Continental TSIO 360

[Jconard]

I assume liability and close FAA scrutiny when some tinkerer buys the farm because of unimpressive building / flying technique.

I agree wholeheartedly that it will be a stain on all of us when some tinkerer....can't imagine who.....has a flutter event....and buys the farm because of their unimpressive building technique. As an example of such technique, perhaps it will be a builder who without any basis in fact or design creates an airplane capable of destroying itself...simply because they want to.

Of course, ALL of us are so good that the experience of a professional combat pilot is probably an example of his negligence and has no prescriptive value for the rest of us SKILLED pilots (yes I am being sarcastic).

Why not build a compair? It really seems like the pedestrian performance of the RV series is just not enough for you.

[pierre smith]

.....This seems to be a Universal tendency....always more power. In my business, I've watched Ag airplanes like the early Pawnees with 0-540's derated to 235HP work and carry big loads just fine. Same thing with the Cessna Agwagons and their 230 HP Conti O-470's. Both airplanes eventually had bigger engines...260 for the Pawnees and 300 HP IO-520 Conti's in the Agwagons, and now 350 HP Conti's. It never ends. Heck, my Air Tractor has right at 700 HP. Just fly it with what you have. Van really does know better.

Regards,

[rv6ejguy]

Richard seems to understand the perils of maintaining full SL power to 20,000 feet and using it. That would be foolish.

Assuming that most RV builders are not complete idiots, you can safely fly your turbo normalized RV without it coming apart. Heck you can already get flutter on an atmo 360 powered RV if you just put the nose down 20-30 degrees at WOT and medium altitudes and of course you can stall an RV too. All things like this are up to the pilot. We all know that stalling an RV at 50 feet and pointing the nose vertically down at full power for more than 15 seconds at 15,000 feet is also a bad idea.

I have gone to Vne at 15,000 feet in level flight in my 6A- once, just to see what it would do and to check that it was flutter free there. I have no need to repeat that again. When descending from altitude, power comes back first, nose goes down second. No big deal.

Like any other aircraft, operate it within limits and you'll be fine. Not sure where all the sky is falling comments are coming from.

I haven't pulled the wings off my 6A which has a 182 knot Vne- quite a bit lower than the newer RVs.

A turbo 360 in an RV9 would not be of much use other than high altitude climb performance due to the lower limiting speeds compared to a 7.

Lots of people highly modify their RVs in many ways- 4 place 6s, 390,400 or 540 cubic inch engines, extra fuel tanks, retractable gear, fastback fuselages etc. Do these mods with eyes wide open but really, a turbo normalized 360 is almost a mild mod by comparison. Build what you want.

[Ted Johns]

Originally Posted by richvidaurri

I went back and re-read the article and I don't understand how you missed it. The italicized text under the Vne chart clearly states that the 260 HP engine is 260 HP from the ground up. And that's the engine no one in their right mind would install in an RV-A.
Richard

????
The chart is for an RV-10. For an RV10, 260hp is the standard, recommended engine. However, 260hp into the flight levels via turbo-normalizing is not, and that was the whole point of the article.

Likewise, 210hp with turbo-normalizing is not the recommended RV-8 engine.

And yes, Ross, you could fly behind a PT6 in an RV-8 and stay safe, but you would be throwing away a bunch of money and hp.

I'm not trying to rain on anyone's parade here, nor am I advocating any legislation.
I'm just sticking up for the reasonableness of Van's article and recommendations.

[rv6ejguy]

Come on guys, the premise is just silly here. Only a complete idiot is going to try using the whole 260hp of a normalized 540 in an RV10 at 18,000 feet.

Van's made us aware of the realties of this with their articles on the subject which is good. It is up to builders and pilots to apply this in their aircraft and operations. Turbocharging is an easy way to pick up 10-25 knots without using as much fuel as you would down low.

[Ted Johns]

Originally Posted by rv6ejguy

Come on guys, the premise is just silly here. Only a complete idiot is going to try using the whole 260hp of a normalized 540 in an RV10 at 18,000 feet.

