Ballast?
One thing I noticed running some scenarios from Dans W&B table is that you can end up with the CG aft of the aft limit if you have full baggage and full tanks when you start but only minimum fuel at the end of a flight.
If you look carefully
you will end up
way aft CG with a RV7(A) with full bags, if you have a light weight engine/prop. The most aft CG on Dan's W*B list is Cary Rhodes with an empty CG of 83.14" @ 1058 lbs. You'll noticed bags are limited to 60 lbs and there is no Acro limit. You can forget about the 84.5" Acro CG even solo, with fuel much less than full. Even limiting bags to 60 lb (vs std 100 lbs), you'll be aft the 86.82" CG limit w/ two 170 lb folks & full fuel by over 1/4". Yes, as you burn fuel, CG shifts further aft. With 14 gal you are 1" aft limit. This plane is begging for some ballast on the nose. (see below*)
Some workarounds when traveling, use soft bags on the floor (fwd of spar) with light stuff like clothes, secured so it does not interfere with the rudder.
>Use old fashion heavy starters and alternators.
>Fixed wood prop guys use the prop damper (about 20 lbs).
>Lead weight up from on the engine mount or on fwd engine area.
>Lead ballast could be remove ballast for local no baggage flights.
>If you don't want to do Acro or need to carry baggage, its not a problem.
>It would not take much weight in the starter/alternator area, like 20 lbs to move CG.*
Van made the RV7 for a 360/Hartzell. This is where the market was/is going. This combo on a RV4/6 is nose heavy, which was designed around the common combo back than, 320/wood prop.
Also priming and painting moves CG aft, since there is more surface aft of CG.
* Starting with 1058 lb / 83.14" CG,
20 lbs on the engine (big ol starter/alternator) moves wt/cg to 1078lbs/82.17", so 20 lbs moved CG almost 1" for this plane.. At least you could carry 40 lbs of bags with two people and 1 hr reserve fuel (10 gal). Forget dual Acro except with a 100 lb pass, 170 lb pilot, full fuel and no bags of course. Ballast can be good. 20 lbs of lead does not take much room.
PS - A 55 lb Hartzell BA prop would be the best solution. (I'm waiting for my commission check Mr. Hartzell.)