Monnett Aero-Vee conversion system

[Aviacs]

Was the Super Vee extension unit unpopular because it required machining?
Was it unreliable in any way?
Or did it fail to keep up with the HP as VW engines got bigger from the original 1700's?
How does it compare with "modern" extended crank front drive systems?
Does anyone still run one?

The engine in my S2L is a GP 2276.
The above Q is for comparison/personal enlightenment.
The unit seemed to be the hot ticket in the 70's. Now that i am back to Sonerais, they are nowhere to be seen.

smt

 

[soneraii]

My neighbor flies behind a Super Vee extension and has for about 45 years and 1350 hrs. No problems.

From an simplicity standpoint the GPAS Force One crank is simpler, very reliable also. Available.

I run a Force One and about a two inch extension...works great, gets the prop and spinner out there where I needed it.

Kevin

 

[Aviacs]

Thank you, Kevin - that is good to know.
Now i wonder if the Aero-Vee case extension might support more complex prop systems, E.g. ground adjustable (with wooden blades); or even a simple 2 position prop.

smt

 

[[email protected]]

the aero-vee extension is not safe to fly behind. check older news letters. cracks from keyway and threads cut were common failure points.

 

[Aviacs]

the aero-vee extension is not safe to fly behind. check older news letters. cracks from keyway and threads cut were common failure points.

Interesting.
Using search terms "Aero Vee" and permutations including "Aero-Vee" etc; as well as "Engine extension" and some others only returned to my original post, this thread.

I have all the old newsletters from Fred and lost 2 days initially to browsing them (well, i had a newly broken finger/messed up hand at the same time anyway.) Nothing about extensions at all jumped out at me. Will have to check again but am now busy trying to catch up on work.

Also, it sounds like a stock crank issue, more than an Aero-Vee issue?

smt

 

[soneraifred]

The original Monnett engine conversion with the cast prop hub housing was called “SuperVee”. When the SuperVee was discontinued due to cost issues, the replacement press-on prop hub was called “EconoVee”.

 

[Aviacs]

They were both offered at the same time through the 70's. I have some catalogs from that period.
in '78 the "Super Vee propeller extension unit" cost $230 complete with all parts. The "E-Cono_Vee propeller hub unit" cost $75.

Searching with key word(s) Super Vee and permutations only returns to this post or shows no listings.

smt

 

[Aviacs]

Short Bus said:

the aero-vee extension is not safe to fly behind. check older news letters. cracks from keyway and threads cut were common failure points.

Well I tried to catch up on work too soon for my broken finger. Or maybe it was the time i stood up in the office and inadvertently hooked the splint under the arm of a metal armchair, nearly pulling that finger off and throwing me to the floor. At check-up this week, the bones are now partially overlapped & they want to commit surgery.

To the point of Sonerais, it has enforced more spells of reading the old newsletters.

I've done a pretty thorough read thru 1995 (first set) and saw one split (cracked) EV hub, a couple mentions about torquing issues with the taper nose cranks, and -0- of any relevance about the super-vee extensions. I will continue to slog through the second set (which was already skimmed on arrival). However, perhaps you can give me some pointers or mention a topic the extensions might have come up under.

Thanks!
smt

 

[Aviacs]

I've now read all of the old newsletters as provided by Fred.
Loads of useful information for small but important improvements to the AC at the point it is here and i can pursue the US airworthiness cert. Lots of info on things that will add to longevity for the engine. (Many of the airframe and engine items may already be completed - but now i know what and where to inspect for them.

However, re: the genesis of this thread, there may have been 3 mentions of the super-vee extension, but no substative information or pro-con discussion whatsoever.

Reading that, and looking at the GP catalogs that came with the AC paperwork piques another curiosity, however - what ever happened to the GP rear- drive extension project? (With the projection casting, bearings, damper, and quill shaft?)

