Cylinder Heading Machining Services

Neil Roper Developments specialise in modified cylinder heads. Our cylinder heads have had proven success in rallying, short-circuit and track racing for many years.

We offer several specifications of cylinder head modifications/upgrades, from fast road to serious competition and race cylinder heads. All cylinder heads have been developed through flow-rig, dyno and track testing.

We provide a number of cylinder head machining services to improve the performance of a cylinder head. These services include (but are not limited to):


Cylinder Head Porting

Cylinder head porting (also referred to as cylinder head gas flowing) is the process of modifying the intake and exhaust ports of an engine to improve the quality and quantity of the air flow. Unmodified cylinder heads are usually not optimal for high performance and require modification to increase fuel and air flow, bringing an increase in efficiency and so subsequently power and torque.

An engine running at high speed experiences resistance against air. Cylinder head porting helps to reduce this, thus increasing efficiency of the engine.

The original cylinder head port wall material can be reshaped. This is a manual process and carbon tungsten die grinders are used by hand.

Camshaft profiles, engine rpm, engine height constraints and other limitations play are variables that play a role, but the difference in port design via cylinder head porting is a major factor in increasing engine performance.


Cylinder Head Polishing

Larger cylinder head ports flow more fuel/air at higher RPM but sacrifice torque at lower RPM due to lower fuel/air velocity. Within intake systems, the surface textured to a degree of uniform roughness to encourage fuel deposited on the port walls to evaporate quickly. A rough surface on selected areas of the port may also alter flow by energizing the boundary layer, which can alter the flow path noticeably, possibly increasing flow.

Exhaust ports within a cylinder head can be smooth-finished because of the dry gas flow and in the interest of minimising exhaust by-product build-up.


Cylinder Head Skimming

Skimming a cylinder head reduces the distance between the top of the engine piston and the cylinder head. This leads to higher compression thus increasing power.

We can also provide engine block skimming.


Valve Seat Cutting and Replacements


If you are interested in discussing your project then please feel free to contact us.  We would be happy to discuss your requirements and provide recommendations.