B20 DOHC

Of the two B20 engines the B20Z has more compression at 10.2:1 over the B20B's lower 8.8:1. This is because the B20Z has a flatter top piston when compared with the to the B20B's deeper dish. The lower compression B20B is more desirable for a bolt on supercharger or turbocharger kit because of this. If you wanted to run high compression with a B20B/Z there are no factory pistons that can do this, but any number of quality custom forged piston makers, such as JE, Aires or Wiseco can make a piston for the B20B/Z. This piston should be made with a dome volume to give about compression ratios from 11:1 for the street to 13:1 for race gas. With 11:1 pistons and a VTEC head mildly worked over, it can be possible to have a very impressive engine for very little money.