Fast Road Head
The Fast Road head is fully reworked before the guides, seat inserts and bulleted bronze guides are fitted. The inlet and exhaust ports are modified to enhance air flow without increasing the port sizes to any great extent. This keeps the port velocities high and aids the production of low rpm torque. The inlet valves are 1.625" and the exhaust valves are 1.343".
Bhp is increased from idle to a maximum at 5200 rpm with a standard camshaft. There is a gain of approximately 25% at 3000 rpm and a maximum increase of approximately 30% at 5200 rpm (with a standard camshaft and K&N filters).
This specification of head works well with a standard camshaft and shows even more impressive gains with a Piper HR270 or Piper HR285 camshaft....( mild road and fast road type cams ).
While the head works extremely well with the standard twin SU's it will show worthwhile gains with twin 1 3/4" SU's, I would recommend the fast road HR285 type cam to compliment the increase in carburetion.
Fast Road Head