Superhead 4V+R complete engine 181cc (WET)

* This product will be made after an order, We will notice currect shipping time after we recieve an order.

* This item can not be cancelled, returned nor exchange after placing an order.

[Super head 4v+r (1 cam, 4 valves)]
Two intake / exhaust valves are used each to increase the valve curtain area and achieve high intake / exhaust efficiency.
The original head shape was designed to balance the center plug, valve pinching angle, combustion chamber shape, and port shape to achieve a higher output than the stock head.
The combustion chamber is finished with high accuracy by NC machining.
The surface of the Superhead 4V+R cylinder head is painted black.

・Valve Diameter IN: 25mm x 2 / EX: 21.5mm x 2 Valve Stem Shaft Diameter: 4. 5mm for both IN and EX
The use of unequal pitch valve springs prevents surging at high RPM.

・Forged aluminum roller rocker arms are used.
The frictional resistance with the camshaft is reduced, and smooth operation is realized.

・Auto decompression camshafts (standard 10 / 10D camshafts)
Smooth engine starting is possible without placing a burden on the starter.

・Optional parts: 15 / 15D Camshaft
It improves the output performance in the mid to high RPM range.

Since the inspection breather cover is included, you can release the internal pressure of the engine by purchasing the oil catch tank kit separately.
Inspection breather cover, inspection cover, and L. cylinder head side covers are all die-cast aluminum with barrel polished finish

[cylinder, piston, reinforced crankshaft, big throttle body]
■Cylinder
The cylinder is an all aluminum ceramic cylinder with excellent durability, airtightness and heat dissipation.
Black painted surface.
An oil outlet is provided so that oil can be taken out to the oil cooler.
In the case of the complete engine, this oil outlet is used to connect the special clutch cover to the cylinder with the oil line hose.
This changes the oil line flowing to the cylinder head side to via the oil element.

■High compression piston (compression ratio 12.5)1 is adopted)
Pistons designed for high performance and durability.The piston top is NC machined for high precision.

■Reinforced crankshaft (X-shaped connecting rods)
The X-shaped connecting rod is used to achieve high strength and light weight.
This makes the crankshaft much stronger than the stock crankshaft and is suitable for high displacement complete engines.
It is lightweight and strong enough, and its buckling stress diffusion and torsional rigidity are greatly improved.
Surface shot finish.
Die Hard Alpha Cam Chain 88L adopted

■Big Throttle Body Kit
You can get the best performance from the super head and enjoy the engine characteristic without stress to the high RPM range.Bore Diameter: Φ34
Air filter kit (for big throttle body): By increasing the surface area, high inhalation efficiency can be obtained.With blow-by union
With the installation of the big throttle body, it is necessary to change to the large capacity injector that comes with the complete engine.

A shroud bracket is also included.
SP Takegawa's oil cooler can be installed on the shroud bracket.

[Special clutch TYPE-R (WET) wet clutch / TAF 5-speed cross transmission]
Equipped with a special clutch kit that uses a high end clutch unit and a special clutch cover with excellent functionality.

■Special Clutch Cover Details
Die-cast aluminum R. Crankcase cover is adopted.
Black painted surface.
The clutch part has a separate chamber structure, and in the case of a wet clutch, the engine oil and the clutch oil can be separated.(Brand name, specification, etc.)
For the complete engine, the clutch cover is only available as a wire type.
The wire type uses a forged aluminum clutch cover and a rack and pinion system that is known for its light and smooth operation.
The surface of the forged aluminum clutch cover has been shot blasted.

■Built-in oil element
Filters out sludge and metal wear particles in the oil.
Oil element is a cartridge type paper type

■Oil-through Nut Significant weight reduction is possible!!!
Centrifugal oil filter approx.1069g → Oil through nut approx.123g
You can remove the stock centrifugal oil filter which puts a burden on the crankshaft by replacing it with the attached oil through nut.
This allows the crankshaft weight to be reduced from approximately 1069g to approximately 123g, resulting in a significant weight reduction.
Also, the engine response will be improved by reducing the load on the crankshaft.

■Oil level check window and large filler cap adopted

■Oil outlet The oil can be taken out from the cover body directly to the oil cooler.
SP Takekawa has the oil cooler kit for the vehicle with special clutch cover.

■Patented structure: Thermostat mounting and oil line structure
Overcooling can be prevented by installing optional thermostat unit when SP Takegawa's oil cooler kit (with the specification that oil is taken out from the clutch cover) is installed.
*Must be installed with SP Takegawa oil cooler kit.

■New mechanism The oil line that flows to the cylinder head side is changed to go through the oil element
The oil line hose on the complete engine allows the oil flowing to the head side to pass through the oil element.
This prevents engine damage caused by oil sludge.

■Special Clutch Inner Kit TYPE-R Details
6-disc (without slipper clutch) specification
By reducing the diameter of the rotating parts such as the clutch outer, the loss of horsepower due to oil diffusion is reduced, the response is further improved, and the rotating mass weight is reduced, so the engine power can be transmitted without waste.
Six-disc design with five KV friction discs and one judder friction disc.
This reduces judder when starting and at the same time increases the clutch capacity to accommodate high power engines.
For the complete engine, the clutch construction is only available without slipper clutch.
Primary driven gear with built-in damper
Built-in rubber damper to reduce shock to gears when clutch is engaged.
Clutch Spring
Excellent fatigue resistance and stable clutch feel.

■TAF 5 Speed Cross Transmission Kit
(1st gear: 2.333 2-speed: 1.684 3-speed: 1.272 4-speed: 1.040 5-speed: 0.923)
By installing TAF 5 speed cross transmission, you can accelerate smoothly while keeping the power band of the engine rpm.
It can be used with SP Takegawa's big bore kit without changing the torque-full output characteristics.
This product secures the tooth width by shortening the travel of each gear, and improves durability.

[Other internally used parts]
■Crankshaft support adapter (patented structure)
The crankshaft journal has been changed from a 3-point support to a 4-point support to reduce crankshaft shake at high rpm and increase crankshaft durability.

■Super Oil Pump
In order to find the optimum oil discharge rate, an increase of approx. 35% from the stock rate is adopted.
The strength of the oil pump body has been increased by increasing the thickness of the plate and the number of bolts that connect the body and plate.

■Super Cam Chain Tensioner
It follows the cam chain and maintains the proper tension.
The surface is hard anodized from super duralumin.

■Drain bolt with magnet (Silver)
The main body of the drain bolt is made of finely machined aluminum with color anodized surface.
The magnet on the drain bolt absorbs the iron powder mixed in the engine oil with strong magnetic force.
This reduces the amount of iron powder in the oil and enables the engine oil to exhibit its original stable lubricating performance.
Furthermore, SP Takegawa's aluminum drain bolts are equipped with a wire lock hole to prevent the bolts from falling off and a hole to insert SP Takegawa's stick temperature sensor.
It is possible to measure the temperature at the drain bolt part by purchasing SP Takegawa's compact LED thermometer (with stick temperature sensor) or various meters with thermometer separately because the stick temperature sensor can be installed.