Another Radial RV-8R

[VA Maule]

Gear wrap up

Pictures of the outboard stiffing / load transfer brackets ,left forward, right aft after match drilling to reconfigured U-803 brackets with 4 - 7/16” Allen head cap screws , see post 37 for a comparison between mine and the standard kit version. Picture of the reconfigured U-803 and wear plate all charred by the heat treating process. Picture of the 0.071 cover plate replacing cover plates F-861’s and the removed section of skin from F-850-1. Picture of the gear center section complete filling the area between the F-802 cross members.

 

[VA Maule]

Little inspiration

Ron I enjoyed our visits when you came to the competitions held in Farmville, I wish they were still having them. Here’s a picture for you and Steve. Steve will be interested in the relationship between the inner and forward cowlings, but Ron take a look at the outta date calendar over the tool box. Here’s a couple of pictures you’ probably appreciate of my inverted oil tank so after some training one of my desires is to get into aerobatic competition

 

[ronschreck]

Ron I enjoyed our visits when you came to the competitions held in Farmville, I wish they were still having them. Here’s a picture for you and Steve. Steve will be interested in the relationship between the inner and forward cowlings, but Ron take a look at the outta date calendar over the tool box. Here’s a couple of pictures you’ probably appreciate of my inverted oil tank so after some training one of my desires is to get into aerobatic competition

I forgot about that calendar shot. That is one awesome oil tank! Your craftmanship is second to none. Keep us posted on your progress. This is going to be an awesome RV.

 

[DanH]

Some interesting stuff there Morgan.

Load transfer from those new gear weldments isn't great, but that's a matter of design detail. The concept of an additional weldment fore and aft has merit. I think it would be better if they were tied to the F-844 to feed shear into the skin, but you're not going to change them now. Just keep an eye out for cracking and skin wrinkling where noted in the picture.

I'm a bit surprised to see a cover plate across the bottom, enclosing the one piece gear. Most of us have assumed the section under the center of the fuselage would bow downward when the axles ends are pushed up. Robbie said no?
.

 

[VA Maule]

weldments and let flex

One of the very specific conversations Robby and I had was regarding the flexing of the center span of the gear and I inquired about installing the WD-813 and associated hardware along with match drilling the holes to accept the AN-7 inner gear tension bolt his response was absolutely do NOT!!drill the gear ANYWHERE he was very adamant about that. He went on to explain very little movement would be through the center and that the Flexing would occur through the uniform taper of the length of the gear legs. To quote him but not necessarily verbatim “ It will act like a recurve bow of a bow and arrow the flexing will be noticed proportionately greater further out towards the ends where the string (wheels) would be attached and progressively less as in stiffer as approaching the mount and I doubt that it will move a 1/4”or less @ center span and if you’re gonna land it that hard you’re going to have a lot bigger problems than the flexing of the gear “

The forward and aft added stiffening braces at best are a compromise. Unquestionably a modified version of the WD-822 would have been better and hindsight always being 20/20 or better , I probably should have fabricated a custom WD-822 with the bottom strap extended beyond the forward and aft bulkheads of the gear towers to equal the length of the the modified U-803 clamp brackets with the side panel of the WD-822 also extended equally . However that thought was not considered at the time (that hindsight 20/20 thingy). But one indisputable benefit that I have obtained is I have great accessibility to check the torque on my gear bolts.
The overall strength of the F-844 mid forward shoteron (my name for it) is compromised by the fact it’s been milled out thinner to accommodate the F802-D and the point of that thin spot fore and aft is the wrinkle points incidentally that same point is the also the termination point of the gear tower and the classic ground loop bend the airplane point and once again this hindsight thingy comes into play. If I had thought earlier for a ground up modification to the extension of the side plate of the WD-822 perhaps this potential failure model could be eradicated but fixing all potentials is a never ending chase.

Dan, as usual you’re insightful comments are spot on and only work to improve our experience with our hobby. Hopefully the modifications I’ve made will perform adequately, time and progressive testing will tell.

Y’all stay tuned same RV channel , RV time to be announced due to other network programming.

 

[Snowflake]

Looking at this picture:
https://vansairforce.net/community/attachment.php?attachmentid=36793&d=1673658304

I'm wondering if the thrust line of the engine relative to the airframe is lower than where it would be with a Lycoming? The axis of the prop seems low to me, or is it just the angle of the photograph?

 

[VA Maule]

Thrust line

Good eye there Snowflake. I touched on this in post #50 when I commented that I didn’t want to alter Vans stock forward top skin , windshield , or baggage door so in order maintain the standard configuration of these the thrust line center was lowered approximately 4”.
If you look closely at the picture you referred to can see the wooden straight edge that was attached to a temporary bracket to hold it on center line and clecoed to the baggage hinge location. The straight edge was for setting hight and extension of the NACA cowling

Here’s a couple of glamour shots that sorta show the relationship

 

[D Weisgerber]

Do you have 2 Red Cube fuel transducers? The more I look at this the more I'm impressed.

