Kimmo, how much hp are you aiming for? If you need more than 146hp, you probably need more cc. 100hp/l isn´t easy to achieve with a 8valve pushrod engine but it has been done before, with some reaserch, right parts and lots of tuning it´s possible! I have heard about N/A A-series engines producing over 100hp/l but I have never seen any evidence/dynopapers, I know that it´s possible but I don´t think many hobbyracers could afford it. With 82mm stroke and 80mm pistons you get 1650cc, with 100hp/l that would give 165hp! To achieve these figures you need a cylinderhead with superb flowfigures, combined with the right camshaft and a welldesigned intake with throttlebodies and welldesigned extractors. The bottomend must be built with raceparts except for the crankshaft, a lightened and wellbalanced A15 crank is strong enough for these powerfigures. The compratio must be atleast 12:1. To get even bigger enginecapacities you could regrind the A15 crank or use the E16 crank to get a bigger stroke but that gives higher pistonspeed and that´s a big problem. With 82mm stroke and 8500rpm the pistonspeed is already close to the limits!?

Marcus