A major drawback to building a high performance experimental with a certified engine is the increasing costs of engines with no end in sight. The experimental market has used so many that the supply has really tightened up. Lycoming 4 cylinder factory overhauled engines start at about $80,000.00 with a $28,000.00 plus core charge. And no stock.

And that turns people into hoarders. This is from last week, it makes 6 engines in my basement. All off facebook marketplace as cheap gambles - I need enough good parts to make 2 engines. My wife says I have a problem. I tell her my only problem is that she keeps going into the basement.

Any non certified engines making an impression yet? Saw a few auto conversions but can only imagine they are extremely loud with the high rpm’s

The engine in my Lancair was a high-compression O-290-D2. It was definitely experimental because it was built (by Don George in Orlando) with an O-320 crankshaft and high compression pistons. But it started as a tried and true Lycoming. I would strongly advise against using a non-aviation engine. Those will cause you nothing but trouble.

to be fair, the corvair makes a fine airplane engine, better than it was as a car engine. But that's not in the power class being discussed in this thread

You can do the work on an E-AB that someone else built. You can't do the annual Condition Inspection, but you can do all of the "while you're doing the inspection anyway" things. On the RV-7, I do everything but the actual inspecting (because I can't legally) and compression testing (because it's a two-man job). Besides, it's smart to have a set of qualified eyes look things over occasionally.

Are availability of the Continental Titan or Lycoming Thunderbolt engines and cylinders any better than the certified engines?

How is Rotax availability?

to be fair, the corvair makes a fine airplane engine, better than it was as a car engine. But that's not in the power class being discussed in this thread

I have impressions of auto conversions, but they aren't favorable. The engine blocks have an almost perfect safety record because one of the accessories will fail and bring the plane down long before the engine itself gets old.

I lost a friend to a PSRU failure recently, and the NTSB files are full of dozens more.

You do have a problem.
How come they’re not upstairs where you can smell and touch them when you walk by.

There are so many PSRU failures, it makes we wonder if some people are using the engines book torque figure to calculate the required sizing rather than the maximum instantaneous peak torque, which is significantly higher.
http://www.epi-eng.com/piston_engine_te ... ngines.htm

Take a look at the latest issue of Sport Aviation and the article on the Rutan Defiant. I've built 3 LongEZ's and a couple of other fast glass birds...and helped build a Defiant. If wanted a HBX to fly IFR and take my family I'd be looking at finishing off one of a couple of half built Defiants in the US, or perhaps buy one of the flying birds. If a centerline thrust twin doesn't turn you on, the RV-10 is a good candidate and easy to build...but expensive.

The Defiant is a nice flying plane; I have 60-70 hours aggregate in two with 320's and one with TIO-360's. They don't fit in most std T-hangars, the canard is too long.

Dick

It's not just a "buy or build" choice, you can do both. Whatever you're thinking of building, buy one and fly it for a while. You'll find out what it's like in the experimental world, and whether your concerns, e.g. finding an A&P to do the annual, are significant or overblown. You'll also learn a lot about the plane, the mods and options available, what you like and what you'd like to change. Mods are so much easier with an E-AB vs. certified that you may find you can customize it to your liking, or it may convince you to build to get exactly what you want. Either way, you'll know.

After I built the Evo, this was actually my wife's suggestion for what we should have done, bought one to fly, live with and learn about as I was building. I confessed that I'd thought of this early on but knew better than to bring it up.

I don’t wonder; I’m certain.

They also don’t know what torsional vibration is.

What about the newer rotary engines? How would they compare?