Supertech Nissan KA24 90mm (+1) 1.339in CH -18.5cc Dish 9.5:1 CR Piston - Set of 4 (Excl Rings)

This is a set of four Supertech forged pistons designed for Nissan KA24 engines. These pistons measure 90mm in bore diameter and feature a dish volume of -18.5cc, resulting in a 9.5:1 compression ratio when installed. This set is specifically for the KA24 engine and comes without piston rings, which must be purchased separately.

Forged pistons are known for their strength and durability, making them a solid choice for rebuilding or upgrading your engine. The 90mm bore size is a +1mm over the stock bore, often used when an engine block has been bored out to clean up the cylinders or to increase displacement slightly. The compression height (CH) of 1.339 inches is a critical measurement that ensures the piston sits correctly in the cylinder, with the top of the piston flush with the deck surface of the engine block at Top Dead Center (TDC) when used with the correct connecting rod length. This specific compression ratio of 9.5:1 is a popular target for naturally aspirated builds or mild forced induction setups, offering a good balance between power and reliability.

When rebuilding an engine with these pistons, it's important to ensure your connecting rods and crankshaft are in good condition. Proper balancing of the rotating assembly is also recommended for smooth operation and longevity. Remember that piston rings are not included with this set, so you'll need to select the appropriate ring set for your 90mm bore pistons and engine application.