Piston Sets

What compression ratio, what bore and how much boost do the new pistons need to handle? A piston set includes all the pistons for one engine, from 4 to 8 cylinders. It is for you if you are rebuilding your engine or upgrading it for a project with more power.

How to choose the right piston set

A piston set gives you identical pistons for every cylinder, so weight and dimensions match. Some sets come with rings, e.g. CP Pistons' sets for Audi/VW 2.0L TFSI and Toyota 2JZGTE. Others contain only the pistons. If you are missing parts, you will find them under piston rings, wrist pins and circlips.

• Bore and oversize: The pistons must fit the cylinder after any overboring, e.g. STD or +1.5 mm.
• Compression ratio: This depends on the piston crown (dome or dish) and on the cylinder head. Lower compression is typically used with high boost, but fuel and engine management also play a part.
• Stroke and connecting rod: For stroker projects, the piston's compression height must match the crankshaft and connecting rods.
• Engine code: The sets are made for specific engines, e.g. 4G63 Turbo, LS2/LS3 and 2JZGTE.

Installation typically requires measuring the cylinders and piston-to-wall clearance as well as setting the correct ring gap. The required clearance depends on the piston material and application, so follow the manufacturer's instructions for the specific part number. In this category you will find brands such as Wiseco, JE Pistons, CP Pistons and Mahle. If you only need to replace individual pistons, see our pistons.

Frequently asked questions

Why should pistons be replaced as a complete set?

Identical pistons give the same weight and compression in every cylinder. This can reduce vibration and uneven combustion. If you mix old and new pistons, differences in weight and wear can cause imbalance in the engine.

What does the cc figure in a piston set's name mean?

The figure indicates the volume in the piston crown. A negative figure, e.g. -14cc, typically means a dish that lowers compression. A positive figure denotes a dome that raises it. The final compression ratio also depends on the cylinder head and head gasket.

Do the cylinders need machining before a new piston set is installed?

That depends on the condition of the cylinders and the dimensions of the pistons. An oversize set requires boring and honing to the correct clearance. Standard pistons also typically require measuring and possibly honing so the rings can seat properly.