Homebuilt followup

[Debonair]

IMHO if its rotary powered, it should be a Le Rhone.
Theres used to be an EAA Nieuport squadron based either at KSLE or Independence, maybe they can help with that.
Also, you should grow a bigger moustache

[Chairboy]

Originally posted by Debonair
IMHO if its rotary powered, it should be a Le Rhone.
Theres used to be an EAA Nieuport squadron based either at KSLE or Independence, maybe they can help with that.
Also, you should grow a bigger moustache

Heh, different type of rotary.  I'm using a WANKEL.  

[Debonair]

Originally posted by Chairboy
...I'm using a WANKEL.  

I don't care what you do in the privacy of your home...

...Clerget powered swept wing canard would be a great mix of space age & horse and buggy days, like in the 80's when my grandfather bought a Taurus...

[Roscoroo]

i ran a 13b wankel "Mazda" in a datsun 510 2door with an  auto behind it and 4.33 to 1 gears i used a motorcraft 4 bbl carb set up 1 to 1 likea mini domanator and a 2 1/2 primary tube header ith 3 1/2 in collector then thru a super trap muffler ... this thing ran 11.90 in the 1/4 mile and would rev to 14,000 rpm .

this was one of the 30.000 mile Japan recycle engines basically untouched on the insides .. and the guy i sold it to raced it for 5 seasons and put well over 120,000 on it befor it started smoking real bad .. it never broke .

This motor went thru hell .. so thats what my rotory experiance is .

but theres nothing wrong with those Suburu engines either.

[mora]

Rand Cam Diesel would be the ultimate engine for you, if it ever gets into serial production.
http://www.regtech.com/16.html

[mars01]

There are plenty of gravestones out there associated with Lycoming. They aren't anything special when it comes to reliability, their only 'virtue' is that the degree of how unreliable they are is well documented.

I think you are misleading yourself.  If you look at the shear number of Lycs out there of course you are going to have failures.  I'd like to see total numbers of engines ever built and flown against number of failures.

I liked the link you had for the rotary stuff.  They looked cool.  I drive a 94 RX7 and love it.  It is a gass guzzler when I got the twin turbos working and it is like driving a Bike performance wise.

IMO ok so you have less moving parts in the engine iteself, but you are also adding a cooling system, which if you have the slightest of problems you are in trouble.  Then you have the gear drive assembly so are you really cutting down on moving parts and simplifying systems???

Personally, if I am going to put my family and friends in something I built I would want the engine to have a long history of proven service much like the lycs rather than just looking good on paper.

Sounds like fun, good luck

[Golfer]

When the engine takes a dump on you...are you going to say "well at least I saved money putting it in the airplane I and my family are in now!"

With the Lycoming...it's very likely you'll never have to say such things because an O-320/O-360 is as bulletproof a motor as you can find.  They're not good at being quiet when you want them to make noise.

[Chairboy]

The Lycoming mafia strikes again...  

This isn't about saving money, it's about not trusting my life and the life of my family to a Lycosaurus, 1930's technology that's been worshipped as infallible because if it costs $15,000 to overhaul, it's GOTTA be good.

Lycomings and Continental are old, inefficient, and fragile.  They're prone to shock cooling, burnt valves, thrown rods, and they come apart all the time.  Getting one to TBO is a chore, they vibrate like you're being towed through the air by a herd of elephants, and when they fail, they fail catastrophically.  

A rotary might not be perfect, but when it fails, it usually continues to generate reduced power (making it easier to get to a landing spot).  Just about all engine outs on rotary powered planes have been accessories, not the engine itself.  There are hundreds of people developing the solid rotary setup, and I have years before I buy a powerplant to watch and learn.

The only advantage a Lycoming gives me is that it's easier to just bolt on and fly, but I'm not satisfied with the level of reliability, failure modes, or design of the engine, so I'm adding a bunch of time to do an engine test regime with a rotary.  

Something to think about, there are more hours on wankel rotary engines than there are on Lycomings, and they are produced on a much larger scale and are constantly being improved.  It's a proven engine, just not proven on aircraft yet.

[Casca]

Good luck on your project!  Sounds like a fun ride.

I agree with you on Lycoming technology.  It is ancient and obsolete.

The O235 L2C, O320 and O360 parrallel valve models however are extremely reliable and routinely reach TBO.  I think you are overstating their weaknesses.

