Valve Spring Seat Locators

Are your new valve springs sitting directly on the aluminium of the cylinder head? Valve spring seat locators sit under the spring, centre it and spread the load onto the cylinder head. They are for you if you are fitting dual springs, beehive springs or stiffer springs in an engine build and want the spring to sit correctly.

What does a valve spring seat locator do?

The seat sits between the cylinder head and the valve springs and keeps the spring centred around the valve stem. Without proper centring, the spring can walk and wear into the cylinder head, especially when it is made of aluminium. Some seats have a collar that guides the spring from the inside, while others are shaped like a cup that surrounds the outside of the spring. A few kits combine the seat with a valve stem seal, e.g. Edelbrock Locator/Seal Kit Beehive.

How to choose the right seat

The choice depends on the spring and the cylinder head, not on a single measurement:

• Spring type: seats for dual springs and beehive springs are shaped differently, and several are made for a specific spring, e.g. Ferrea seats for S10056 or Supertech seats for SPR-M1007D.
• Diameter: the inner and outer diameter must match both the spring and the machined spring pocket in the cylinder head.
• Thickness: the thickness of the seat changes the installed height of the spring and therefore the spring pressure. A seat of e.g. 4.0 mm must be taken into account when you measure.
• Engine: many kits are made for specific engines, e.g. Honda K20/K24A3 or Audi/VW 1.8T 20V.

Measure the installed height with the valve spring retainers and valve locks you are actually using, and check that the spring does not go into coil bind at maximum valve lift from the camshaft. The category includes seats from brands such as Edelbrock, COMP Cams, Supertech and Ferrea.

Frequently asked questions

Do I need new seats when I change valve springs?

That depends on whether the new springs are the same type and diameter as the old ones. If you switch from single to dual springs or beehive springs, for example, the seat typically needs to be replaced as well so the spring is centred correctly.

Does the seat thickness affect spring pressure?

Yes. A thicker seat reduces the installed height of the spring, so spring pressure typically increases both with the valve closed and open. Therefore, measure the installed height after fitting and compare it with the spring manufacturer's recommendations.

What is the difference between a cup seat and a seat with an inner collar?

A cup seat surrounds the outside of the spring, while a seat with a collar guides the spring from the inside. Which design fits depends on the spring, the machined spring pocket in the cylinder head and the space around the valve guide.