Head bolt and crank main bolt made by ARP

Maruha Motors, Co., Ltd. sells many genuine parts, but mainly engine parts.
Of course we keep gaskets and oil seals and of course Maruha’s original parts too.

This time we would like to introduce you an item, we haven’t had in our lineup until now.
The head bolt and main bolt by APR.

For Miata/MX-5

Restoration of the tensile strength of the bolt

The bolt we use for long years becomes longer and the tension decreases.
A brand-new bolt can revive the tensility.

Stud bolt

ARP bolts are stud bolts.
In the case of the stud bolts a male screw is inserted to both ends.
In the case of the genuine bolt, there is only one screw inserted to one end. In other words, it is a usual bolt.

Where are the stud bolts used for race engine and tuning on the engine head and crankshaft?
Let’s take a closer look at it.

The role of preventing the block’s transformation

The engine block becomes the center, on the upper side there is the engine head, on the lower side the crank shaft and finally the oil pan.
To prevent the deformation, it is essential to use the bolt’s tensile strength.
The bolt is very important, especially when we are putting together a tuned engine or when we are aiming for power-up, higher rpm etc.

Even in the case of Maruha’s power rod ARP’s bolts are being used.
The connecting rod’s bolt is ARP2000.

The efficiency of the ARP bolts

The company ARP is a maker that specializes in different types of bolts.
Everything started in 1968.
Gary Holzapfell founded the company ARP after many of his friends had problems because their race engines blew.
The company improved year by year and became one of the major companies. Their products are being used not only in F1 but also in other racings all over the world.


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
E-mail: info@maruhamotors.co.jp