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Still young, but ol'time RV guy; project needed.

BruceMe

BruceMe

Well Known Member
I purchased my first RV (-3A) in 1996. I was a fresh 100hr pilot with a whopping 10hrs on wet-ink tailwheel endorsement. My story goes just fine (and it's an interesting one, I'll tell it again if you want) but I don't think it's for just anyone.

[..back to my post]

I purchased a wing-spar to an RV-4 in 1997 thinking I'd build it some day. Well, that day came and I sold the RV-3 to buy the engine and last few -4 kits and in 2008 I had an airworthiness and a a flying RV-4. This spring (2015) I can actually say its "done". And well... it costs a lot more than I can really afford ($40k) and my kids are heading off to college and perhaps I'm turning that page where I actually miss building (OMG! did I say that)

I need something to keep me out of trouble and I really miss my old RV-3. What about a scratch build? I'm thinking hummel bird or back-to-basics mostly scratch built RV-3B (O-235 powered, hand prop).

Can you even do this anymore? Vans doesn't price a full plan set anymore, just preview plans. Anyone?
 
BruceMe said:
I need something to keep me out of trouble and I really miss my old RV-3. What about a scratch build? I'm thinking hummel bird or back-to-basics mostly scratch built RV-3B (O-235 powered, hand prop).
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I flew Hummelbird a few weeks ago - fun little airplane, and yes - pretty simple to build from plans or with a parts kit. Nowhere near the performance of a -3, but very inexpensive and fun.

RV-3, Panther,Hummel - the choice is mostly the kind of performance and handling you want as a flier. If you are just interested in a build, I think the Panther is no doubt the easiest, the Hummel and RV-3 will be pleasant challenges, and the Hummel will build faster because it is smaller and pulled-rivet.
 
Thanks,

I am very interested in your opinion on the flying quality of the HB. I'm starting to become one of those "sunny-day" pilots that just like to get up in the air and look around, then come back down in 30 minutes or an hour. I think any of these planes will suffice for that mission.

Is the HB well balanced? Is it too positive? Are the controls sluggish? I suspect the answer is no... but not RV-3 fast. Right? I'm still leaning toward building the lightest and simplest RV-3 since Van himself modified a playboy.

.. btw, this is exactly the feedback I wanted, anyone else?
 
How to engine? I know I have a long time. Just thinking

O-320 (140-160hp) - 260 lbs
O-235 (105-125hp) - 245 lbs
Corvair (80-120hp) - 210 lbs (estimated at 35lbs lighter than an O-235 from various sources saying it's 40-lbs lighter installed)
Jabiru 3300 (107-120) - 178 lbs

I tried really hard to make this apples to apples, all weights are dry-weight, no starter/accessories.


O-235 is the easy choice
Jabiru is the lightest, but costs the most
Corvair is compelling for cost/weight.

The Jabiru and Corvair are both 4" narrower, I could custom make a new narrow-cowl in the RV-8 style with lo-presti intakes. Has me thinking.

I'm also heavily influenced by Dave Anders' work on the CAFE champ RV-4. I'd like do his treatment to the engine cooling air exhaust and others.
 
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On the Onex, thanks again, I'll bookmark that one too. I like the folding wing. I've always felt Sonex (et al) where ugly. I have to get over that first.
 
BruceMe said:
On the Onex, thanks again, I'll bookmark that one too. I like the folding wing. I've always felt Sonex (et al) where ugly. I have to get over that first.
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The Panther has a very unique and easy folding wing. I remember Van himself checking it out a couple years ago at Sun 'n Fun, and commenting that it was very clever.

Shameless plugs for the Panther, since Dan Weseman, Panther designer and builder, is one of my best friends. He flies his boys in my -6 when he is not putting the Panther through it's paces, or shipping Panther kits.
 
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ccsmith51 said:
The Panther has a very unique and easy folding wing. I remember Van himself checking it out a could years ago at Sun'n Fun, and commenting that it was very clever.

Shameless plugs for the Panther, since Dan Weseman, Panther designer and builder, is one of my best friends. He flies his boys in my -6 when he is not putting the Panther through it's paces, or shipping Panther kits.
Click to expand...

Yeah, I liked the folding wing there too. Panther is a prime contender here.
 
BruceMe said:
Thanks,

I am very interested in your opinion on the flying quality of the HB. .......

