Cylinder Heads & Engine Blocks for Honda CRX EH

Cylinder sleeves and bare engine blocks are the base of a high-output engine, because the bores must stay round and sealed under combustion pressure. This category holds dry, wet and integrated-deck sleeve kits for re-sleeving a block, and aftermarket cast iron blocks listed by engine type.

Under boost, or once the bores are opened up, the cylinder walls flex more at peak pressure. A thin factory liner or an open-deck block can then crack or go out of round, so the rings seal less well and head gaskets suffer. A sleeve replaces the bore wall with a stronger cylinder.

A dry sleeve is pressed into a bored-out cylinder and stays surrounded by the block, with no coolant touching it. A wet sleeve is the cylinder wall itself, with coolant on its outside, sealed at the deck and by O-rings at the bottom. A flange at the top locates the sleeve at the deck and stops it moving down.

Start from the build plan and the finished bore:

• Sleeve type: dry, wet or integrated-deck. Integrated-deck kits are a separate system with their own machining steps, so follow that maker’s procedure. Single- and double-flange designs are listed.
• Bore range: sleeves arrive undersize and are finished to suit the pistons; one is supplied at 86.74 mm for a finished bore of 87.00 to 90.00 mm.
• Wall and flange: wall thicknesses run from 2.54 to 8.94 mm, and descriptions give the flange diameter and thickness, such as 12.70 mm.
• Blocks: cast iron, including 220 BHN (Brinell hardness) cast iron and Class 30 grey iron. Deck heights are 9.025 in or 8.625 in, and bores 4.125 in or 86.00 mm. Descriptions note details such as four-bolt steel main caps, 1/2 in head studs and screw-in core plugs.

Sleeving is machine-shop work: the block is bored to the fit the sleeve maker specifies, the sleeves are installed and the deck is machined flat. Finish-hone the bores with a torque plate fitted, so they are round with the head clamped down. Choose a head gasket whose bore suits the finished size, check wet-sleeve protrusion above the deck, and pressure-test the water jacket before assembly.

On a new block, clean every gallery, chase every thread and check the main bore alignment. Deck height fixes the space for stroke, rod length and piston compression height, so measure it before ordering pistons and rods.