Maruha motors

BP86.0mm MAHLE Piston for NA8/NB8

The actual numbers of NA/NB cars are getting smaller and smaller recently (as of November, 2022).
Because the genuine parts are also remarkably discontinued, how to perform maintenance for your own lovely car is a big issue.
Since the prices of used parts have skyrocketed in the parts market, the traders are indeed smart in dealing.

Especially many people take interest in engines.
How should I perform engine overhaul? Like this message is coming to MARUHA every day.

Not only asking for basic overhaul, but a lot of turning up engine for power increasing is also requested.

In some cases, after overhauling and enlarging engine block were already done, one more overhauling is requested again.
Many people have experiences in damage of engines during racing and track.

The size of genuine piston stock is 83.00mm.
There are many kinds of oversized pistons in the market. MARUHA special largest forged piston made by MAHLE was 85.50mm.

The cast iron block has still some extra space.

Then Maruha has decided to try to make the piston with 86.00mm as a new item to have a chance of reusing a block.

In case of the genuine crank or MARUHA crank (stroke 85mm) as replacement for the genuine one (86mm x 85mm).

Displacement 1974cc
Compression ratio 10.6(genuine head combustion chamber, gasket 86 x 1.0mm)

In case of purpose for increasing displacement:

Special clearance collar
Special clearance collar
Special clearance collar

Used with MARUHA87mm Stroker: Displacement 2020cc (86φ x 87mm)
Compression ratio 11.1 (genuine head combustion chamber, gasket 86 x 1.8mm)

Used with MARUHA87mm Stroker: Displacement 2067cc (86φ x 89mm)
Compression ratio 11.4 (genuine head combustion chamber, gasket 86 x 1.8mm)

(Notice) For adjusting surface grinding amount and compression ratio, 86mm x 2.0mm gasket can be used.

Increasing from 1839cc as genuine to 2067cc as maximum at a time can be possible.

Making an engine with good torque and power can be expected enough.


Application: NA8/NB8

Piston diameter: 86.00mm

Compression height: the same as genuine

Pin diameter: the same as genuine 20mm

Dome capacity: +8cc

genuine connecting rod is usable / Using MARUHA power rod together is recommended.

Piston weight:324g(average)


Special clearance collar
Special clearance collar
Special clearance collar
Special clearance collar
Mahle Custom made PistonFor BP engine 86.0mm
Mahle パワーピストン MAHLE SPECIAL 86.0mm #2618(2023年11月〜)
code:mar22050700 For BP

If you have any questions, please feel free to contact us.

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