As I'm snail pacing myself towards a kit order – I have the plans – I spend more hours than I care to admit on contemplating different alternatives when it comes to everything from tail gear to avionics and, engines.

I will use the Patrol for float operations, for sightseeing, for travel and for learning backcountry flying. I want to be able to go to the low hundreds for cruise and I'll operate at "airports" up to say about 6000 feet.

The future availability of 100LL is a major concern, I'm in Swedenn, and hence I want to be able to run it on mogas (with a 5 per cent ethanol blend).

I've looked at, and discarded, auto conversions. Now I lean towards Lycoming clones, more specifically the R409 from Titan (ECI) with electronic fuel injection and ignition from EFII.
I've talked to EFII and the the dual ECU EFII is a "double everything" for redundancy purposes. And it's ok to use with ethanol blended mogas.
I've also talked to Titan and the R409, with Titans latest cylinder/piston combo, is also good to go on as low as 90 octane (RON+MON)/2 ethanol blend mogas. And it's making 230 hp weighing in at about 285 pounds.

Now, the Patrol is "approved" for engines up to 210 hp but even if I can't get a statement from Bearhawk that 230 is ok I can "derate" the power via limiting either rpm and/or manifold pressure until I'm at an altitude where I can go WOT. That would give me a flat rated power of 210 hp up to almost 4000 feet if I remember the formula correctly (assuming ISA of course). A huge benefit, especially on floats. In addition to this, being able to operate at reduced rpm's during take off will reduce noise levels substantially. I routinely did this when taxi-operating a C206 on floats (27/27 really keeps noise and CHT down compared to WOT/2850).

About noise. I'm really keen on getting the Patrol as quiet as possible. I'm looking into possible (light) muffler solutions but I've also initiated contact with Hartzell about their Trailblazer prop, explaining my intended use of the plane and that I'm willing to sacrifice some cruise performance for STOL capability. There's one being tested on a 180 hp Patrol but I'm most interested in a 3-blade version, it should be quieter thanks to reduced tip speed. So far they haven't tried the 3-blade on a 4-cyl but they will.
I have a carbon MT on my Skybolt and I really like the quick response a light prop has.

Please fire away with opinions! Do you have a setup that you recommend? What prop should I use? Is 230 hp too much (can you have too much?)?

Regarding a prop, you might want to get in touch with Jan Carlsson http://www.jcpropellerdesign.com .

Engine - check out Bill's "Building a Javron Cub" over on supercub.org http://www.supercub.org/forum/showthread.php?40889-Building-a-Javron-Cub page 3, #104 and page 7, #241. Lots of good info about engine selection, etc. there.

Tom

Thanks for the tips.

Yes, I'll actually ask Jan. No language barrier makes it even easier

I know Mike Araldi hung a 330hp engine on the 4 place, which is supposed to be limited to 260hp.
I think the limit is mostly around weight hanging on the nose.
I suggest you talk to Bob Barrows about the feasibility of that engine choice.

From an operational perspective, if you're looking at floats, I can't imagine too much power would be a problem for you - provided the plane is still balanced with the engine and floats installed.
If you want maximum STOL performance on wheels, a big heavy engine might not be ideal.

The weight of the R409 shouldn't be an issue, it's roughly 285 pounds which is about the same as a stock 360 parallel valve and way less than an angle valve (or 390).

What do you have in yours?

I don't have the Patrol, I built the 4-place with an IO-540-D

On wheels the T/O is never something to sweat. Landing a really short spot gets the palms sweating though.