I am considering a Penn Yan Aero O-320 Fixed Pitch, 160 hp ($19,900). (Check out Mattituck also)
Is the price of an electronic ignition system worth it? What system (SLICK, Lightspeed) is better and why? What is the difference between Plasma II and III? What pickoff is better, crank or Hall Effect? (Big question, yes EI is well worth it. Magnetos are fine but if you are starting from scratch and get a good credit on the magnetos go EI. Mattituck gives a fair credit off the price of the engine to sub an EI for the mags. Last I checked if you get a Superior engine direct they basically tack on the cost of EI to the basic engine which has the cost of the mags already, so you are paying for the mags and you dont get them. If the engine builder will install it, the crank pick up for the LS is lighter, cheaper and reliable. Nothing wrong with hall effect magneto drive set-up, but you have than have to buy expensive magneto gears. Use Lycoming/ECI PMA mag gears not experimental gears that E-mag/P-mag uses. Nothing wrong with the P-mag/E-mag EI units but they so sell some "aftermarket" gears and there were some early problems. They are cheaper like $80, where the lycoming/ECI gears new are about $250. You can find mag gears used for about $80. As far as aviation plugs vs. auto plugs being better, per Bill Repucci, they are cheaper but they have less performance, which is documented. There also have been a few problems with the auto plugs getting too hot and malfunctioning, although rare it happens. I do agree with Bill that the P-mag/E-mag option is a good one, and they do have an aviation plug harness option. If you go with LS EI you have to go with autoplugs because they don't offer a harness for aviation plugs. LS is a top of the line EI with a little more installation and you may elect to install a small aux back-up battery. The P-mag as mentioned is self powered like a magneto but with the advantage of EI. The absolute performance of the LS should be a little better than the p-mag/e-mag. Also the LS has more features (rpm, map, advance readout and cockpit advanced option. For daily flying the P-mag/E-mag is good enough.)
Is an In Line starter worth the extra $160? (No, a basic Flyweight Skytec is fine. You can go up to their wire wound model; The top of line inline is for airplanes with retract gears that the other models of starters don't fit.)
On the lower compression engine is it worth Porting, Polishing, and Flow Matching ($1300)? What is a piston cooling oil nozzle kit ($85)? (You are building an RV-9A not a reno racer. Save your money. Piston cooling is for turbo-charger, high compression. Build up a stock (I)O-320 with EI. I like Carb over fuel injection for cost and simpler installation, but that is a whole debate in itself. The main reason for FI is better gas mileage, but in small engine like a 320 the advantage is smaller the say a bigger 360 or IO-540. )