STK Performance Valve Springs
Dual Valve Spring sets consist of an innerspring and an outer spring per valve.
These springs are rated at 200 pounds pressure compared to a standard production spring of around 80 – 90 pounds pressure.
There are various modifications to ensure the correct fitment of these springs the main factor is to ensure that the customer is aware of the following:
- A 1mm spacer needs to be placed under the spring to avoid damage to the seating area.
- Stainless Steel Billet valves must be used otherwise the force of the valves closing will pull the head off a standard two-piece valve.
- Spring Travel & Spring pressures are crucial and will differ depending on the lift, duration and rpm range.
- The Spring sets are designed for up to 9000rpm, however we have clients revving close to 10 000rpm with reliability.
- STK Cam Buckets or similar should be used, the standard production Camfollowers are not strong enough to handle this spring kit.
Chromoly 4140 Valve Spring Retainers
Chromoly 4140 is a lightweight hardened steel.
This retainer is suitable for VW 7mm stems with 3 cotter grooves.
Use with standard 3-groove cotter.
STK Competition Valve Springs and Retainers are a must if you are considering a Camshaft with High
Lift , intend to run at Higher Rpm ranges for NA & Turbo Application.
STK Performance Valve Springs will eliminate coil bind and valve float when installed correctly and are made from High Quality Chrome Silicone Materials , rated at 8500rpm and suitable up to 14mm of Camshaft Lift.
STK Valve Spring Retainers are lighter and stronger being made from Chromoly 4140.
Installation of the STK REV KIT
1. The Spring Heights and Spring Travel need to be Measured & Adjusted accurately to avoid coil
bind ,breakage or damage to the camshaft lobes.
2. Allow an Automotive Engineering Specialist or a Master Mechanic to install these springs correctly ’cause if you get it wrong it’s gonna hurt your pocket !
Modification of the Cylinder Head maybe necessary in order to ensure reliability when fitting the Spring Kit , so ensure that a Master Mechanic fits these products to avoid damage to the camshafts, valve train and engine.
What Valve Spring is right for your application ?
Keep in mind that Motorsport Companies do not use standard valve springs in their “state of the art“ Cylinder Heads, have you ever wondered
WHY ?
The standard valve spring is designed for a production vehicle which is generally well looked after at a moderate rpm.
Whereas a competition engine is designed to run at maximum rpm whether it be 8 000rpm or 10
000rpm , they need reliability and components that can handle the pounding from the high lift, high duration Camshafts they use.
With this in mind a Cylinder Head or Engine will be destroyed due to incorrect installation or incorrect valve spring applications due to valve float and coil bind.
So, when you decide to build a trick head ensure you do your homework thoroughly and get expert advice.
STK Performance Hi-Rev Valve Springs bedding process !
• Ensure correct Spring Pressures, Spring Travel, Spring Height & Clearances.
• On Initial Start-up limit between 1500 & 2000 Rpm until operating temperatures are achieved.
• Shut-off engine and allow to cool to room temperature.
This break-in period will reduce the risk of Valve Spring failure and prolong the life of your Valve Springs.
