Key Features & Benefits – Cat Cams LADA valve spring set

The Cat Cams LADA valve spring set uses a dual setup with an outer and inner spring pair for the LADA valvetrain. This layout is aimed at maintaining valve control when valvetrain loads increase at higher RPM.

Geometry is straightforward to match: the outer spring is D 28.6 mm and the inner spring is D 21.3 mm, with solid lengths of 16.6 mm and 13.8 mm. It is not compatible with stock retainers, so the retainer/seat choice needs to match the spring diameters and your installed height.

When is this useful?

It fits builds where you run higher RPM, faster valve motion, or more aggressive cam profiles. In these cases, a dual valve spring setup helps keep the closing action controlled across the working range.

Technical specs

• Design: Dual valve spring (outer + inner).
• Outer spring – free length (Lf): 40.8 mm.
• Outer spring – solid length (Ls): 16.6 mm.
• Outer spring – outer diameter (D top/bottom): 28.6 mm.
• Outer spring – wire diameter (d): 3.6 mm.
• Outer spring – mass: 28 g.
• Outer spring – load reference (length → force): 40.8 mm → 0 kg; 30.0 mm → 34 kg; 20.0 mm → 71 kg.
• Inner spring – free length (Lf): 40.7 mm.
• Inner spring – solid length (Ls): 13.8 mm.
• Inner spring – outer diameter (D top/bottom): 21.3 mm.
• Inner spring – wire diameter (d): 2.5 mm.
• Inner spring – mass: 12 g.
• Inner spring – load reference (length → force): 40.8 mm → 0 kg; 30.0 mm → 16 kg; 20.0 mm → 29 kg.
• Compatibility note: Not compatible with stock retainers.

Selection & installation tips

• Installed height: measure the installed spring length with your chosen retainers/locks, then compare it to the free length.
• Coil bind margin: check total compression at max valve lift and keep margin before the solid length.
• Retainer & seat diameter: confirm the seating surfaces match 28.6 mm (outer) and 21.3 mm (inner) spring diameters.
• Spring load targets: use the listed length → force points to compare against your cam profile and RPM goal.
• Clearances at full lift: verify guide/seal/retainer clearance through the full lift range.

Before installation, measure installed height, retainer/seat geometry, and maximum valve lift. Compare your measurements to the dimensions and the length–force reference points listed above.