I have searched this website re the Super-Vee extension as far as likely terms occurred to me. I have not yet searched re: the GP rear-drive-with-extension project.

smt

 

[Flyguyeddy]

Great plains does sell a rear drive hub and extension setup if you wish to go that way. Others have done so with success

 

[Aviacs]

Yes, but the current de-volution to merely a hub, does not appear to offer the use of "more complex" propeller systems than a simple wood fixed pitch.

Steve Bennett's rear hub extension casting with bearings and quill shaft were expressly marketed as "can use non-wood propellers". I don't think the original super-vee, which added the projection casting and bearings onto the front end, was marketed quite that ambitiously. But it could use ground adjustables. My original Q was curiosity about whether people may have used composite props on them with any success.

My history (such as it is) with Sonerai's is as follows.
Bought S2 plans set #225 in 1975.
Attended John Monnett's builder school/long weekend seminar/Stout affiliated class in '76.
Somewhere in that period (mid- 70's) *Bob Aymar's Continental 65 S1 quit shortly after take-off, leading to pancaking into a berm off the end of the runway at FDK. He "sold" me the remains, sans engine. (For the price, essentially, he gave it to me). Being young and having started a construction business, i did not progress. One of my kid brothers made the classic observation "do you want to build or do you want to fly?" Ideally, both. However in the late 80's we bought a C175 together and i completed my license. 25 years ago i started a family and moved to upstate NY. Got TW endorsement & became involved in incorporating a flying club that operates C140. Added a pre-war J3 Cub with 65HP continental. Finally, this year in March, bought (the former) G-PXD.

Having spent a few hundred happy hours behind a geared engine-prop combo I have to say the concept just feels ideal to me. So much efficiency for the weight & fuel burn. The record shows that Steve Bennett was working in that direction when sadly, he passed on. (actual gear reduction drive, apparently within the extension nose casting; besides the belt drives)

There's a lot of "free" extra thrust in a VW engine at a given HP, if it could either swing a controllable prop to optimize climb and cruise (optimize rpm and MP at both extremes), or if it is geared for reduction to swing a longer propeller more slowly.

The solution to a geared system is beyond me. (I could machine it but can't design it)
A controllable prop seems possible. Possibly the super-vee casting assembly, or certainly the Bennett/GP rear drive casting as advertised should support one. But there is very little information out there. The systems exist. I thought there would be more actual experience with one or the other on the Sonerai home site.

If this aggravates people, I'll pipe down about it.

smt

*Bob Aymar was something of an idol who made a point of extending his personal friendship. He was obviously quite a bit older than me; so i was more than polite in my inquisitiveness at the time. Memory is that he was a hydrological engineer, or at least worked in that field. He sometimes explained what he was working on (cavitation). He did work on ships' screws. I "think" he started making airplane props when one was needed for the S1. I remember when the gunstock lathe was started to reproduce them, but never saw it finished. He spent a lot of time explaining the workings of things like that to me. Much of what he taught me extended to ways of thinking and other fields of making, less so directly to aircraft.

 

[Chucker]

The Revmaster engine was designed for a controllable pitch propellor. My 2100D still has the plumbing for controlling a prop with oil pressure.

I am told that the Revmaster crankshaft and prop flange/bearing had no problem with the increased mass. Unfortunately, they never found a propellor hub that would stay together. Call Joe Horvath at Revmaster. He is a wealth of information and walked the same path as Steve Bennett through the evolution of flying VW engines.

ATB,
Chucker

 

[smokyray]

MT makes an electrically controlled CS prop for the Rotax 912 that could be adapted to the VW flange bolt pattern fairly easily.
Additionally Sauer Engines in Germany manufactures a Certified (In Europe) VW derivative engine used in several LSA type aircraft including the Groppo Trail and corresponding composite props. They list several CS prop applications for their engines as well...

FYI 8)

http://www.sauer-flugmotorenbau.de/Propeller.html

V/R
Smokey