Superhead 4V+R Bore & Stroke Up Kit 106cc Monkey Gorilla

【SP武川 01-06-0036 Superhead 4V+R Bore & Stroke Up Kit 106cc Monkey Gorilla Bore Up Engine Parts Takegawa】
■Product Description
This set includes the Superhead 4V+R head kit, cylinder kit, camshaft, and crankshaft kit (with Dyhard α cam chain).
2-point support crankshaft with X-section connecting rod.
Bore diameter 52mm. Stroke volume 50mm. Compression ratio 12.5:1.
Included camshaft: 10/15D

■Detailed Description
●Features of Superhead 4V+R (1 Cam 4 Valves)
Compared to the large-diameter 2-valve Superhead +R manufactured by SP Takegawa, by having two intake valves and two exhaust valves, the valve curtain area can be further expanded, enabling higher intake and exhaust efficiency than large-diameter 2-valve systems.
Furthermore, with the adoption of 4 valves, the head is designed to balance the center plug, valve挟み角 (valve included angle), combustion chamber shape, and port shape, allowing for higher output and achieving the sustained high-rpm output characteristics that are a major feature of the Superhead.
By adopting a 1-cam 4-valve system, it has been possible to achieve as much lightness and compactness as possible, and at the same time, condense the performance as the strongest SOHC head.
●New Shape Superhead 4 Valve +R Body
The rounded cylinder head shape matches the Monkey style well, enhancing the custom image of the vehicle.
Additionally, the barrel-polished die-cast head covers beautifully enhance the cylinder head.
●Valve Features
Valve diameter: Intake: 21.5mm x 2 / Exhaust: 18.5mm x 2
Valve stem shaft diameter: 4.0mm for both intake and exhaust
●Valve Spring
Adopts unequal pitch to prevent surging at high revolutions.
●IN/EX Port Features
The port diameter adopts the optimal port diameter to match SP Takegawa's 3D-shaped manifold.
Furthermore, by installing it simultaneously with the 3D-shaped manifold, a smooth, unobstructed intake effect from the carburetor to the combustion chamber is possible, maximizing the performance of the cylinder head.
●Adoption of Roller Rocker Arm
By adopting a roller rocker arm, the output performance of the Superhead +R is maximized, enabling increased output in the mid-to-high speed range and maintaining output at high RPMs, which is a feature of roller rocker arms.
Roller rocker arms reduce the friction resistance with the camshaft that occurs with slipper-type rocker arms (OEM type parts), and the roller bearings built into the rocker arm smoothly follow the cam profile from low to high revolutions.
●M8 Spark Plug
An M8 spark plug is adopted due to the optimal valve included angle from the 4-valve system and the compact head.
●Hollow Camshaft with Oil Jet (Auto Decompression)
The camshaft employs ball bearing support at both ends, reducing friction resistance in the camshaft journal part.
In addition to the included camshaft, optional camshafts are available, so you can replace them according to your intended use and enjoy the driving performance.
Included camshaft: 10/15D
●Auto Decompression Mechanism
Reduces the force of the kick start and the load on the transmission when starting the engine, allowing for smooth engine starts even with large displacements.
●H Cylinder Bore Diameter 52mm
Adopts an aluminum steel sleeve cylinder.
The cylinder is equipped with a temperature sensor mounting part as standard.
You can measure the cylinder temperature by purchasing an SP Takegawa thermometer-integrated meter or thermometer.
For 106cc H cylinder: M5 temperature sensor
●Piston
Adopts a cast piston.
●Adoption of X-section Connecting Rod
Machined from forged material, adopts an X-section shape.
Ensures sufficient strength while reducing weight, and significantly improves diffusion of buckling stress and torsional rigidity.
Surface is shot-finished.
●Strengthening of Journal Section
Adopts special bearings with an enlarged inner diameter of the crankshaft journal bearings.
This makes it possible to increase the shaft diameter from 20mm to 22mm in the journal section, where stress concentrates on the crankshaft, thereby strengthening the shaft.

■Compatible Models
HONDA
12V Monkey Gorilla (Z50J-2000001～)(AB27-1000001～1899999)

■Notes
※The image is for illustration purposes only. Includes products with different sizes and colors.
※Product design and specifications are subject to change without notice. Please understand.
※This product is made-to-order, so cancellations after ordering are not possible.
※This product is made-to-order, so delivery may take some time. Also, please note that the manufacturer may discontinue the product or change specifications without prior notice. Thank you for your understanding.