I would like to know what a complete n/a 13b would weight and what a complete 12a would weight, Im thinking no ac no power steering and lightweight flywheel minimal weight sort of engine for a kit car. I've seen tidbits here and there but they have all been different so I would just like some clarification. Also it seems that the only reason a 13b would have any power advantage over a 12a would be from displacement, correct? Well Ive heard of P ported 13b's in the low mid 300's rwhp range, what about P ported 12a?

 

The best 12A P-port motor for road racing makes about 300 flywheel horsepower. I have run both on road race tracks, and the 13B will jump the 12A a car length or two coming off the turns. The bigger displacement motor just makes more torque, so it comes off the turns harder, plain and simple as that.