Cylinder head Cylinder Italkit CI.34.085.GR KTM 85 SX 18-25 d.47mm piston 12º

Italkit Ø47 mm cylinder head insert for the CI.34.085.GR cylinder kit for the KTM 85 SX 2018-2025, specifically designed to work with the Italkit 2984M piston with a 12° crown.

If you are building a 2-Stroke engine, the cylinder head insert is one of those parts where you cannot just fit any one. The shape of the combustion chamber and, above all, the geometry of the squish have a direct influence on how the engine compresses, burns the mixture, and delivers power.

This cylinder head insert is machined to match the 12° profile of the 2984M piston. In this way, when the piston reaches TDC, the squish band maintains the correct geometry and pushes the mixture from the outside toward the center of the chamber. That is exactly where it needs to be: concentrated around the spark plug and with high turbulence just before ignition.

What do we achieve with this? Faster and more controlled combustion and, with the squish correctly adjusted, an engine that responds more forcefully to throttle input, pulls better through the mid-range, and keeps driving when it starts working at higher RPM.

And here is the important point: the 12° piston and this cylinder head insert are designed to work together. If we fit a cylinder head insert with different geometry, we can alter the squish band, the compression ratio, and the shape of the chamber, losing precisely the performance we are looking for in a build of this level.

Combined with the single-ring Italkit piston, we have a setup very much focused on an 85cc Racing engine: less friction in the piston to gain RPM quickly and a combustion chamber designed to take advantage of that rotational speed when the engine starts to rev out.

Features:

• Diameter: Ø47 mm.
• Specific for the Italkit 2984M piston.
• Geometry for a piston with a 12° crown.
• Designed to work with a specific squish band.
• Compatible with the Italkit CI.34.085.GR cylinder kit.
• Application: KTM 85 SX 2018-2025.

Installation tip: with an assembly of these characteristics, it is worth measuring the actual squish once the engine is assembled. This is a critical measurement to achieve the desired performance and to ensure that the piston and cylinder head insert work with the correct clearance.