Van's Air Force
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RV-8A to RV-8 conversion
- Thread starter denbobp
- Start date
my dimes worth
Hi Denbob, I am building an RV8 and from the construction experience I know that the area immediatley around the landing gear is strongly reinforced with structures not seen on the 8A....e.g there is the landing gear towers and weldments to take the stress forces on landing and spread it throughout the immediate fuselage area. In my opinion only, it would be a major undertaking....
Now that I have posted a reply maybe other builders will join in to give their advice. Good luck
Hi Denbob, I am building an RV8 and from the construction experience I know that the area immediatley around the landing gear is strongly reinforced with structures not seen on the 8A....e.g there is the landing gear towers and weldments to take the stress forces on landing and spread it throughout the immediate fuselage area. In my opinion only, it would be a major undertaking....
Now that I have posted a reply maybe other builders will join in to give their advice. Good luck
Andy Hill
Well Known Member
Review Section 4 (Parts Index) against the plans and try to annotate type specific parts (both 8A and 8). The Drawings are sometimes labelled RV-8A or RV-8, but I found that somewhat unreliable i.e. even an RV-8 sometimes had sections on the RV-8A pages you needed.
Might be worth asking Vans to send the "parts lists" for the 8 and 8A Fus kits, and then manually compare them?
Finally, as you do build up a definitive list, it might be worth filing it somewhere on line / referenced from here for others with the same issue in future?
Andy & Ellie Hill
RV-8 G-HILZ
RV-8tors
Might be worth asking Vans to send the "parts lists" for the 8 and 8A Fus kits, and then manually compare them?
Finally, as you do build up a definitive list, it might be worth filing it somewhere on line / referenced from here for others with the same issue in future?
Andy & Ellie Hill
RV-8 G-HILZ
RV-8tors
denbobp
Well Known Member
parts list available (any request?)
I was sent a parts list and it it has listed 58 parts that need changed unless some of the parts are used on both models. I am going through them now to see if there are any matches on the parts list at a cost of 2185.00. Looks major from first glance alright.
I was sent a parts list and it it has listed 58 parts that need changed unless some of the parts are used on both models. I am going through them now to see if there are any matches on the parts list at a cost of 2185.00. Looks major from first glance alright.
Danny King
Well Known Member
RV-8A to 8
There is no easy way to do this, but I was thinking that it could be done with a modified engine mount, and F-1 Rocket gear legs. The only modification to the 8A would be to install the tailwheel bulkheads, tailwheel spring mount, and wheel assembly. Then fit the cowling around the gear legs. New upper intersection and gear leg fairings would then have to be built. There may be issues with the existing exhaust system, but that would be manageable.
You would end up with a special looking RV-8 with racy F-1 Rocket gear.
There is no easy way to do this, but I was thinking that it could be done with a modified engine mount, and F-1 Rocket gear legs. The only modification to the 8A would be to install the tailwheel bulkheads, tailwheel spring mount, and wheel assembly. Then fit the cowling around the gear legs. New upper intersection and gear leg fairings would then have to be built. There may be issues with the existing exhaust system, but that would be manageable.
You would end up with a special looking RV-8 with racy F-1 Rocket gear.
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Danny King
Well Known Member
Motor mount mounted gear
Your drawing is good, but the main wheel axels would be right at the leading edge of the wing.
The motor mount would transfer the load to the longerons and into the fuselage structure. The RV-3, 4, 6, 7, and 9 all use the motor mount to hold the gear legs. The F-1 Rocket came from the Harmon Rocket II which was a modified RV-4. I was told that Van used gear towers because he felt that the swept of the gear would be too much with the 8's forward cargo compartment. I believe the F-1 Rocket uses very strong and light titanium gear legs to handle the load of the I0540, and they would work on the RV-8 with the lighter four cylinder engines.
Your drawing is good, but the main wheel axels would be right at the leading edge of the wing.
