Quality single piece stainless race valves exclusive to Lewis Engines.

Factory length

standard stem size

2.02 and 1.6 head diameter

MATERIAL SPECIFICATIONS

Both intake and exhaust valves are manufactured from 21-4N stainless steel, which is recognised as a quality material for both performance and race applications. 21-4N materials is able to withstand the high engine temperatures and extreme heat created by turbo and supercharged engines.

21-4N stainless specification is the right choice for performance valves at an affordable price. The high cost and restricted life of Inconel and Titanium valves is not the market position we choose to service.

VALVE CONSTRUCTION

All valves are manufactured from single bar stock.
The bar is heated and the head is formed by a drop forged process.

ONE PIECE FORGED CONSTRUCTION

Original equipment manufacturing are usually a two-piece valve with fusion welded head to stem. The single piece construction makes for a stronger and lighter valve.

OVERSIZE VALVE HEAD

Every  valve has a larger head than the original valve. The larger intake valve allows for increased intake air/fuel volume to the engine to improve power. The oversize exhaust valve increases the escape of exhaust gas from the engine. Both of these features improves engine performance.

HARD CHROME STEMS

All valve stems are hard chrome plated. This process extends the life of the valve. Chrome also has micro holes which carry micro drops of oil to the valve stem and valve guide to reduce friction and heat.

SWIRL POLISHED – UNDER  VALVE HEAD

The surface under the valve head on the intake has been swirl polished to direct the intake fuel/air mix. The concept of swirl polishing is to create a mini-vortex into the chamber of the cylinder head. The same applies to exhaust gas flow. It’s all about producing maximum benefits from valve operations.

STELLITE TIPPED

Again, this is another positive step to enhance valve operation and engine performance. All valves are fitted with a stellite tip during manufacture.

Imagine the number of times the valve tip makes contact with the rocker arm during the life of an engine and then relate this to a performance application where the engine rev range is way beyond a stock engine. The stellite tip reduces wear on both the valve and rocker arm. This small add-on feature to the Pep-Pro valve improves the overall performance and durability of all valve components.

NITRITED FINISH

Some engine builders prefer a nitrited finish on the valve stem as it improves the lubrication of the valve stem and guide on dry start-up.