The fact that "Its a proven engine, just not proven on aircraft yet." means that it is unproven in your anticipated application.  The problem with any automotive adaptation to this point is that the old creaky Lyc is designed to operate at and routinely operates at up to 75% of rated power and most automotive engines are not and do not.

You might turn out to be correct.  It might be the smoothest and most reliable setup since the P&W PT6 series.  If it were my airplane and family though I'd stick with the devil I know instead of the devil I don't.  

You say the only advantage to a Lycoming is ease of installation.  I can think of two more:  A constant speed prop (which would be way nice), and probably better resale value if it ever winds up in Trade-A Plane.

I wish you great luck with this project and the conversion.

Don (Casca) Corleone

[Chairboy]

You can install a CS prop on a rotary, and I'm considering one.  If I do, I'll propably use an electric instead of hydraulic CS prop, it depends on the state of the industry when I get there.

As for resale, I'm building the plane for ME, not for the next guy who might own it.    A plane like this could be something I own for the rest of my life (I know that opens up some great joke opportunities, heh).  I doubt the decrease in resale would be the entire amount of the engine, but if so, meh.  Like I said, I don't like Lycomings.

Another nice thing about the Rotary: I can rebuild it myself in a couple hours with a $1.99 socket set.  It's simple, bulletproof, and easy to work on.  Who could ask for anything more?

[LePaul]

That turboprop article was a good read, I wonder what kind of economy he's getting

[Golfer]

Lycoming motors may be 1930's technology...but they work.

My post a few posts up and Casca mention the O320, O360 and O235 as found on the C-152.

These motors are as bullet proof as they come and the only ones that I've ever seen not make TBO are ones not maintained with regular oil changes at the 50 hr mark (or 90 days).

Looking at engine trouble I've blown a cylinder on an O-200 (continental) in a C-150.

I've had a rough running O-320 whicih turned out to be a bad set of piston rings from the overhaul (non factory) at less than 20 hrs after the engine change.

O-320 oil return line clamp was loose resulting in oil contacting hot engine parts making some smoke.  Shut down motor and returned to land.  A few turns of a hose clamp socket later the airplane was good to go.


That's a pretty short list for 1400 hours of Lycoming time in many different makes/models of varying maint. status.

The O-200 in the 150 was used/abused flight school airplane worked too hard.

The piston rings hang squarely on the shop.

The oil return hose is no big deal.



As far as

Who could ask for anything more?

I'll fly my family behind proven technology.  If there was something that much better...wouldn't they be using it?  It's old...but proven.

[Chairboy]

Originally posted by Golfer
If there was something that much better...wouldn't they be using it?

Bestest argument evar.  I'll call up the patent office, won't be needing them anymore!  While I'm doing that, you can get on the phone to the companies with R&D organizations with the good news that they can all close up shop.

On a more serious note, aircraft piston engine development basically stopped after the introduction of the turbine.  The piston GA market is too small to fund technology improvements, and the military dollars went towards jets.  Automotive engine development has continued because there's so much money in it, but there just isn't enough demand for anywhere near the same level of research for small planes.

Compare the quality requirements for modern auto engines against 'factory new specs' for a Lycoming someday.  You'll be convinced that someone misplaced a decimal point...  but they didn't.

The rotary isn't proven in small planes yet, but there are a few million of them out there in cars and other areas, and they're doing fine and getting better every day.  The last time the Lycoming got better, we were in the middle of the New Deal.  

[Ghosth]

Don't a lot of ultralights have small rotary engines in them?

As for myself, dad had 2 snowmobiles same model, 1 had 15 hp piston engine.
Other had 15 hp rotary engine.

None of us kids could start the piston job, but we could all easily start the other one.

So guess which one we beat the living crap out of?

It never did die, got so it smoked a bit more, drank a bit more oil. But it never did die.

Dad used the other one for fishing for years. Pulled amazingly large fishing houses through 3 ' unbroken snow,  that crazy snocat thought it was a bulldozer. Right up till the day it blew.

Stick to your guns & good luck chair!

[capt. apathy]

don't rotary engines get weird torque issues with the engine working like a make-shift gyroscope when you try to maneuver?

seems like I heard something about it on WW1 planes.  maybe newer engines don't have the same problem.