The motor mount would transfer the load to the longerons and into the fuselage structure. The RV-3, 4, 6, 7, and 9 all use the motor mount to hold the gear legs. The F-1 Rocket came from the Harmon Rocket II which was a modified RV-4. I was told that Van used gear towers because he felt that the swept of the gear would be too much with the 8's forward cargo compartment. I believe the F-1 Rocket uses very strong and light titanium gear legs to handle the load of the I0540, and they would work on the RV-8 with the lighter four cylinder engines.
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Wing mounted gear? Add retract too.
I wonder if the motor mount gear legs would have lower aerodynamic drag than the flat spring gear on our stock RV-8s? The intersection drag of the upper gear leg near the leading edge of the wing and all that?
So it might be a good idea.
I always thought mounting the gear to the wing spar, like a Radial Rocket would give a wider tread, better landing and less drag. Look cool too.
As a mod to an RV-8A, you wouldn't have to change the engine mount, or anything in the fuselage, fire wall or cowl. The redesign would all be in the wings with structure added inside the envelope, The hard work being the design.
I did see a local RV-4 with 200 Horse IO-360 and retracts. I belive the fuel tanks were moved outboard, and the inboard leading edge of the wing was angled forward to make room for the tire in retraction. (ahead of the spar)
An RV-8A would be a good start kit for a retract. What would you call that? An RV-8R
But I just stayed with the original plans so I could actually get 'er done!
I wonder if the motor mount gear legs would have lower aerodynamic drag than the flat spring gear on our stock RV-8s? The intersection drag of the upper gear leg near the leading edge of the wing and all that?
So it might be a good idea.
I always thought mounting the gear to the wing spar, like a Radial Rocket would give a wider tread, better landing and less drag. Look cool too.
As a mod to an RV-8A, you wouldn't have to change the engine mount, or anything in the fuselage, fire wall or cowl. The redesign would all be in the wings with structure added inside the envelope, The hard work being the design.
I did see a local RV-4 with 200 Horse IO-360 and retracts. I belive the fuel tanks were moved outboard, and the inboard leading edge of the wing was angled forward to make room for the tire in retraction. (ahead of the spar)
An RV-8A would be a good start kit for a retract. What would you call that? An RV-8R
But I just stayed with the original plans so I could actually get 'er done!
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Junglepilot
Well Known Member
Conversion...been there done that
I think I already PM'd you from an email.
I've done it and is all a matter of where you are. If you are converting a flying 8A to 8, I'd say forget it.
However if you are going from a partially built project that's a horse of a different color. But still depends on where you're at.
I worked closely with Vans engineering guru Ken Krueger on mine and came up with a parts list. About $1700 or so.
I decided not to use the 8A mount as the 8 has somewhat of a forward CG issue any how. So I had to get a new mount $600.
As far as the rea bulkheads, they are the same (F-811 & 812) However getting the tailwheel weldment in place is kind of a booger. Also documented on my site. But it is do-able.
My website has a lot of what I went through. (www.Junglepilot.org) However due to other pressing business I have not been able to update much of the work past few months even though work is moving ahead quickly (in the midst of wiring and hanging engine).
Anyway all this to say, I have re-built quite a few damaged taildraggers while with MAF and this was easier with the pre-punched parts etc.
It can be done and it ain't rocket science.
Sandy
I think I already PM'd you from an email.
I've done it and is all a matter of where you are. If you are converting a flying 8A to 8, I'd say forget it.
However if you are going from a partially built project that's a horse of a different color. But still depends on where you're at.
I worked closely with Vans engineering guru Ken Krueger on mine and came up with a parts list. About $1700 or so.
I decided not to use the 8A mount as the 8 has somewhat of a forward CG issue any how. So I had to get a new mount $600.
As far as the rea bulkheads, they are the same (F-811 & 812) However getting the tailwheel weldment in place is kind of a booger. Also documented on my site. But it is do-able.
My website has a lot of what I went through. (www.Junglepilot.org) However due to other pressing business I have not been able to update much of the work past few months even though work is moving ahead quickly (in the midst of wiring and hanging engine).
Anyway all this to say, I have re-built quite a few damaged taildraggers while with MAF and this was easier with the pre-punched parts etc.
It can be done and it ain't rocket science.
Sandy
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