well i've always loved my engines... used to fit 'em for a living. at the moment i have no garage to do a car engine project, my time will come again soon for that...... but... bike engines being small, what's an easy, and relatively cheap to build engine?? i don't want to do a 50cc or anything, coz who's going to want to buy one if all goes to plan?? i want something that's not expensive incase i f* it up, but something that's not so crap i'll never use it for anything. any recommendations?