Weight and balance numbers

[AltonD]

Originally Posted by LarryT

...and light prop will move the CG forward. ....

LarryT

Doesn't a light prop move the CG towards the rear?

[David-aviator]

Originally Posted by Jamie Aust

port = 419 lbs
stbd = 416 lbs
nose = 240 lbs

The problem I have is this. 1 x (about 250 lbs) co-pilot seated, 3/4 full fuel, slider canopy open, when the other pilot ( about 200 lbs ) got on the step and tried to get onto the wing, the tail hit the ground.

Note this was with the engine cowls top and bottom off, no wheel pants. Even when I did have them on, it still feels AFT CofG.

Jamie,

I just got off the phone with Sam at Saber intending to get some info on the device he has to help fix your situation and he asked if I was calling on behalf of Jamie in Australia and I said yes. You are one step ahead and have already contacted him.

That 14# crush plate would cure your problem. The only issue is how much it would cost to get it to you.

[N941WR]

Originally Posted by AltonD

Doesn't a light prop move the CG towards the rear?

You are correct, except his title states, "320 engine mount with 360...". Thus the longer engine mount and heavier engine with a light prop might just work out fine.

I'm not sure what the length difference between the 320 and 360 mounts are but I do know the mount I had with the 290 was 12" from the firewall. The mount I now have with the 360 is only 10" from the firewall.

Granted my -9 is different than the -7 but the O-360 and Catto prop with the 10" mount work out great!

[Spindrift]

Left 503
Right 499
TW 75
Total 1077 C.G. 81.78

ECI IO-360 180 hp with 3 blade Catto, simple panel, night vfr with MGL Enigma EFIS, no interior except cloth covered seats and some blue foam with carpet on the floor between the ribs.

However, this is after adding a 20lb Saber Mfg steel crush plate and longer bolts. With the 1 pound aluminum crush plate, I was at 1056lbs and 82.37 C.G., which only gave me 32lbs of baggage capacity. Adding 20lbs to the nose added 18lbs to the rear baggage capacity at landing weight with an hour of fuel reserves.

For Oshkosh, I strapped tools and tiedowns under my co-pilots legs, and velcro'd a plastic box in front of the fuel pump for spare oil and canopy cleaner, thus putting some of the cargo weight in front of CG.

[LarryT]

Originally Posted by AltonD

Doesn't a light prop move the CG towards the rear?

too late at night. A light prop absolutely moves CG aft. The 320 mount moves the engine,flywheel and prop forward, therefore moving the CG forward.

I hope I stated it correctly this time.

LarryT

[Jamie Aust]

Originally Posted by David-aviator

Jamie,

I just got off the phone with Sam at Saber intending to get some info on the device he has to help fix your situation and he asked if I was calling on behalf of Jamie in Australia and I said yes. You are one step ahead and have already contacted him.

That 14# crush plate would cure your problem. The only issue is how much it would cost to get it to you.

Thank you David, Im getting a shop here in Australia to CnC a 19 pound steel spacer for me. My spacer will have a recess in the middle so I will not need to get longer bolts ( $100 a set )
I hope this should help with my aft CofG. I hope to get it fitted in the next day or so, and will also be getting a prop balance done. I will post my findings then.

[schristo@mac.com]

finished without paint:
left 516
right 512
tail 62
empty 1090
CG 79.5

with paint...

[Remag]

RV-7 flying, painted outside, no primer inside, full Classic Aero leather interior, XP-360 with Sensi FP:-

Left main: 517
Right Main: 518
TW: 63

CofG: 79.58

[704CH]

Weight without paint:

Left 512
Right 508
Tail 66.5 (Rounded to 67)

Empty Weight: 1087

CG: 80.34

Details: http://www.704ch.com/2013/03/the-big-weigh-in.html

[hydroguy2]

Chad, what engine, prop,and anything else special equipped. This helps with others trying to figure out how there's may balance.