VALVES

SI manufactures a wide variety of valves, ranging from
economical replacement models to highly sophisticated
competition designs —including titanium. Our categories include the following series:

PORTFLOW
SERIES 1

Thanks to high volume robotic production, this series gives you the quality of a competition valve at the price of a street version. Features include premium grade stainless steel forgings, chrome stems, stellite tips and swirl-polishing. The Portflow valves are part number coded SEV.


Portflow Series 1 Valves

PORTFLOW
SERIES 2

Thanks to high volume robotic production, this series gives you the quality of a competition valve at the price of a street version. Features include premium grade stainless steel forgings, chrome stems, stellite tips and swirl-polishing. The Portflow valves are part number coded SEV.


Portflow Series 2 Valves

SILVER LINE INCONEL
SERIES 1

Manufactured from X751 high nickel content material, they are designed for total reliability in extremely high exhaust gas temperature found in supercharged, turbocharged and nitrous oxide-boosted engines. Features include one-piece construction, hard chrome stems and stellite tips.


Silver Line Inconel Series 1

SILVER LINE INCONEL
SERIES 2

Manufactured from X751 high nickel content material, they are designed for total reliability in extremely high exhaust gas temperature found in supercharged, turbocharged and nitrous oxide-boosted engines. Features include one-piece construction, hard chrome stems and stellite tips.


Silver Line Inconel Series 2

SILVER LINE TITANIUM
SERIES 1

Perfect for high RPM racing engines, SI utilizes premium grade 6242 titanium alloy for the exhaust valves and 6AL4V on the intake side. All feature one-piece forgings, swirl-polishing and moly coating. Hard tips can be installed if desired. Available in domestic and metric sizes custom made to your specs.


Silver Line Titanium Series 1 Valves

SILVER LINE TITANIUM
SERIES 2

Perfect for high RPM racing engines, SI utilizes premium grade 6242 titanium alloy for the exhaust valves and 6AL4V on the intake side. All feature one-piece forgings, swirl-polishing and moly coating. Hard tips can be installed if desired. Available in domestic and metric sizes custom made to your specs.


Silver Line Titanium Series 2 Valves

CUSTOM VALVE
SERIES 1

SI maintains an inventory of popular "blanks" and can finish them off to your specifications…providing you with truly custom-sized valves at very competitive pricing. The Custom Series includes steel, stainless steel, Inconel or titanium offerings. Larger runs can be private labeled at the factory.


Custom Valve Series 1 Valves

CUSTOM VALVE
SERIES 2

SI maintains an inventory of popular "blanks" and can finish them off to your specifications…providing you with truly custom-sized valves at very competitive pricing. The Custom Series includes steel, stainless steel, Inconel or titanium offerings. Larger runs can be private labeled at the factory.


Custom Valve Series 2 Valves

SEAT SAVER®

This popular new series is designed for rebuilding cylinder heads with minimal seat work. The valve heads are .030" oversized, yet everything else is stock —allowing you to use valve guides of choice. They're available for a wide variety of popular applications.


seat saver series valves

REPLACEMENT

These economical stainless steel valves are suited for stock rebuilds, and ideal for older engines needing to run unleaded gas. They are available with +3 and +15 stems, and many are offered with "Black Knight" coating. For domestic, foreign and motorcycle applications.


Replacement Series Valves

COMPETITION/PREMIER

Excellent flow characteristics —especially at lower lift— and lighter overall weight for higher RPM capabilities make these an superb choice for high performance engines. Attributes include chrome stems, stellite tips and swirl polishing. They're great for improving the flow of stock heads!


Competition Premier Series Valves

SILVER LINE STAINLESS

Designed to compare favorably with top-of-the-line offerings from other manufacturers, SI's Silver Line stainless steel valves feature undercut stems for improved flow, swirl polishing, chrome stems and stellite tips. Aftermarket head applications start at .050" longer. Also available with hollow stems.


saver

BLACK KNIGHT

SI's unique "Black Knight" valves (code: BK) come with a special coating that serves two purposes; to improve heat transfer for increased valve train life, and to combat the problems associated with lower quality unleaded gasoline. Carbon build-up with these valves is almost non-existent.


black knight series valves