Description
Prevent oil contamination in your combustion chambers and eliminate oil consumption past your valvetrain with the COMP Cams Viton Valve Seal for GM LS1 / 8mm Valves (Part # 511-1). Engineered for high-performance and racing cylinder head assemblies, this premium positive-stop valve stem seal combines a metal body shell with an advanced Viton rubber sealing element to deliver exceptional heat resistance, tear strength, and chemical durability under extreme operating conditions.
Designed with a compact .600 in. outer diameter, the 511-series seal provides vital inside-diameter clearance for modern dual and beehive performance valve spring assemblies. Sized specifically for .313 in. (8mm) valve stems and machined .500 in. valve guides, this individual replacement seal ensures precise oil metering to lubricate the valve stem without allowing excess oil into intake ports or exhaust tracts.
Seal Dimensions & Specifications
| Specification | Measurement / Value |
|---|---|
| Valve Stem Diameter | 0.313 in. / 8mm (0.315 in.) |
| Valve Guide Outer Diameter (O.D.) | 0.500 in. (0.494 in. – 0.500 in. guide boss) |
| Seal Outer Diameter (O.D.) | 0.600 in. (Provides clearance for dual valve springs) |
| Seal Material | High-Temperature Fluoroelastomer (Viton®) with Metal Jacket |
| Seal Retention Style | Positive Stop / Press-On |
| Quantity Sold | Sold Individually (1 Each) |
| Manufacturer Part Number | 511-1 (Set of 16: Part # 511-16) |
Engine Compatibility & Application Notes
- Engine Platform: GM Gen III, Gen IV, and Gen V engines utilizing 8mm valve stems (LS1, LS6, LS2, LS3, L92, L99, LSA, LT1, LT4) equipped with aftermarket .500" OD bronze or machined valve guides.
- Aftermarket Cylinder Heads: Direct replacement seal for popular aftermarket cylinder heads (AFR, Trick Flow, Brodix, SDPC, Dart) machined with a .500" guide OD.
- Spring Clearance: Slim .600" body allows proper clearance inside small-ID inner springs on dual spring assemblies (such as PAC, PSI, and COMP Cams dual spring kits).
Installation Advice
- Guide Boss Check: Verify valve guide outer diameter with calipers before installation; stock un-machined OEM GM guides often measure larger (.562") and require different seals or guide machining.
- Stem Seal Installation Tool: Always use a dedicated valve seal installation tool or socket that contacts the metal jacket shoulder, pressing the seal straight down until fully seated against the guide stop without distorting the Viton wiping lip.
- Lubrication: Apply a light film of clean engine oil to the valve stem before guiding the seal over the valve stem tip.
Details
Shipping Information
- Item Requires Shipping
- H0.25"
- Ships within 1-2 business days
