Carbon timing cover

Cam cover (brand-new part base) & timing cover set

Cam cover (cutting & paint) brand-new part base

Cam cover (paint only) brand-new part base

Timing Cover

It is possible to cut out the top of the cam cover of NA6 and NA8.
As soon as the engine starts, the cam gears start making a horrible noise quite unfavorable to a mechanic.

In addition, in case the stock cam gears are uninstalled and taken out, it is possible to modify the valve timing easily in the process of installation of the variable cam gears.

With the help of the timing belt, the revolution of the crankshaft is transferred to the camshaft.
Therefore, not only the internal parts of the engine, but any kind of hindrance to the timing belt or the cam gear might cause big trouble.
Hence, the manufacturers always make sure that the timing belt is covered completely.
Maruha's timing belt cover is manufactured very uniquely.
The timing belt cover is easily fixed after cutting out the top portion of the cam cover giving it a very sleek and cool look.
The bolt hole of the stock cover is used in the process of fixing the cover, making it less time consuming and allowing an easy installation.
The manufacturing material is specifically Real Carbon. (Note: It is not dry carbon.)

(As shown in the picture, the red circled parts are the genuine bolt holes utilized to make the installation simple and easy).
Not only do they appear cool but they also play a very important role by helping in the rotation of the timing belt and the cam gears.

As you can see in the picture above, the internal design is refined clearly to guarantee clearance between internal rotations.
Also pay attention to the installation of the bolt.

The carbon cover is fixed by the bolt but the stress of the bolt is caught by the cover, preventing damage.
The fact of dropping some fragments in the timing belt cannot be avoided. Therefore, we have designed it exclusively by using aluminum collars.
On the other hand, the use of the rubber O-ring along with the bolt fixes it certainly and stops vibration.

Cutting of the Cam Cover Top

As shown in the picture below, the red painted surface and the non painted surface are originally one identical part .
The bulged out side and the covering side share the same wall.
They are both cut and divided into two parts leaving a thickness of 0.1mm from the original thickness of 2 mm.
This means that the bulged out part is cut out.

(As in the picture white circular section which is originally the same wall, is cut divided)

This kind of cut processing is called wire cutting.
We use the exclusive cam cover jig of the Roadster(Miata) in Maruha.
After setting it in the tank with full water, cutting process is carried out by passing electric current through a very thin wire.
This cuts the cover top accurately and also gives a neat finish. This enables us to install the timing cover easily later.
In other words, in order to install the timing cover it is necessary to cut out the cam cover accurately.
After cutting, the rugged surface is polished with the file and paper and then painted.

Raw paint of the Cam Cover

After cutting out the cover, the soiling and oil is removed from the surface with a steam washer.
It is then sand blasted and rewashed with steam. The foundation to paint is applied followed by several application of raw paint.
The blast processes the foundation to paint securely and makes the close adhesion of the paint better.
In the intermediate process holograph can be used. Finishing is done by glossing. Glossing makes the surface hard and resistant to heat.

Cam cover exclusive washer

The surface paint can be damaged easily by the friction of the volts and the cam cover surface.
Exclusive cam cover washers are used in order to prevent the damage caused by friction.


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