Cyl Mid Sleeve Set Honda B18 81mm

The Cyl Mid Sleeve Set Honda B18 81mm from DARTON SLEEVES is a precision-engineered cylinder sleeve kit designed for serious B-series engine builders and performance enthusiasts. This four-piece sleeve set addresses one of the most common wear issues in higher-mileage or heavily modified Honda B18 blocks: cylinder wall degradation that compromises compression, oil control, and ring seal integrity. Whether you're restoring a tired engine or preparing a block for forced induction, these mid-sleeves restore bore geometry and extend engine longevity without requiring a complete block replacement.

Each sleeve in this set features a 3.180-inch bore, 5.500-inch height, 3.750-inch outer diameter, and 0.285-inch wall thickness, manufactured from durable steel to withstand both naturally aspirated and turbocharged applications. The mid-sleeve design means these liners are pressed into the block at mid-height rather than fully seated, allowing for precise bore correction while preserving original deck height and maintaining OEM-spec piston dome clearance. The 81mm sizing is critical for B18 blocks—it offers the optimal balance between bore correction and material thickness to handle elevated boost pressure, high RPM operation, and aggressive fuel mapping without risk of sleeve failure or uneven wear.

These sleeves are essential for any Honda B18 engine rebuild—whether for street performance, time attack, or drag racing applications. Installation requires honing equipment and professional machine shop expertise to ensure proper press fit, concentricity, and finish boring to your target bore size. The complete set of four sleeves covers the entire block, making this the standard solution for B18 engine builders seeking reliability above 8,000 RPM or boost levels exceeding 15 PSI. Proper installation combined with quality piston and ring selection will restore your B-series block to like-new cylinder condition and support thousands of reliable miles or competitive seasons.