Is the HB well balanced? Is it too positive? Are the controls sluggish? I suspect the answer is no... but not RV-3 fast. Right? I'm still leaning toward building the lightest and simplest RV-3 since Van himself modified a playboy.
Click to expand...

With half a VW engine, you will find that it doesn't climb very fast, and it isn't all that fast either. It is just .... unique! It is not in the same category as any of the other airplanes in this thread.
 
Ironflight said:
With half a VW engine, you will find that it doesn't climb very fast, and it isn't all that fast either. It is just .... unique! It is not in the same category as any of the other airplanes in this thread.
Click to expand...

The pilot who gave me 8 hours dual in the RV-6 built and has flown the Hummlebird, I've helped him launch and have seen it fly. The half VW has not been reliable, he's had at least 2 partial engine out landings. Problem with carb or vapor lock.

A local auto mechanic commented one day, why would anyone want to chop a good engine in half? :)
 
With the Jabiru, I think you'd want the starter. When it catches, which the one I've flown does instantly, it's immediately running a whole lot faster than I'd ever feel comfortable hand-propping.

I'd considered the O-235 but then a nice O-320 dropped into my hangar just in time for Christmas a couple years ago. Probably just as well, I like climb rate.

Dave
Building RV-3B, now hanging the flaps
 
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David Paule said:
With the Jabiru, I think you'd want the starter. When it catches, which the one I've flown does instantly, it's immediately running a whole lot faster than I'd ever feel comfortable hand-propping.
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From the manual;

Ground Idle Speed.......................... 900 RPM (set while engine is hot)

Manuals all have a... "your mileage may vary" disclaimer, but I suspect a light fine-pitched wood prop on a draggy plane which means an aggressively high RPM was fine and nobody bothered to tune it lower. Engines start so much nicer at 800 rpm. Just a nice thump thump thump... Anyway, I probably won't get a Jabiru regardless. $18k... I bought the first-run IO-320 in my RV-4 for 8k, replaced all accessories and it still runs great for far less than $18k. Yeah, I know it's not new.
 
Yeah...

David-aviator said:
he's had at least 2 partial engine out landings. Problem with carb or vapor lock.
Click to expand...

All part of the "fun" :confused:

I've been asking "silly" questions on the half v-dub forum like...

Can you fly a hummel-bird level on one cylinder, cause ignition failure happens?

And..

I don't see any induction heaters, what do you do when it's cold and damp?

The best answer so far is, don't fly. Which honestly is not an awful answer, just a limitation. Like flying into known structural icing. I don't do that either. But carb ice is a lot easier to forget on a beautiful cool dewy morning. As for vapor lock.. well, RVs have had more than their share in that department. Fire-sleeve and line placement/cooling are the only fixes.

I digress, the hummel just looks cute. If I don't really enjoy flying a 150, I probably won't enjoy flying an HB. I think the RV or Panther are the front runners still.
 
Ok,

Panther vs. RV-3... And correct me if I'm wrong here.

Just from looking at the parts, it's obvious the Panther is more precisely engineered. The critical spar and connectors are CAD/CNC'd. Pretty impressive really. The tube cockpit is structurally stronger and the fastback was a wise design decision as it improves performance and better protects the pilot when it roles over. The RV-3 has been know to injure and trap pilots in role over, hence the bar.

I do think a big part of the allure of all Vans aircraft is the flush solid rivets and it's worth putting the time into it. Faster, lighter, better for a 20% more time. What's a little more time futzing around dropping 4,000 tiny -3 rivet into a tiny #40 whole.

The Panther landing gear are far superior to the RV-3/4 rounded dowl hippity-hoppity sticks. Big plus there!

One small aerodynamic gripe is the wing-fuselage intersection. If you look at an RV-3/4,etc, you'll see they match up quite neatly and the the majority of the wing bottom skin forms one unbroken surface through the fuselage to the other wing bottom. What that means is that the RV's only have two areas wing-fuselage interference drag above each wing-half. Whereas the Panther will have four regions, one above and one below each wing-half.

Also the bottom area of the fuselage behind the engine mount looks boxy and awkward. The RV's have that area really tidy, it all blends together and in the RV 3/4 that low spot under the spar joint is one of the few areas with a very mild multi-curve (you have to seem it up the middle) and it's a real pain to build.

There is no doubt in my mind the Panther costs more. I'd have to lay it all out, but I'd be shocked if it didn't come out to about 5-8k more for the ready-to-fly airframe. I also suspect the performance and weight are strikingly similar to a similarly powered RV-3. They're just too similar to not be.

