Valve Seals

Valve Seals: The Small Part That Keeps Oil Out of Your Combustion Chamber

A valve seal rides on the top of the valve guide and wipes oil off the valve stem as it slides up and down. Do the job right and you meter just enough oil to lubricate the stem while keeping the rest out of the chamber and the port. When valve seals harden, crack or take a set, you get oil burning on startup, blue smoke on overrun, and fouled plugs. People fit fresh ones during a valvespring change, a head rebuild, or any time an engine burns oil without failing a compression test. If the guides are still in spec, new seals are the cheapest fix you will make.

What ThreePiece stocks

There are 17 products in this category from 7 brands: GSC Power Division (8 of them), Supertech (4), plus single listings from Cometic Gasket, COMP Cams, Skunk2 Racing, S&S Cycle and Ferrea. Prices currently run from $29 to $323 for what is in stock right now, not a locked promise. The spread reflects what is in the box: single-engine kits sit at the low end, while bulk sets carry the top price, like the GSC EJ-series 6mm set of 500 at $323.04. Product names reference Toyota, Dodge, Subaru, Ford, Honda, Acura, Nissan, BMW and Audi applications.

How to choose

Buy to the engine and the count you need. If you are doing one head, a matched kit like the Skunk2 Viton valve stem seal kit at $53.11 covers the whole job in one part number. The COMP Cams positive-stop PTFE set for the 5.7/6.2/6.4L HEMI at $44.99 gives a fixed seal height, which matters when you are chasing spring-installed height. Check the stem diameter listed in the name: the Ferrea 5/16 / 8mm .500in ID set of 16 and the GSC Gen 3 Coyote set of 32 with integrated spring seat are cut for different valvetrains. Motorcycle builders will want the Cometic Twin Cam 1550 valve seal at $166.18. Match the seal to your valve stem size and your guide OD first, then to the brand.

What else you need with them

Seals go in with the springs out, so it is a natural time to look at your head gaskets and a full gasket kit while the head is off. If you are this deep, check your bearings and pistons too. Browse the full engine components section for everything else on the shortlist.

Fitment and ordering

Confirm stem diameter and guide size before you order. For help, call fitment support at 813-535-5801 or reach us through contact us. All orders ship free, and Affirm and Katapult financing is available at checkout.

Valve Seals: The Small Part That Keeps Oil Out of Your Combustion Chamber

A valve seal rides on the top of the valve guide and wipes oil off the valve stem as it slides up and down. Do the job right and you meter just enough oil to lubricate the stem while keeping the rest out of the chamber and the port. When valve seals harden, crack or take a set, you get oil burning on startup, blue smoke on overrun, and fouled plugs. People fit fresh ones during a valvespring change, a head rebuild, or any time an engine burns oil without failing a compression test. If the guides are still in spec, new seals are the cheapest fix you will make.

What ThreePiece stocks

There are 17 products in this category from 7 brands: GSC Power Division (8 of them), Supertech (4), plus single listings from Cometic Gasket, COMP Cams, Skunk2 Racing, S&S Cycle and Ferrea. Prices currently run from $29 to $323 for what is in stock right now, not a locked promise. The spread reflects what is in the box: single-engine kits sit at the low end, while bulk sets carry the top price, like the GSC EJ-series 6mm set of 500 at $323.04. Product names reference Toyota, Dodge, Subaru, Ford, Honda, Acura, Nissan, BMW and Audi applications.

How to choose

Buy to the engine and the count you need. If you are doing one head, a matched kit like the Skunk2 Viton valve stem seal kit at $53.11 covers the whole job in one part number. The COMP Cams positive-stop PTFE set for the 5.7/6.2/6.4L HEMI at $44.99 gives a fixed seal height, which matters when you are chasing spring-installed height. Check the stem diameter listed in the name: the Ferrea 5/16 / 8mm .500in ID set of 16 and the GSC Gen 3 Coyote set of 32 with integrated spring seat are cut for different valvetrains. Motorcycle builders will want the Cometic Twin Cam 1550 valve seal at $166.18. Match the seal to your valve stem size and your guide OD first, then to the brand.

What else you need with them

Seals go in with the springs out, so it is a natural time to look at your head gaskets and a full gasket kit while the head is off. If you are this deep, check your bearings and pistons too. Browse the full engine components section for everything else on the shortlist.

Fitment and ordering

Confirm stem diameter and guide size before you order. For help, call fitment support at 813-535-5801 or reach us through contact us. All orders ship free, and Affirm and Katapult financing is available at checkout.