 

[Northernliving]

Morgan, could you run through the modifications to accommodate the one-piece, lengthened gear? Although the radial catches the eye, the gear is the interesting structural change.

There are a number of people who have done the Grove one piece gear (conventional height) modification. If you are interested, I may be able to dig up a name or two.

 

[VA Maule]

Red cubes

There are 2. One counting incoming fuel through the 3/8” supply line and another counting the fuel returning via a 1/16” restricted fitting at the optional TBI exit port thence a 1/4” line back to the Andair duplex fuel valve and the tank it was drawn from. All of the counting done by the pair of cubs is interpreted by a pair of Electronics International CGR-30’ P & C. In the lower right portion of the panel.

 

[Harvey]

Rotec

Hi, Congratulations on your RV8R build to date. I have a fair bit of time behind the Rotec R3600 in my Spacewalker, and have had a number of discussions with Brian during and after his fitting the Rotec to his RV8.
There are a number of little differences between the Lycoming and the Rotec, particularly the oiling system, and replacing the 3/8" feed and scavenge lines with larger 1/2" ( -8) and replacing the banjo fittings on the pumps with high flow 90 degree items will drastically improve oil pressure throughout the operating range. I thoroughly recommend these mods.
I see you have gone with longer gear legs, as I did on the Spacewalker ( 9.5" longer) and still had to use a max of 78" diameter prop. I love the look of the longer legs and the more aggressive stance, and you may do too. It will be interesting to how the 8 performs with the large diameter prop.
I see that Brian has changed over to a Verner 9 cylinder radial, but haven't heard anything on how it performs since the initial video was posted.
If you have any queries, I am happy to help in any way.

 

[VA Maule]

Thanks for the insight on potential oil line improvements, I’ll keep this in mind should oil pressure issues present themselves. Glad to hear that your R-3600 is working well. If I may ask how many hours do you have on your engine?

 

[VA Maule]

Into the blue

Big BIG news today!!!
First flight was accomplished today. I’m pleased and exhilarated to report that she tracked straight down the runway for takeoff with just a little right rudder, climbed out straight and true, flew around the patch for a little while just as steady as a rock with the ball centered hands free no heavy wing issue ( really relieved about this considering the troubles others have reported) . Did some slow flight and then couple of non-event stalls , breaks were preceded by a slight but quite attention getting buffet and a straight forward nose drop without any wing dropping , lightly relaxing the back pressure and she was right back to flying, adding little bit of power right back to straight and level . Coming in to land pulled power little too much and that big 84” prop was like a “drag chute” putting the breaks on had to put a good bit of the power back in to arrest the surprising distant rate after this dose of self inflicted excessive excitement, she rolled right on the grass with just a little bounce and only one, rolled out nice and straight to a no breaks needed stop in about 450-500’

Very happy guy here!!

 

[Jetmart]

Congrats! Looking forward to see and hear more.

 

[rv6n6r]

Pictures! I want to see this thing all cowled up and flying.

 

[jhrubos]

congrats

congrats on flying your Van's aeroplane. is it time to change your handle?

 

[goatflieg]

I am also looking forward to more photos and hopefully some video too.

 

[plehrke]

Congratulations

Big BIG news today!!!
.
.
.
Very happy guy here!!

I (and many others on this forum) Will be interested in any data you post on flying quality and performance numbers.
Good luck on your transition from experimenter/builder to test pilot.

 

[Dan 57]

I am also looking forward to more photos and hopefully some video too.

Same here, with a good sound pick-up pleeease

PS
Pity (gotta admit not putting my face in the book ) we don't hear/read anymore about the other radial, Verner re-engined -8...
An -8 is as boring as any other RV, but a radial -8, love it

 

[goatflieg]

An -8 is as boring as any other RV, but...

... slowly we turned... step by step... inch by inch...

 

[Mikeyb]

A regular -8 may be boring but a radial -8 is kind of sad.

 

[Freemasm]

Interesting

Our friend in the CH's mastery of English appears far better than the vast majority of VAFer's skills the multitude of Swiss languages. I read his comment as a reference to originality; so, disagree if you want but I'm with him.

Building a well designed kit takes skills. Having the advanced skills and ambition to take on the subject aircraft should be a point of pride, not ridicule. Got to see Flyboykelly's Radial 8 in person. There's a reason it has been featured on Magazine covers and subject of EAA articles. He closed his round engine thread because of similar "stuff".

Throw more stones. No one will judge you.