detail for non-NSX related service.

I’m just posting this for the owners waiting for my service so that
they have some idea on what is happening at my place at the moment.


Also, there are several topics that can be shared with NSX so
I’ll touch on these later.

For example, the internal engine parts were very clean even after 19 years with
just over 64K miles but the WP bearing was not smooth despite it was replaced
during the last TB/WP service and the coolant being replaced every 2 – 5 years.

Thus, my recommendation to replace WP at every TB service on our NSX regardless
of mileage covered.







There was some oil seepage from the valve cover gasket area but
not too bad.

Still, washed it down before opening the cover.








TB, cam pulleys, WP, etc removed.









About to take out the cam shafts.

Very clean engine even after 19 years.

It covered only 64K miles during this period so it is at low annual mileage but
I kept replacing the engine oil regularly and once again,
this photo proves the importance of doing so on low annual mileage car
even on a different engine.

Some of the NSX engines were much dirty compared to this one even
they were newer and at far less mileage.


Like the time consuming valve clearance adjusting process on our NSX,
the Hydraulic Lash Adjuster (HLA) used on this MX5 takes ages to overhaul....

16 of them in total......


Even replacing the engine oil regularly, the oil doesn’t flow freely
(should not as it relies on the oil trapped inside there to maintain
good valve clearance) inside this HLA so by the time when you
carry out the TB/WP service, it will be pretty much black oil inside.




Can’t wait to clean the internal engine parts again….

More to follow later.

Kaz


Updated 28-09-2012 at 01:26 PM by Kaz-kzukNA1

Tags: hla, mx5 Add / Edit Tags
Categories
Engine Refresh - Other Models

Comments

  1. greenberet's Avatar
    Dear Kaz,

    The adjustable front strut tower brace in your MX-5 looks good. Is that an OEM part in certain NA Eunos Roadsters? Have you tried driving with and without it on public roads? If so, did you notice a difference in how the car feels?
  2. Kaz-kzukNA1's Avatar
    Hi, greenberet.

    My MX5 is Eunos Roadstar (JDM) and it’s 1993 1.8L 5MT V-Special II so it has different interior and exterior parts compared to the standard models.
    I think 1.8L engine was only available in 94 for UK models.

    The front tower bar is Mazda OEM one.
    It was standard equipment on S Special model but it was also available as an option for other models so I just included it.

    Compared to our NSX, MX5 is designed with the affordable open top enjoyment for everyone in mind.
    Therefore, with the targeted cost, everything around the interior/exterior including the chassis stiffness are just enough for normal driving conditions.

    You can actually see the chassis twisting if you try to lift up just one corner so the chassis stiffness is not great.

    The effect of tower bar is OK level.
    On MX5, the engine height is fairly high while the damper tower is bit low so the tower bar design has to go up a lot first before connecting to the other end and with just two nuts to hold the bracket to the mounting place, not that ideal.

    Still, addition to the changes in resonance frequency, you can actually feel the difference in handling.
    If you have ever seen the NSX and MX5 frame repair process, the damper tower mounting point on MX5 is not stiff and nowhere near to the level of NSX so anything that can stiffen that area will help.

    I don’t track this MX5 so even the frame twists, that’s fine with me.
    I don’t have NSX-T but MX5 is fun to drive although it’s mainly used by my boss......

    Kaz

  3. greenberet's Avatar
    Dear Kaz,

    Thanks for your insights. In the NSX, the front shock towers are already kind of connected by that “pan” at the base of the windshield. Do you think that “pan” is stable enough that an additional stock tower brace would not impact the torsional rigidity and resonant frequency? I can imagine you wouldn’t want to add a front shock tower brace to your NSX, but do you think it would do anything to the chassis other than add weight?