Can you install an RV-8 Vert fin and Rudder on an RV-6?

[Denman]

I am starting a 6 project with the old style fin and rudder. It was suggested that I may want to sell the old one and look to put on the 8 verticle fin and rudder instead.

Anyone have any experience with this, or heard if the swap can be done?

I do know that 6's used to have the 8 tail, but I'm not sure if there were any other changes to the empanage or fuselage?

 

[smokyray]

The answer is...

I am starting a 6 project with the old style fin and rudder. It was suggested that I may want to sell the old one and look to put on the 8 verticle fin and rudder instead.

Anyone have any experience with this, or heard if the swap can be done?

I do know that 6's used to have the 8 tail, but I'm not sure if there were any other changes to the empanage or fuselage?

Short answer: Yes you can.
However, I have flown 2 "Big tail" RV-6's, one with an RV7 and one with an RV8 vertical tail. The big tail 6's were a tad bit more "stiff" in the rudder compared to stock. The only advantage I see is the 7 and 8 rudders are counterbalanced. My advice is to mount the stock Six Vertical Stab. Why? It flies great, costs you less and looks less "gangly" in my humble opinion.


FYI: My "RVX" is a Six fuselage with RV4 empenage (The stock 6 and 4 share the same VS) It flies very well, better balanced in all axis than most RV's I have flown.

V/R
Smokey

You be the judge:



RVX with stock RV4/6 VS





RV-6A with RV-7 VS (and label)

 

[L.Adamson]

The shorter 6 tail, was given the name "classic", by someone from this forum. I think it fits perfectly! The classic tail just looks better!
My plane has one, and I prefer it.

L.Adamson

 

[n5lp]

The shorter 6 tail, was given the name "classic", by someone from this forum...

I think that was Mel. I agree also. Looks right, works well.

 

[jsharkey]

My -6 has a -8/early -7 tail and the rudder does seem "stiff" - especially forward slipping to land in a crosswind - but I have never flown a "classic" -6. I assumed that all RVs were like that.

Jim Sharkey

Short answer: Yes you can.
However, I have flown 2 "Big tail" RV-6's, one with an RV7 and one with an RV8 vertical tail. The big tail 6's were a tad bit more "stiff" in the rudder compared to stock. The only advantage I see is the 7 and 8 rudders are counterbalanced. My advice is to mount the stock Six Vertical Stab. Why? It flies great, costs you less and looks less "gangly" in my humble opinion.


FYI: My "RVX" is a Six fuselage with RV4 empenage (The stock 6 and 4 share the same VS) It flies very well, better balanced in all axis than most RV's I have flown.

V/R
Smokey

You be the judge:

 

[rvmills]

Dennis,

I swapped my classic 6 tail for an 8 tail last year. My reason was to add the counterbalance for racing speeds. In talking with Van's staff, sounds like some later 6 kits actually came with an 8 tail, so its a straight forward swap, if you decide to go that way. My experience was that it was a simple change, and even my tail fairing fit the new VS pretty well.

As far as performance changes go, I think it slowed me a knot or two (perhaps due to the 5" taller tail), and I actually feel like I need a tad more right rudder than before (still can't quite figure that...thought it would be the opposite, and neither had/has fixed tabs). As for being stiffer...maybe...a little...but my 6 is heavier and longer than stock anyway...and I'd not doubt my pal Smokey on that assessment. It does feel a little lighter than the 7's I've flown, FWIW.

I really like the classic tail looks too...but I'd never call my new tail gangly! Truth be told, I wish I'd done what Dave Anders did on his 4 and Greg Nelson did on his F1 Rocket: Build a 4 or 6 tail with a rudder counterbalance engineered and built in! Classic look, good speed, and counterbalance ta-boot! A fair bit of work though!

Here's some pics for comparison:

Before:

During:

After:

Before:

After:

Does that make the call any easier?

Cheers,
Bob

 

[jimbower]

New tail looks good to me...

I got my -6A empennage kit in 2000, containing the -8 VS and rudder. The buzz at the time was that Van's had included the bigger tail because people were putting bigger engines in their -6s and the VS helped counteract the torque and worked better at higher speed. If your engine is more than the "standard" 160 hp, you might consider using the larger tail. Otherwise, go with the one that pleases you.

As for looks, I think the "classic" tail looks fine on the taildraggers, but the new tail looks better on the nosewheel versions. Just my opinion. I don't really notice much difference in the rudder (I have 8.3 hours in "Old Blue" and about 50 hours on mine).

 

[sailvi767]

[/IMG]My Six which was built by Robbie Attaway has the small tail with a balanced rudder. I love the looks and handling of the aircraft. Robbie tested it to some pretty high speeds for flutter. I also think that the smaller tail makes the transition period around 30 knots easier in a crosswind. I think the bigger tail can have a bit of a barn door effect. Thats a purely subjective opinion however.

George
RV6

 

[sailvi767]

Here is closeup of the rudder.

