At what point do I HAVE to make decisions?

I'm in the middle of a standard-build RV-7. My fuselage kit is due to arrive this week. I've started thinking about my choices for engine, prop, fuel system, panel and all the other wonderfully expensive stuff I'm going to have to hang on this beastie before it's done.

At what point do I have to start committing to specific engine/prop or other choices? I would like to know ahead of time what I'm going to run into during the fuse build that will require that I make a decision that I may have planned to put off until ordering the finish kit.

I think you should at least decide on whether you're going with carb or F.I. It's a fuel line plumbing issue. Then there's the firewall recess.
The engine mount ships with the finish kit.

Looks like you have already decided on a slider which comes into play when you work on the cabin structure of the fuselage kit. If memory serves, the engine/prop decision easily waits until the day you order the finish kit.

Like Lorne said, there are early fuel line decisions (at tank construction, for instance) if you decide on FI with a return line.

Other decisions can be made and acted on earlier than finish kit but do not have to be made prior to the finish kit purchase.

As has been said here many times, delay installation of the firewall recess until the last possible minute. The hole is a real help while doing firewall penetrations.

Question

Does one have to decide on carb or FI engine before ordering quick build wings (that come with fuel tanks completed and pressure tested)? Or, can a fuel return port into the tanks. Be added easily later?

Wings don't really come into play.

If your FI (i.e. AFP) has a purge return line, that can be tee'd into the fuel line in the plans. You can run it all the way back to the tank, but most don't.

What I would recommend is starting to touch base with some of the vendors to understand their lead time. You don't want to wait until a month before you need something, then find out the vendor has a six month lead time on delivery.

For example, it took almost four months to get my engine. It was dropped ship from Lycoming, which saved time having to be sent to Van's.

I would also spend a significant amount of time reading other builder's logs. See what worked for them, then draw your own conclusions what will work will for you. There are many deviations once you start the FWF and avionics portions of your build. Only you can determine which one is best for you.

So far I've committed to a slider canopy and a tailwheel.

I'm sure I will be going with FI, but less sure whose -- EFII, AFP or the old Bendix system. A lot depends on where I find the engine and whether it was originally a FI engine, or if I convert a carbed engine. I very seriously doubt the engine will be new.

I'm less sure about the prop. I'm leaning toward CS, partly because I keep hearing about CG issues without it. Since it seems I'll never be able to fly IFR, that simplifies the panel decisions somewhat but I will put that off until the last possible moment for obvious reasons.

I'm hoping some things will be a little clearer after seeing more RVs and talking to more owners & builders at Oshkosh.

rleffler said:

For example, it took almost four months to get my engine. It was dropped ship from Lycoming, which saved time having to be sent to Van's.

Click to expand...

Bob, that makes me laugh at a memory. I ordered my Lyc at SnF to get the show discount. It shipped so fast that I commonly make the exaggeration that it beat me home from SnF. Seriously, it was only a couple of weeks. It pinched the bank account a little earlier than planned so the early shipment stung a bit.

panel/avionics

while you don't have to commit to a particular brand or layout, knowing if you're going to need to mount AHARS/Magnetometer/AP Servo different battery ahead of time makes it easier to install the infrastructure before all the skins are on. Likewise wire run location, conduit if necessary and antenna location/doublers might be easier during fuse construction rather than later. If you're doing a ground power jack I would plan it now. Almost anything not in the plans is going to take some extra time, planning and may have consequences. I agree with Bob on lead times, as I've had to wait for a few things but fortunately (?) the building gets behind the planning and it hasn't been a problem.

==dave==

Gotcha. I am pretty sure I'll be installing someone's autopilot servos, ADAHRS and magnetometer. Most likely Garmin or Dynon, but whose? If you can predict the future, you're better off than I am. I'm not planning on ground power, but will probably go with a LiFePO4 battery. I have a couple of minor modifications planned for the fuse, nothing crazy.

I'm really looking forward to doing a lot of in-person Oshkosh research so I can get a good idea of where and how I want to mount antennas, as well as any other little tidbits I can pick up there. So far I've seen two RVs and a Rocket up close... not a great sample size.

I would recommend installing an additional port in your fuel tanks while building them, just for the "in-case" need of a fuel return line later on. You can run the plumbing in a finished airplane a lot easier than you can pull the tanks and install another port.