The combination of high rpm's, frequent and rapid rpm changes, and a long camshaft drive belt can really tax the valve train of the 928 racer.
The cost of a failure - especially on the interference-fit 32v motors - is very high.
These valve train components have been selected to both lighten and strengthen your valve train. Lighter valve train parts lessen the rotating mass and the amount of torque required by the belt to accelerate or decelerate the valve train, thereby lessening belt failures and also increasing the accuracy of the valve events.
Additionally, we recommend the use of the 39.5mm intake valve instead of the stock 36mm intake normally found on the 928. This is the maximum intake valve that can easily fit into the combustion chamber, requiring only matching valve seats and a little unshrouding to realize a much higher flow rate.
928MS Stainless Steel Valves - Lighter than stock, and less expensive too! In the photos below, our SS alloy valves are the same weight as the stock valve, even though they are larger in diameter. The 39.5mm intake valve that we offer is a key to high-flowing 928 heads. Ideal for street supercharged and turbocharged engines.
928MS Titanium Valves - The top-shelf valve for the racer who demands the best. The lower mass of the titanium valves combined with the matching keepers (locks, cotters) and spring retainers allow for the use of higher RPM and more aggressive cam profiles without the loss of valve control.
Matching Valve Seats - Valve seats specifically designed to compliment the SS or Ti valve you select, for our oversized 39.5mm intake and 33mm exhaust valves.
New Valve Guides - Porsche OEM spec valve guides for the 16v or 32v heads.
Titanium Spring Retainers - Our Titanium retainers are precision CNC machined from aerospace quality alloys, fully heat treated and finished to exact tolerances.
Alloy Valve Locks - Our valve locks machined from premium quality heat-treated steel alloy, which insure precision fit between the spring retainer and valve stem. These locks are stronger than OEM, maintaining proper installed height during operation, and especially useful with high pressure springs.
