Carpenter Racing Specializes in 4-cylinder big-bore motorcycle engines

Custom Cylinder Head Porting (5-axis CNC)

We offer the absolute best in big-bore motorcycle cylinder head porting. Unlike other porting shops that offer “stages” of porting with different pricing levels, we do the very best we can do on every head. We don’t hold back. The design of each port differs only based on the base cylinder head design and the size of the valve. Call for availability on your application.

 

Full Radius Valve Job

The most critical, high velocity flow around a valve is right at the valve seat. The full radius valve job focuses on this area. Performed on a Serdi 60 machine utilizing our custom-designed tooling, ensures that valve edges are smooth for the best flow. The valve height is kept at a standard so we don’t loose compression ratio. Many times we can achieve a better seal than at the factory. A full radius valve job alone can yield approximately a 3% gain in horsepower.

 

Porting

In the very competitive world of performance, the manufacturers have made ports more efficient. Because they have other parameters to consider, the engine becomes a restricted package that adds some negative shapes to the ports. Correcting and keeping port volume on target, we do not cut certain areas of the port. Maybe not as pretty as a “polished” head, but definitely faster.

Components

We manufacture our own valves seats for larger ports. Other components include larger tappets and larger valves with options of titanium, stainless, DLC coatings etc. We custom fabricate valve seats utilizing an aluminum bronze alloy. This makes for a happy marriage between seat and valve where no erosion of valve seat or valve face occurs.

Springs

Often overlooked, proper springs are an important part of the valve train. We custom-order our springs from the largest automotive spring manufacturer in the world. Every spring is chrome silicone wire. Every spring is magnafluxed and shot-peened to ensure integrity. Some shops fit existing springs into a head. We design springs for each application.

Cams

Custom cams are an integral part of any serious high-performance application. Cams can compliment porting and larger valves tremendously. Lift and duration are important but ramp speed is the real science. We have many cam profiles to choose from for practically any application. Many are in stock.