velocity XL-RG

[DustMaker]

my opinion, mmmm, well - the rotary is a very strong and easy to rebuild engine, but the fuel economy is a question at this time.

If i were not going continental in my cozy, i would go subaroooo.

The velo rg is a big plane and needs at least 300 hp in my opinion

The evidence is that the rotary takes 30% more fuel than a lycoming, but there is not much evidence as many rotary installations are under way and many are planning on running LOP

time will tell

start buildin and make your engine choice later - plenty of build time to do before the engine must be decided on

 

[rubicon789]

One thing to consider when using a "automobile" engine in an airplane is this:

Aircraft engines are build to produce max. or peak HP at what 2700rpm and still 75% at around 2400rpm. Where as automotive engines do so at much higher RPM's. My inline 6 for example, not a performance engine at all, but at 2000-3000 RPM is only putting out about 100HP or so of the 190 available. However rotary engines need to turn quite high in the RPM department to produce peak HP as quoted from here

The previous 13B-REW engine generated its maximum power output at 6500 rpm, whereas the Renesis power peak comes in at 8200 rpm

http://www.rotaryengineillustrated.com/renesis.php
So thing long and hard before doing an automotive conversion. Mooney tried this with a Porche engine and quickly stopped offering it due to maint issues. My opinion for what it's worth, keep that auto engines in auto's and, aircraft engines in airplanes.

Yes, you will have people one here that have done them and swear by them, however the numbers speak for themselves. Think how long your car engine would last if you were running it at 75% HP alll the time... well you would probably have to rebuild it every so often because it would just fall apart.

 

[DustMaker]

Well rubicon789 i used to think that also. but the reality of it is it just does not hold up. the rotary installs are starting to really prove themselves with many 1000 hour + birds flyin. the subaroos are even more proven.

the problem with auto conversions is weight and systems. most of the engines weigh way too much, so do not make a good conversion candidate and on the ones that do, it is hard to get all of the systems right.

in the 30's, 40's and 50's aviation led in making improvements fast and furious. unfortunately, those days are long gone and it is basically up to people in thier garages to improve the state of the art.

the aircraft engine mfgers have such a small market that they cannot make any real headway in engine development. heck, in the auto world the annual production run for an aircraft engine would not even be big enough for a prototype run.

Now, since you can rebuild a rotary for about $1,000, if they continue to prove themselves as they are, you will also become a convert. the subes are also inexpensive to rebuild and have an excellent track record.

thielert took a mercedes auto diesel and converted it to aviation diesel and under powered for my bird - it is doing very well and is available in many certificated planes.

on the surface - you would seem to be right, but, MANY are proving that the auto engines are more than robust enough.

 

[Huggyu2]

What is "P.O.S"?

 

[DustMaker]

Not a velo, but i believe it stands for "Piece of Sh*&". i would like to know of the problems the fliers have had and would guess that they were systems, spelled "builder design" rather than airframe

Nothing wrong with builder designed - i am doing it now, but that is where most problems in experimental aircraft come from on a widely built and flown airplane like the velocity.

it is not a one, two or even ten of a kind. I would guess there are hundreds flying. plenty enough too have worked out any airframe problems.

 

[Omlet]

Sleek and Sexy yes....Check out the Insurance before you buy. I have read several people either don't build due to extremely high insurance or can't get it. I would love one but the longer runways required don't fit 50% of the flying I would do!

 

[DustMaker]

well - for grass strips - not a canards strong point, but you can shorten up the required runway allot by using a CS prop

on my cozy - no hull ins - if i break it - i'll fix it for next to nothing