Yeah, we'd all like a 200 lb 250 HP installation. You might come close to that, if you're willing to use some of the newest snowmobile/watercraft engines out there. The Yamaha RX1 & similar snowmobile engines (some over 10 years old now, so available on the used market) are around 140 HP with 120 lb core weight. There are installations flying at a claimed installed-weight of around 200 lbs. Newer stuff is even more powerful, but then the 15 lb Rotax C gearboxes (and similar products) start getting pretty marginal & you're forced back to the 40+ lb aviation reductions.

The Renesis core is ~185 lbs, IIRC. A Lyc 320 core is around 285 lbs, and a 360 (fairer comparison) is around 295 lbs, best case, and weights vary quite a bit, depending on numerous factors. Lyc's published sheets for various models show amazing spreads in weight of the same cubic inch engine. The 200 HP angle valve 360 with counterweighted crank is closer to 330 lbs, bare. No, that's not a misprint.

Remember, not everyone weighs their complete install, in everything-required-to-run trim. Even that number doesn't include the 2 stroke oil tank, and now that I think about it, heater hose or caps for the heater ports. Also remember that almost no one *ever* weighs  a Lyc installation, in ready-to-run trim. Most Lyc drivers don't even know what their core engine weighs; they don't need to, since the plane was designed around the engine.

My 1st weighing of my install was at 310 lbs, for what I *thought* was just about everything. Then I decided to try for 2 alternators (with mounts, extra pulleys, etc) and there are always several bits & pieces you forget until you get closer to actual running trim. 

Lighter is do-able. Remove 1 alt= ~10-11 lbs, when you include the extra pulleys, belt, etc. I tried to be as careful as possible with mount adapters, and did pretty well. But I could probably save 2-3 lbs if I built a 'gen2' mount system. The oil cooler is almost certainly oversized, since Tracy is cooling a 3 rotor with the same cooler, so maybe 1 lb less. The radiator could be replaced with a pair of automotive heater cores (like many early builds), but I doubt you'd get more than a lb or 2 for likely marginal cooling because building an efficient diffuser for them is pretty hard. The *complete* exhaust, from modified Mazda manifold through the tailpipe weighs just under 20 lbs. A stainless header would save a couple of lbs (but not as much as you might hope), and a smaller muffler (the Aeroturbine is *big*) might save another 3-4 lbs. Don't expect to save much more than this on the exhaust, unless you're planning on a special issuance Medical for hearing disability (and a 13B would be worse).

So I'd consider 310 - 315 lbs an achievable target for a Renesis. Hopefully, others will share their 'all up' weights, as well. Hopefully, Tracy will share his all-up weight on his Renesis install. I know he was very focused on minimizing weight. Dennis Haverlah might have a good weight for a header type exhaust; I think he's been testing one. (hint hint)

Charlie