Supertech Pistons & Rods

Each Supertech piston kit names its engine, bore and compression ratio in the title. The product data adds the figures an engine builder checks before ordering: compression height, dome volume and gudgeon pin diameter. Bores run from 75.5 to 90 mm, so a kit may suit a standard bore or an oversize. Compression ratios run from 8.3:1, a figure typical of turbocharged builds, up to 13.5:1.

The dome volume is the clearest guide to a kit’s purpose. A negative figure means a dished crown, which lowers the compression ratio, and a positive one a domed crown, which raises it. Where a kit suits both a 2.0 and a 2.3 litre version of the same engine, both compression ratios are given.

Rings are not included. Each listing names the recommended ring set by part number instead, so order the rings with the pistons. A handful of kits are also linked to vehicles, mostly Honda models such as the Civic, CRX and Integra, and a Nissan Silvia (S14) kit. Whenever the compression ratio or the camshaft changes, check the piston-to-valve clearance before final assembly.