Or even 75% of 260hp @ 20,000 feet, which is where Van says you go negative on the flutter margin.

Turbocharging is an easy way to pick up 10-25 knots without using as much fuel as you would down low.

Yup. (edit: With some misgivings about the word "easy" ...)

[rv6ejguy]

You'll be able to buy the engine from Lycoming in early 2009 I think, complete, ready to bolt up. Duct some air to the integral intercooler and you are ready to go. I say that is pretty easy compared to building the airplane. Lycoming did all the engineering for you and it is a very nice job I might add.

[rv6ejguy]

Originally Posted by richvidaurri

I am considering the purchase of a used RV-8A or an RV-3B which I will strip to bare bones and rebuild to my specifications. I'm not sure yet about the engine; ergo, this question: If I pop in one of those hot rebuilt IO-360s or IO-390s, how high will I be able to fly before performance falls-off noticeably?

OR, lets say I go with the new Lycoming TIO-390-EXP with integral turbo-normalizer. Do you think I will have trouble keeping the ship straight and level up in the Class A levels? Are you able to fly through any weather at all? It's the awfully light wing loading I'm concerned with.

Thanks,

Richard Vidaurri

I think you will find that the first combo will start feeling a bit sluggish at 15-18,000 feet, depends what you are used to. You are down to about 50% power at full throttle up there with an atmo engine.

With the turbo, you can zoom around at 25-30,000 if you have the right oxygen equipment and watch the Vne of course. Bruce Bohannon went up to 47,000 with a highly modified RV and special 540 turbo Lycoming several years back.

In practical use, you can catch the good tail winds up high and pull back to 55% at 20-25,000 and get some fantastic fuel economy if that is your game. In the mountains, you can maintain your SL ROC pretty much right to 25,000 if you can cool the engine properly and that is a nice feeling.

[rv6ejguy]

Originally Posted by richvidaurri

You know, I've asked this question on three different threads and you're the only pilot who's answered it. I can't thank you enough.

Best,

Richard Vidaurri

I'm probably a little more open minded than some of the folks posting here and one of the few with turbocharged RV experience. There is a weight penalty with turbocharging but with Lycoming's good design job on their latest system, I don't think you will see much more maintenance over an atmo model. I often see a lot of people who haven't flown turbos much to have a negative attitude towards them. There is a world of difference in Lycoming's latest system compared to many poorly executed OE turbo systems from the past IMO.

[breister]

Originally Posted by richvidaurri

I was speaking to a tech at Lancair yesterday and asked him about the Vne of the Legacy RG with the IO-540: "It's 274," he said.

"274? But that's less than the cruise speed."

"Yeah, so what? They take them up to 400 MPH at Reno."

"Oh.'

Now that concerns me about the RVs; I'll have to do more research before I decide one way or another.

Thanks for the help...and the laughs.

Ciao forever,

Richard Vidaurri

Hey Richard,

FYI - Vans calculates a reasonable safety margin on Vne for TRUE airspeed; Lancair sets their Vne based on INDICATED airspeed. Thus turbonormalized engines are not nearly so risky in the Lancairs.

Why the difference? For whatever reason, the aluminum construction used on the Van's models is reputedly more susceptible to flutter - I believe it has to do with harmonics, there are bona fide engineers here who will certainly correct me... In that particular regard (and I'm sure others here will chime in with it's relative weaknesses, too) composites seem to have an advantage in naturally damping harmonics.

Thus, if a Legacy's Vne is 276 then you can build a heavily turbocharged version which allows firewalling the throttle at FL250 and getting darned near 270 IAS without exceeding Vne. Special notes: Legacies racing at Reno usually have an additional layer of carbon fiber to stiffen the tail section, and they denounce using a 6-cylinder on the glass version of the Legacy (have to upgrade to the carbon-fiber version).

Vans airplanes are preferrable for grass and aerobatics and vastly superior on smaller budgets, but if you decide to turbonormalize and then fly your Vne as IAS in the Flight Levels you are taking your life in your hands, as you will have exceeded your True airspeed Vne by 50 knots or more.