Darton MID Sleeves are the best sleeves on the market because of their strength and fitment. Their flanged tops align against each other while still allowing coolant to flow through them. (wet sleeves).

Darton MID Sleeves for Honda/Acura B18 engines replace your factory cylinder liners with high strength iron sleeves, eliminating a weak link in your engine and providing you with the strength needed to get the full potential from your setup without losing any sleep worrying about cracking a factory sleeve and taking the engine out.

MID stands for "Modular Integrated Deck". If you notice the sides of the top of the sleeves are notched so they mate up flush against each other, providing a full rigid structure when assembled, but still able to be replaced individually if needed. As shown in the photo, the top flange has coolant passages and the outside surface of the sleeve contains "fins" that help reduce heat soak within the sleeve, helping keep the heat out of your internals where it could cause damage cracking, warping, etc.

NOTE:
ALL Darton Sleeves come from the factory slightly smaller than stock bore. ALL Darton sleeves must be finish bored and honed to the specs of the pistons going into them. You CAN NOT install a piston into ANY Darton sleeve the way it arrives from the factory. This ensures that you will get the exact proper piston-wall clearance to provide a tight seal in your engine. Your machine shop already knows this, and now so do you.
These are the newer design from the original 400-130-P. This has been revised with a shorter register, also based off our drag kit. Stand Ductile iron spec.

Many production cast iron and aluminum blocks suffer from a design weakness of cylinder stability by nature of poor support at the upper deck area. The manufacturing process of "cast in sleeves" provides for economy of scale in low horsepower engines, but does not accommodate high horsepower, high boost, or larger bore sizes.

Darton has engineered a superior solution by using a unique designed cylinder sleeve which when siamesed and nested,creates a solid deck of sleeve flanges held in tension, reinforcing the upper deck area and provides for in-field replacement with what we call Modular Integrated Deck (MID). In addition, Darton designs' manage and enhance water flow from block to head to promote stability of cooling and all sleeves are of the "Wet" design.

The enhanced water flow in and around the flange area is possible because of ported water flow control engineering we call "swirl coolant technology". This process begins with specific engineering models of respective cylinder head and combustion chamber designs and then we promote increased flow of water in those areas of the upper sleeve area subjected to the most heat. There is a different engineering model for each engine and cylinder design. While heat is generally considered to translate into energy, high resident heat in the combustion chamber can lead to detonation, the single highest cause of engine failure in the high horsepower regimes. High RPM normally translates into efficient scavenging of air-flow but during misfires or incomplete flame propagation, high cylinder pressures and temperatures are created. Our MID design compensates for this high resident heat soak condition.

In the normal dry sleeve installation the cooling medium, water, must transfer heat absorption through block material and sleeves, which may be dissimilar metals. When dry sleeves are pressed in with interference fit, the materials interface is not perfect which further exacerbates heat transfer. This thermal conductivity is inefficient and as more heat is generated, the combustion process is compromised. Even in wet sleeve designs of the past, water is never efficiently processed or flowed between the block and head to provide for maximum heat dissipation in the combustion chamber. Inherent in open or closed deck engine blocks of cast iron or aluminum is a certain amount of water stagnation. This is like pouring water through a funnel, there is really no flow or velocity until the water exits the spigot. In the case of blocks and heads, the casting ports are designed for ease of casting not efficient flow. Now with Darton's "MID", swirl coolant technology the cooling medium is ported and directed to significantly improve heat transfer where it is needed most, in the upper cylinder wall/flange area.

The Darton Pro-Sleeve Kit is available for many series of 4, 6, and 8 cylinder import and domestic engines and provides for maximum bore sizes and boost potential. The benefits of our pro-series kits are:

Improved block integral strength
Improved cooling
"Wet sleeve" replace-ability
Increased horsepower output potential
Superior oil and compression control
Street or strip application
Kits can be installed by your local machine shop
Full installation manual with every kit sale
High boost and horsepower potential · Superior cylinder sealing and ring wear
Bulletproof Darton ductile iron, 130,000 psi tensile strength