Piston crown Cylinder Italkit CI.34.085.GR KTM 85 SX 18-25 d.47mm piston 10º

Italkit Ø47 mm cylinder head insert for the Cylinder kit CI.34.085.GR for KTM 85 SX 2018-2025, specifically designed to work with the Italkit 4279/1 piston with a 10° crown.

If you're building a 2T engine, the cylinder head insert is one of those parts where you can't just fit any one. The shape of the chamber and, above all, the geometry of the Squish directly influence how the engine compresses, burns the mixture, and delivers power.

This cylinder head insert is machined to match the 10° profile of the 4279/1 piston. 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's exactly where you want it: concentrated around the Spark plug and with plenty of turbulence just before ignition.

What do we achieve with this? Faster, more controlled combustion and, with the Squish properly set, an engine that responds more forcefully to throttle input, pulls better through the midrange, and keeps pushing when it starts working hard at high RPM.

And here's the important part: the 10° 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're looking for in a build of this level.

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

Features:

• Diameter: Ø47 mm.
• Specific for the Italkit 4279/1 piston.
• Geometry for a piston with a 10° 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: in an assembly with these characteristics, it is worth measuring the actual Squish once the engine is assembled. It is a critical measurement for achieving the desired performance and ensuring that the piston and cylinder head insert work with the correct clearance.