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RV-7a Questions

AKHM462

I'm New Here
Hello everyone,

I am very close to ordering a Vans RV-7a QB kit, and have some questions regarding the empty weight number presented in the data sheet on the Van's website.

1. The empty weight is ranged between 1,077 - 1,130 lbs. What engine is used to factor in measuring the 1,130 lbs empty weight?

2. What else is used to make up the other empty weight values besides the basic airframe i.e. paint/no paint, interior (leather or cloth), avionics (basic vs full glass), propeller, etc.

3. I will be using the UL Power 520iS Turbo engine and am curious to know if there are any advantages to the new nose gear option other than accommodating engine configuration?

I all of you for your time and consideration, and look forward to starting work on my Van's this summer!

Joe
 
RV7

I have seen so many accidents with "Other than Lycoming" engines. Do yourself a favor, don't overthink the build. Put a Lycoming Engine under the cowl. Its tried and true. My suggestion is put an Angle Valve engine in it - you won't regret having that extra power.
 
Last edited by a moderator:
There's a reason Lycoming (for one) has been powering airplanes for ????years.......it's called RELIABILITY.:)
 
If you propose to use an engine other than Lycoming, you will likely need to make your own engine mount, and your own nose gear, as it is integral in the "A" model.
 
I cannot speak to the motor mount issues you might have fitting the ul engine. That said they appear to be a well engineered aircraft engine. The design is not radical at all, but a newer fresher look at engines long overdue in my view. There are a number of aircraft at our airport running these engines and the seem to work well. It’s not like an eggenfeller or something like that. I fly behind a lycoming due to ease of install, no particular love of a technology half a century old. Good luck with the build, I may fly up to see the install myself if possible.
 
My 7A is just under 1100 lbs but not yet painted or IFR equipped. I imagine range of empty weight is also related to equipage.

The new nose gear is far more robust but also requires the Lycoming engine mount unless you plan to build your own and retrofit it. Of course, the older nose gear is also built into the engine mount but is far simpler to incorporate into a home grown mount. If the UL folks are providing a FWF kit, it would be a great alternative, IMO.
 
For questions about Vans specs, your best bet is to contact Vans support. They can give you the authoritative answers. The rest of us are speculating.

Overall, although I’m an engineer, I found it impractical to guess weight or CG before finishing the airplane and it changed again after painting. If you add a nice interior or 200 Hp engine or lots of mods you will be on the heavier side.

The 7a CG was designed consistent with a heavy constant speed prop. If you try to save weight there, your CG will move aft. I have a beautiful light Catto prop and was pained to have to add a 20 pound crush plate on the prop to improve my usable load in the baggage compartment.

If I were to build again, I’d go with constant speed prop and io360. I like my Classic Aero interior and would do it again despite being heavier than an unfinished interior. I’m undecided on whether I’d do an earthx battery again or stick with the heavy battery. I like my AntiSplat and extended slider mods and would do those for safety and convenience despite the small amount of weight.

All of the mods cost more in build time than I would have expected. I did a superior engine that was supposed to be drop in but spent more than 100 hours messing with cowl mods and fuel line routing and firewall penetrations. If I were more experienced, perhaps I could have anticipated them all, but I had to learn on the build. If you do a nonstandard engine, expect a ton of time sorting it out unless you are an engine expert.

David
 
Thank-you to everyone

Thank-you to everyone who participated in this discussion. I really appreciate everyone's time, and it has given me much to consider.

Joe
 
Done deal

Joe, Ray Lawrence in Sandersville, Ga already has the cowls and motor mounts for the RV-6,7,8,9, and -12 that I’m building....I was there two days ago (he’s 25 miles from me)...plus he’s testing the 220 HP turbo engine as we speak, in his RV-4.....so far, very happy.

Regards,
 
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