New engine project /Mazda MX-5 Miata

NA6CE was launched in 1989 and NA8C in 1995. Almost 20 years passed since the first models have been launched.
The NA models we handle are mostly cars with a mileage over 100.000km. Even models with a mileage over 200.000km are not unusual.
These days many users think about engine overhaul when considering the age and mileage of the vehicle.

These cars’ engine's overhaul is being carried out at Maruha quite frequently. Generally the engine head, engine block, crankshaft, valve are reused. The parts that are exchanged are for example the cam, piston, metal bearing, pumps, timing belt etc.
There are many cases, when simultaneously with the overhaul the users want to tune the car. However, they are worried about the oil consumption, the bad fuel consumption, the engine noise and the money that the O/H and tuning together might cost.

Here we want to introduce our NEW engine setup menu.
From the cam cover to the oil pan, in the new engine supplied by the maker everything is brand new.

We can refresh the engine from another point of view than in the case of O/H that is carried out while considering the abraded and used up parts.
The parts that don’t belong here are the intake and exhaust parts, electrical components, hoses, injector parts.
You can change this engine to a Maruha style engine if you replace the F-cam and the piston.

The new engine’s merits:

  1. No need to worry about the original engine’s condition
    Rather than overhauling the old engine, that’s condition is bad, it’s better to get a new engine. All the parts are new and you can be sure that you can use the new engine safely for a long time.
  2. Shortened setup time

It takes some time to overhaul the original engine. However, if a new engine is being set up, the installation time becomes shorter.
3. A certain estimate can be given to the customer and so there is no need to worry about additional expenses.

NA6CE(B6 engine):

There is no possibility to obtain an engine for NA6CE because its production has been stopped.
We, at Maruha use an NB6C NEW engine, but it cannot be set up without some modificated parts.
The genuine cam for NA6 is being processed, it is HLA adjusted, so the clapping sound can be eliminated.
(Note that the F-cam used in this case is a special item produced for NB6 and it is not being sold as a separate item.)
The original intake manifold and exhaust manifold can be reused.

The NA6CE (NB6 engine) engine’s outlines

Genuine engine + special F-cam&slide cam pulley
The metal head gasket can be added as an option.
You can get more efficiency with normal ECU, Maruha’s ROM tuning or Freedom setup.

NA8C (BP engine):

Gradually it is getting difficult to buy a new engine for NA8C.
Of course, it is possible to install it, but it is also possible to change some parts and install the new tuned engine.
At the setup both NA8 F-cam and NB8 F-cam can be used.
We can use an NA8 genuine piston (83mm) or as an option NB8 (later model) piston (high compression, 83mm)and MAHLE’s piston (forged high compression, 83mm).

The original intake manifold and exhaust manifold can be reused.

NB8C early model (BP engine):

You can obtain a new engine. However, the original one can be set up too.
It can be adjusted to NB8 F-cam.
You can choose an NB8 (later model) piston (high compression, 83mm) or MAHLE’s piston (forged, 83mm).
The original intake manifold and exhaust manifold can be set up.

NB8C later model (BP engine):

New engine can be obtained. However, the original one can be set up too.
It can be adjusted to NB8 F-cam.
As a choice MAHLE’s piston (forged, 83mm) can be set up.
The original intake manifold and exhaust manifold can be installed.

The setup’s options:

  1. genuine engine
  2. +special F-cam&slide cam pulley (except NB pulley)
  3. +B6 high compression piston (78mm) or NB (later model) genuine high compression piston (83mm) for BP.
  4. + MAHLE’s forged piston (83mm) for BP
  5. +H-beam connecting rod or power metal


Maruha Motors Co., Ltd.
Ushizuma 2095-6, Aoi-Ward
421- 2106 Shizuoka city, Shizuoka prefecture
TEL: 0081-54-294-0076
FAX: 0081-54-294-1312