I do have one last thing to hand to the Panther and a nod to Vans... The RV-3 is a 44yo kit still enthusiastically being built because of it's outstanding value. The Panther is easily the closest total-performance design to the RV-3 I've seen to date. I suspect that with modest refinements, it could decisively overtake the RV-3 in this department some day. That would be a monumental aviation feat!

-Bruce
 
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BruceMe said:
All part of the "fun" :confused:

I've been asking "silly" questions on the half v-dub forum like...

Can you fly a hummel-bird level on one cylinder, cause ignition failure happens?

And..

I don't see any induction heaters, what do you do when it's cold and damp?

The best answer so far is, don't fly. Which honestly is not an awful answer, just a limitation. Like flying into known structural icing. I don't do that either. But carb ice is a lot easier to forget on a beautiful cool dewy morning. As for vapor lock.. well, RVs have had more than their share in that department. Fire-sleeve and line placement/cooling are the only fixes.

I digress, the hummel just looks cute. If I don't really enjoy flying a 150, I probably won't enjoy flying an HB. I think the RV or Panther are the front runners still.
Click to expand...

Truth is, the best answer is don't fly it...and that's what's happened with the local HB. :)
 
David-aviator said:
The pilot who gave me 8 hours dual in the RV-6 built and has flown the Hummlebird, I've helped him launch and have seen it fly. The half VW has not been reliable, he's had at least 2 partial engine out landings. Problem with carb or vapor lock.

A local auto mechanic commented one day, why would anyone want to chop a good engine in half? :)
Click to expand...

I flew my Legal Eagle with a Hummel Engines 1/2 VW for four years. This was the 45hp version built by Scott Casler and I found the engine to be 100% reliable.

Casler builds a carb heater/oil cooler on the intake manifold which eliminates carb icing. The single ignition is still a factor but mine had a Slick mag which never gave any issues.

Why cut a VW in half? Because that is a good way to get a reliable four stroke engine that is suitable for an aircraft that weighs less than 300 lbs.

I found the 1/2 VW to be a cool little engine that sounds neat and was fun to fly. It is now on its second owner who flies it even more than I did.

http://eaglexl-58.com
 
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Sam Buchanan said:
I flew my Legal Eagle with a Hummel Engines 1/2 VW for four years. This was the 45hp version built by Scott Casler and I found the engine to be 100% reliable.
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There's a class of "hangar-queen" experimental homebuilt that the 1/2 V-Dub is frequently bolted to. I think like anything, close attention to detail and craftsmanship are the deciding factors for general reliability in practical application. FYI... this absolutely applies to RVs too. Every single engine issue I've had was because of something I did wrong as the builder. It's been years now, they are all fixed and long gone, but at the time you think you're chasing gremlins.

Thanks Sam, good info.
 
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Corvair engine choice

The Corvair is a good engine but short stroke which means it will not have the climb performance as a longer stroke Lycoming.
In my opinion the Corvair needs to have a front bearing to support the propeller pulling and vertical loads to save the crankshaft from bending loads, there has been several broken crankshafts in engines without the propeller support bearing. You can see my hub in this video, it's homemade and I don't where you would be able to purchase such a thing. I would not fly a Corvair engine without some sort of propeller support bearing.
https://youtu.be/Mwx8zfeifGQ
 
RV-3 Kit

Bruce,

There is guy named Rod Woodard who has an RV-3B kit (complete except the finsihing kit) that he's been trying to sell for a while. It would save you a bunch of time and money on an RV-3B build, instead of going the "plans only route..." I think his last post in the classifieds asked for $8,000, which is a few thousand under what Vans asks. This way, you'd get a new 3B to build with a lot of the material prep and sourcing already done (vs. plans only).
 
ppilotmike said:
Bruce,

There is guy named Rod Woodard who has an RV-3B kit (complete except the finsihing kit) that he's been trying to sell for a while. It would save you a bunch of time and money on an RV-3B build, instead of going the "plans only route..." I think his last post in the classifieds asked for $8,000, which is a few thousand under what Vans asks. This way, you'd get a new 3B to build with a lot of the material prep and sourcing already done (vs. plans only).
Click to expand...

That has been sold. http://www.vansairforce.com/community/showthread.php?t=131083
 
You got me all excited! I have a line on an O-235 too. I thought I was 10 grand away from paradise for a few minutes.
 
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