George

 

[L.Adamson]

I got my -6A empennage kit in 2000, containing the -8 VS and rudder. The buzz at the time was that Van's had included the bigger tail because people were putting bigger engines in their -6s and the VS helped counteract the torque and worked better at higher speed. If your engine is more than the "standard" 160 hp, you might consider using the larger tail. Otherwise, go with the one that pleases you.

As for looks, I think the "classic" tail looks fine on the taildraggers, but the new tail looks better on the nosewheel versions. Just my opinion. I don't really notice much difference in the rudder (I have 8.3 hours in "Old Blue" and about 50 hours on mine).

For all of these years, at least since 1994, I've always figured that the standard engine for an RV6.............is 180 HP. Never heard about this "torque" thing, and more just about the new tail being a standardization of kit parts, as the "8" evolved.

L.Adamson

 

[jimbower]

Actually, the "standard" engine for the -6 was the O-320 (either the 150 or 160 hp flavor). I seem to remember that when I got my emp. kit people were using the O-360 (180 and 200 hp) more and more. There had been problems with the smaller tail. That's just what I heard, but hey...it was 12 years ago and I could have forgotten the details. I just built the kit as it was delivered and I'm happy with its looks.

 

[RV6_flyer]

Actually, the "standard" engine for the -6 was the O-320 (either the 150 or 160 hp flavor). I seem to remember that when I got my emp. kit people were using the O-360 (180 and 200 hp) more and more. There had been problems with the smaller tail. That's just what I heard, but hey...it was 12 years ago and I could have forgotten the details. I just built the kit as it was delivered and I'm happy with its looks.

There was NO control problem with the smaller tail. There was an issue with guys that were putting 360's on the RV-6 that would get cracks from the extra strong power pulses in the rudder and elevators. They were originally 0.016 and that many of the guys that used 360's developed cracks. 0.020 skins were used to replace the 0.016 skins on my of the ones that cracked.

My 320 developed a crack in the 0.016 rudder around 2,000 hours. I rebuilt both elevators with 0.020 when I had a helper helping push the airplane into my hangar. Needless to say, the hangar won and the elevator lost.

 

[Maurice Dubois]

I have a 6 with an 8 tail & engine - love it

My first RV-6 had the small tail and rudder and the 180 hp engine; flew it for 2 years. In 2003 I stepped up to an RV-6 with an 8 tail and rudder and the injected 200 hp Lycoming. I love the plane; way better than the old one; climbs better, is a little faster and handles better.

A few months ago I took off with a strong, direct cross wind; nobody else was flying for the wind. It took it in stride.

 

[L.Adamson]

My first RV-6 had the small tail and rudder and the 180 hp engine; flew it for 2 years. In 2003 I stepped up to an RV-6 with an 8 tail and rudder and the injected 200 hp Lycoming. I love the plane; way better than the old one; climbs better, is a little faster and handles better.

A few months ago I took off with a strong, direct cross wind; nobody else was flying for the wind. It took it in stride.

I've heard it two ways. The larger rudder handles crosswinds easier, while the crosswinds also effectively push sideways on the larger surface more. Having the smaller rudder, I've never known for sure.

 

[rvbuilder2002]

Just my opinion. I don't really notice much difference in the rudder (I have 8.3 hours in "Old Blue" and about 50 hours on mine).

Just FYI.... old blue has had the bigger tail since about 1998, when it was installed to do flight testing before making the change to RV-6 kits.

Actually, the "standard" engine for the -6 was the O-320 (either the 150 or 160 hp flavor). I seem to remember that when I got my emp. kit people were using the O-360 (180 and 200 hp) more and more. There had been problems with the smaller tail. That's just what I heard, but hey...it was 12 years ago and I could have forgotten the details. I just built the kit as it was delivered and I'm happy with its looks.

As has already been said, the change to the RV-8 vertical and rudder was for parts commonality only, for the production and cost reduction efficiency bennefits.
There was (and still is) nothing wrong with the classic tail.
The taller tail does seem to require a little bit more rudder input (primarily at low speed during the take-off roll in my opinion), that I think is caused by a larger surface area for the prop spiral to have influence on.

 

[Denman]

Hi All:

Thanks for all the replys. The reason I was thinking of it was due to the hunting of the smaller tailed 6s during cross country and for better spin characteristics. Not that I am planning of spinning it.

I have flown both the 7 and the 6. I agree with the lighter feel of the 6 over the 7, yet the 7 feels more solid while straight and level.

There are benifits to both, and right now the one that made most sense was it's cheaper, and I won't have to look for or order a new tail That and you can never go wrong with a "classic look"

Dennis

 

[n5lp]

I seem to remember from the time that it was thought that the larger tail might help with the somewhat exciting spin characteristics of the RV-6, when spun for more than a few revolutions. It is also my recollection that it was determined that the tail change didn't affect the spin characteristics very much.