4P REAPER CNC Cylinder Head

Introducing the 4P REAPER

Months of development has lead to this.  In 2018 we worked tirelessly on developing a superior port for our Billet K20 cylinder head.  It is a clean slate design that could not fit into any OEM cylinder head casting, and one that outflowed anything on the market by a landslide.  Unfortunately after complaints from our competitors, our Billet head was banned from competition.  We immediately put that energy into developing a race port that has not lost a SINGLE race since that day.  Our warpath has not only won every All Motor race competition since, but has held every record in the class since….the rampage has been so fierce that the competition has all but quit.

In 2021, 4 Piston Racing, Endyn, and MAST Motorsports entered into a partnership for 4P to have exclusive rights to the race casting going forward. This partnership has allowed us to reinvigorate the work we did on the 4P Billet, and deliver the REAPER to you.  These cylinder heads are producing on the track, with competitors seeing 2-3mph gains over the previous record holding 4P Heads.

• High flow intake port that outperforms top to bottom 440+ CFM.
• High flow exhaust port.
• Balanced combustion chamber developed after hundreds of dyno pulls on various engine combinations.
• New Oversized valve seats available in steel and copper beryllium.
• Bronze valve guides standard.
• Newen CNC Valve Job developed specifically for this head.
• RBC Style heads are shipping now, PRB Style heads ship February 2022.

Casting Design Features

As OEM castings have gone out of production, those in the field have aged and worn, and the demands on our race engines have increased, we needed to develop a superior alternative to OEM.  The 4P Race Casting is superior in every way. Exclusively available at 4P.

• Made IN THE USA from A356-T6 Aluminum
• These “porting castings” give us a clean slate to put any port size and shape we choose, and offer a “full cleanup”
• We machine a wide variety of combustion chamber shapes and sizes to suit your application.
• Port wall thickness is increased over OEM dramatically to allow us to run larger ports and move them around for high rpm applications.  Increased port wall thickness also allows for extreme boost applications.
• Extra thick deck for increased rigidity and high boost handling capabilities.
• Superior cooling through 3D printed water jackets
• All heads accept VTEC and non-VTEC arrangement with OEM or aftermarket components.
• These race ported heads are 100% designed, machined, and finished in house at 4 Piston Racing.  We will build you the head you need for your race or street program.
• Heads available in PRB and RSP/RBC Style water jacket arrangements.

• R40 K24Z heads available in 4 Port Exhaust Configurations to fit ANY of our Port Designs.