DROWsports Honda Grom/Monkey 181cc 4 Valve Performance Cylinder Kit

As low as $964.95

DROWsports LS Grom 181cc 4 Valve Head Big Bore Cylinder Kit is a complete package that includes the top-end components for installing a 4 valve 181cc big bore. The package utilizes our very own 4 valve 63mm Forged Piston and 181cc Ceramic Cylinder.

Details

DROWsports LS 181cc 4v Head Big Bore Cylinder Complete Kit was designed for the Honda Grom and Monkey. We wanted to develop an affordable larger displacement cylinder and piston kit for KOSO 4 Valve Head. The design we've come up with utilizes that and has similar features to the 170cc piston and cylinder but offering more attention to detail. The KOSO 170 is great and we've loved pushing that kit to its limits, but we wanted a little more displacement and a few key features.

Cylinder & Piston

DROWsports LS 4v 181cc Big Bore Cylinder & Piston is an upgrade to the 170cc cylinder and piston kit. This utilizes our very own 63mm 4 valve forged piston. Although forged and machined, these pistons are lightweight and our 181cc piston weighs only a couple of grams more than the 170cc piston. These are all CNC machined for tight tolerances and includes a special frictionless coating. This helps it push 11.5:1 compression ratio for great performance! The machined radius edges and special accumulator groove are some of the extra detailed features we were looking for. We wanted to stick with the 4 valve design because of the performance capabilities and options that it is capable of making.

Cylinder Head

The KOSO 4 Valve Cylinder Head was a perfect pick to work with. The head already comes pre-assembled with a cam, valves, rockers, and seals installed. It head uses 24 mm intake valves and 21 mm exhaust valves allowing it to breathe much better. This is exactly what we needed for our 181cc because having a 63mm piston it is definitely needed.

Engine Building

As enthusiasts, we pride ourselves on building high-performance engines that are designed reliable and consistent. We offer our experience of engine building as an option to assemble the motor. This includes all the options that we do to our personal bikes like WPC treatment, race porting and polish and crankshaft balancing. WPC treatment to engine components offers reduced surface friction making it ideal for piston treatment.

Main Kit Includes