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Questions on RV-8 fastback slider

S

SteveS

I'm New Here
Hi everyone,

Sorry cor the long winded post but I just got back to building my RV8 and learned there is a fastback slider mod for the RV8.*

Back in 99 when I was deciding what to build, I took my wife with me to demo the Harmon Rocket and Van's RV8. I liked the look of the Rocket, but I also liked the sliding canopy function of the RV8. *My wife who is a photographer, liked the additional width in the back seat of the RV. So as the saying goes (happy wife, happy life). I'm building an RV8.

My questions are:
*
How do the dimensions of the rear pax compartment of a slider fastback RV8 compare to those of the standard RV8 at the canopy level (side buldge vs straight) and at the side skins?

Does anyone have an RV8 with a slider fastback canopy installed that I could come and take a look at?

Any feedback on the Tom Clark mod package would be greatly appreciated.*

Thanks,
 
Kent Paser wrote a book: Speed with Economy.
He built then raced and modified a Bushby Mustang II, eventually converting it to a fastback.
I suggest you beg borrow or buy his book if you want to see a successful fastback slider. He quite simply added it over the original tail cone, so I thought that was a bit heavy, but ...to each his own.
My point here is that he shows the step by step way that he used, and you can get some very good ideas to help you decide what you want and how to get there.
You can buy one of the successful kits for an RV-8 slider also...
I think they look cool too. I just chickened out and built to plans. Maybe later I'll modify to a fastback. My canopy skirt is so long that it is a hard interference to the vertical stab when I take it off. So maybe I'll 'someday' cut the tail off my canopy near the rear seat bulkhead and design an upper bulkhead that fits to the new canopy tail, then work the profile back from there...
Or decide that I like to keep flying and leave it alone.
 
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Out of curiosity I superimposed Van's normal RV-8 outline over a photo one of the fastback mods (Clark):



I like the the looks of this particular mod because it gives a nice smooth line from the canopy to the turtledeck. However, also looks like it cut down headroom slightly. I think the Showplanes mod is a bit taller?

I'm skeptical that there is any measurable difference in speed with a fastback. I did some tuft testing of of the aft canopy on my "standard" RV-8 and could not detect any areas of flow separation. Also the RV-8s that have entered the SARL races over the past 3 years have been considerably faster on average than similarly powered RV-6s and 7s (data compiled by Bob Axsom). The 6s and 7s are all "fastback".
 
Since that's my '8 FB in the photo, I can make a few comments. The mod is a Tom Clark design. The rear of the fuselage is unchanged below the longerons with this mod. So the rear seat room is identical to the standard '8. You do have to bend forward more as you set down in the seat to clear the canted canopy, but once seated no difference other than the pass cannot see the rudder.

Tom ships new top formers for the turtledeck and plans/pixs for the remaining changes. The front roll bar is cut and canted forward about 15 degrees and the canopy frame is either scratch build or a modified Van's frame. In either case, some welding is required. The canopy comes from Airplane Plastics in Ohio. I purposely set my canopy a little low for looks and contour. Tom is a great guy and willing to provide good phone support, at least did several years ago when I was building.

As far as speed gains, I haven't isolated the fastback contribution as I have several mods that affect speed. Like an earlier poster, I don't think there is any "significant" gain from the FB.

I see about 187+- kts at ~75% power at 6000 feet with the IO390 and Hartzell BA prop. I haven't gotten around to try to duplicate the equivalent power as a IO360 to compare with Van's numbers, although when running around with other local 8's I usually am running 2-3" less MP (mostly due to the 390 hp difference).

I live in the Austin, TX area and would be glad to show off my bird. It is based at Georgetown, KGTU.
 
Thanks Scott, Alan and Deene,

This was my first post and you guys and this forum are awesome. Questions answered and help offered.

Is this a great community or what!

Deene, I'll private message you (I think that?s the correct term) and set up a time that?s convenient for me to stop by.

Thanks Again,
 
deene said:
I see about 187+- kts at ~75% power at 6000 feet with the IO390 and Hartzell BA prop. I haven't gotten around to try to duplicate the equivalent power as a IO360 to compare with Van's numbers, although when running around with other local 8's I usually am running 2-3" less MP (mostly due to the 390 hp difference).
Click to expand...

Deene - nice looking airplane!
 
I purposely set my canopy a little low for looks and contour. Tom is a great guy and willing to provide good phone support, at least did several years ago when I was building.

Deene,

I assume you set your canopy low to get rid of the "lip/bubble" seen on some of the FB mods who have simply cut off the aft end of the Van's stock canopy? Can you give details as to how much etc. How about your canopy frame, how much rework did that involve.

For what its worth -- I have not been able to reach Tom Clark. He does not respond to VAF post, private message nor email. I have also left voice mail with no reply. I suspect he no longer makes his FB kit...

Jeff
 
Rv8-fastback slider

I started the slow build fuse in july, I was able to reach Tom Clark by phone from one of his earlier postings on vansairforce.He seemed rather busy and did not have any bulkhead kits available.He did send me full scale bulkhead drawings, a material list and a cd of pictures and instructions. at this time I have the fastback dimpled and clecoed in place. Doug
SteveS said:
Hi everyone,

Sorry cor the long winded post but I just got back to building my RV8 and learned there is a fastback slider mod for the RV8.*

Back in 99 when I was deciding what to build, I took my wife with me to demo the Harmon Rocket and Van's RV8. I liked the look of the Rocket, but I also liked the sliding canopy function of the RV8. *My wife who is a photographer, liked the additional width in the back seat of the RV. So as the saying goes (happy wife, happy life). I'm building an RV8.

My questions are:
*
How do the dimensions of the rear pax compartment of a slider fastback RV8 compare to those of the standard RV8 at the canopy level (side buldge vs straight) and at the side skins?

Does anyone have an RV8 with a slider fastback canopy installed that I could come and take a look at?

Any feedback on the Tom Clark mod package would be greatly appreciated.*

Thanks,
Click to expand...
 
RV-8 Fastback

Does anyone have contact info for Tom Clark?

I'm getting the itch to do this thing again...

Nick "Hairball" Knobil
RV-8 N80549 (1st Flight - Jan 2003)
Aerosport O-360A1A, Dual LS CDIs, Ellison TBI, Whirlwind 200C
 
RV-8 Fastback

Thanks Mike,

I like the fastback...and I like the slider. Who says I can't have my cake and eat it too?

PS - I've been lurking around for years, and I bet you've welcomed more guys to this site than anybody!
 
YES!!!

Is the turtledeck a rig-up of your own design?

I haven't put a pencil to paper, but I would think there would be some issues with the way the canopy tracks back as you open it.

I've also been toying with the idea of lowering the overall height of the canopy and windscreen bow to achieve a chopped <?> look...

That PROJECT of yours is awesome, keep up the great work!
 
Anybody Know?

Hey guys! Reviving an old thread here... Does anybody know how to get in touch with Mr. Tom Clark? Reading through old posts here and on other threads, I've gathered that he hasn't offered the fastback kit for sometime now. Id love to get in touch with him and discuss his design. Any leads would be appreciated.
 
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