RV-9A's and Engines
The -9A is the nicest flying model of all the VANS range, and I've flown or instructed in them all - right up to the -10. With 15% more wing area, and longer span, plus bigger flaps, I've believe the -9A to be the best marque for the average PPL. Sure, it's non-aerobatic, but if you want to yank & bank - then go for the -7A.
I've found the -9A to have probably the best glide of all the RV's, and it gives a smoother ride in rough air too - important out here.
Engine choice is controversial, because VANS himself recommends against anything higher than 160HP. His concern is exceeding design limits in rough air,especially at higher altitudes. You can read his article on
www.vansaircraft.com An opposing view is available on the Superior site,
www.xp-360.com, which isn't surprising as they have only had a 180HP engine until recently. After flying 43 years in hot climates, I'm very aware of keeping the speeds down in rough air - so I am careful to pull off power as needed. But, the higher HP is really great to get up to 8-10,000 quickly so that it's cruising in smoother air.
I have flown the -9A with a 160HP Lycoming and fp Sensenich propellor, the -9A with 180HP and a fp Sensenich, and a -9A with a 170HP Jabiru with fp Sensenich 'wood' prop. The 180 with the 86 ins metal Sensenich is the best - you get the performance that you pay for !
There are several -9A's flying in the USA with 0-235 Lycomings,(115HP),and their owners swear by them, but it's a 30 knot lower speed you're looking at, and slower climb. When you look at the fuel consumption, the 0-320 is probably 3-6 LPH heavier on fuel, but has advantages. Remember that Jon Johansen flew his RV-4 twice round-the-world with only 150HP, and he used 24LPH for 140KTAS - not bad at all.
Of course, if LSA comes into your country with a 720-750 kg AUW limit, then the -9A with a 115HP Lycoming will be legal, as VANS has it listed as 727kg AUW with that engine- 795kg with the 0-320 Lycoming. So, you'd be able to get out of GA, and into LSA.....if that's going to be an advantage there.
There are lots of other engines for RV's, but my observations are that you are wise to stick to Lycoming or Superior, because the knowledge base of the RV 'airforce' is based on them. Someone, somewhere on the planet, will have an answer to your question....see
www.vansairforce.com and you'll be amazed at the collective experience there alone.
Good luck with your building,