7001 - JWR Offenhauser Dual Port Intake Manifold 4BBL

Description

The JWR Offy Hi-Performance Street Manifold has been available for over 30 years and is still unbeaten in design and overall performance.

This famous Offenhauser inlet manifold was developed in conjunction with John Woolfe Racing (JWR) in the United Kingdom back in the early 80’s, to enable the fitment of American produced speed equipment to the Rover V-8 engine.

Most other manifolds available for the Rover engine are for high-revving, pure horsepower style performance. This low profile design, dual port intake manifold features completely separate runner systems for the primaries and the secondary’s. At low-load, the primaries feed the fuel-air charge through the smaller bottom passages at near sonic speed, improving power and efficiency. When the secondary’s open, their charge goes through the bigger, cooler upper passages. Then in turn, it is rammed into the cylinders when it encounters the high-velocity mix from the primaries. The result is better fuel economy and a 15-30 percent power increase across the whole RPM range.