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RV-8 Angle Valve quesiton

flyinhood

Well Known Member
Hey everyone. I have a friend who is possibly looking at an 8 angle valve. He is around 250lbs. Does anyone have any knowledge about CG issues / envelope / ballast needs ect that could help out. He's not sure if he needs to stick to a parallel or not.

Thanks in advance!
 
Hey everyone. I have a friend who is possibly looking at an 8 angle valve. He is around 250lbs. Does anyone have any knowledge about CG issues / envelope / ballast needs ect that could help out. He's not sure if he needs to stick to a parallel or not.

Thanks in advance!

Mine is a 390 with a metal Hartzell, so it's as nose heavy as any. Put him in touch and I'll send a W&B Excel spreadsheet.

Short version; when solo, it will be at, or a little beyond the forward CG. Doesn't seem to hurt anything, although it will run out of trim at low speed, and the aft stick forces get high during acro.
 
Hey everyone. I have a friend who is possibly looking at an 8 angle valve. He is around 250lbs. Does anyone have any knowledge about CG issues / envelope / ballast needs ect that could help out. He's not sure if he needs to stick to a parallel or not.

Thanks in advance!

If he mounts the battery in the aft location he should be fine.

Carl
 
200AV with metal Hartzel BAF, rear battery. 1143 and 80.25 CG empty. Still has some room before it runs out of the fwd limit but flies just as Dan describes.
 
If you run the Hartzell composite blended airfoil prop it would probably be pretty close to a wash cg wise.
Hartzell composite is about 20 pounds lighter out on the nose vs the angle valve being about 35 heavier at engine location.
 
Hey everyone. I have a friend who is possibly looking at an 8 angle valve. He is around 250lbs. Does anyone have any knowledge about CG issues / envelope / ballast needs ect that could help out. He's not sure if he needs to stick to a parallel or not.

Thanks in advance!

It should be no problem. I?m about ~245 and fly an -8 with an angle valve and heavy Hartzell blended airfoil prop. Since the front seat of the -8 is behind the CG a heavy pilot helps offset a heavy engine/prop.

Skylor
 
Just one other note. I've owned two 8s. One was an 0-360 with a composite fixed pitch prop. In other words, it had an empty CG further aft than my current 8 which is an IO-360 angle valve with a Hartzell metal CS prop which has an empty CG right on the forward limit. I very much prefer the second airplane. Everything that goes into it ( nose baggage excepted) moves the CG aft so, as soon as I sit down in the cockpit, the CG is fine. Fuel does the same. Passengers and rear baggage even more. The big difference is that this airplane doesn't seem to suffer from that landing "twitchiness" that my first 8 did. Landing that aft cg airplane, with someone in the rear, took a whole different technique.
 
Angle Valve CG

Good answers, so I'll just add this. It is a MUST to put the battery in the rear location. I recommend using a standard 25 AH battery instead of a smaller and lighter battery. Don't even think about using an EarthX type LIFE battery. You need the ballast in the rear. If you're going to use lead back there for CG it might as well make lots of electricity for you!

The Doll has an I0360A1B6 with a Hartzell, and a Christen inverted oil system so she is probably as heavy firewall forward any other 8 out there. I use a standard aircraft battery. I mounted the battery and starter relays on the battery tray. Finally, I have a small tool kit mounted on the rear cargo compartment shelf above the battery. I biased the elevator trim to give more up trim. Still, flying solo at approach speed, I run out of up trim and must carry a little power to unload the stick. She flies normally with a GIB in the back seat.
 
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