If you modify your 1.8 16V wih head and induction etc, it will be quick, but I have to agree that the older engines do give a better power to weight ratio. The 16v lump your talking about is an Ecotec. For example look at the original 2.0 16v giving 156bhp as standard, and the equivelent Ecotec only giving 134bhp. Its the same all the way down. The old 2.0 8v sri 130 lump gives 130bhp and more torque. Think carefully, as its alot of work only to change your mind later!