Single Valve Springs

Switching to a camshaft with more lift, or are your old springs worn out? This category contains valve springs with one spring per valve from Supertech, e.g. for Honda D16, Toyota 4AGE and Mitsubishi 4G63. They are for you if you are building or refreshing your cylinder head.

What a single valve spring does

The valve spring closes the valve again after the camshaft has opened it and keeps the valvetrain in contact with the cam. A single spring does this with one coil spring per valve. Dual valve springs, on the other hand, have an inner and an outer spring. Which type suits your project depends on the camshaft, rpm and the rest of the valvetrain.

How to choose valve springs

• Engine code: the springs are made for specific engines, e.g. Nissan RB25 and RB26, Mitsubishi 6G72 and 4G63, Toyota 20R/22R and Audi/VW EA888. Check the fitment for the specific part number.
• Spring pressure: too little pressure can cause valve float at high rpm, while too much pressure can increase wear on the cam and lifters.
• Lift and installed height: the spring must be able to handle the camshaft's maximum lift without coil bind, and the installed height must match the seats and retainers.
• Lifter type: some springs are designed for hydraulic lifters, e.g. for the RB25 DOHC.
• Quantity: some springs are sold individually, others in sets of 8 or 16.

Installation and how the valvetrain works together

Replace the valve springs as a complete set so that all valves get the same pressure. At the same time, check retainers, seats and valve locks, and measure the installed height during installation. If you want to compare with other types, you can see the full category of valve springs or our Supertech range.

Frequently asked questions

What is the difference between single and dual valve springs?

A single valve spring has one coil per valve, while a dual spring has an inner and an outer spring. The choice depends on the camshaft's lift, the desired spring pressure and the space in the cylinder head.

Do I need to replace the valve springs when I fit a new camshaft?

It depends on the camshaft. If it has more lift or a more aggressive profile, the existing springs may be too weak or coil bind. Compare the camshaft's recommended spring pressure and maximum lift with the spring's data.

Can I just replace one valve spring?

If a single spring is broken, it can be replaced, and some springs are sold individually. If the springs are worn or the engine is being tuned, a complete set is typically preferable so the pressure is the same on all valves.