Weight & Balance with Catto Prop

I finally (I think) finalized my engine/prop combo. IO-360 from AeroSport and a 3-blade Catto. Unfortunately, my previous decision was for a C/S prop, so my battery tray is in the back.
Will I have to move the battery to the firewall for a Catto?
I envision most of my flights being solo, with mild acro. if that helps?
PIC = 200#

Thanks for the PIREPS...

When you say IO-360, is that the Angle or Parallel?

My 0-360 with Catto Came out nicely balanced at a CG of 80 for solo full fuel.

If you use an PC-680 or even a lithium battery I would just leave it in the back and you should be fine. I can email you my w&b spreadsheet to play with if you like.

Andy,
Funny, I was just purusing the "Show us your Panel" forum and was struck by how similar your panel will be to mine; mostly empty, except for the SkyView.

Yes, I'd like to play with your W&B software?Thanks.
I'll be staying away from lithium for a while?for the same reason I won't be flying my company's new 787 for a while.

As far as the valves?I'm unsure. It'll be 180 hp, though.

Thanks for your help.

Catto

If you are going fixed pitch and you are in the middle of your build, I would put the battery in front. Vans designed it that way. Better W&B but more of a reason is simplicity in wiring, ease of access to the battery and you avoid the cost of running large heavy expensive battery cables to the back of the plane. The KISS theory at work.

+1 on battery in the front, if you can. I have over 2 pounds of battery cable due to the battery in the back.
Plus, LiFePo4 batteries should perhaps be outside of the passenger envelope.
Forward of the firewall offers some venting.

I had a Three blade CAtto prop on my 8 with the Oddsey battery on the firewall , my max GIB was around 200 lbs. and no additional bags . The I added an 11 lb. weight ring on the starter ring gear / flywheel , and now the GIB went up to 218 lbs. no baggage . I now have a Hartzel BLended Airfoil prop and can take a GIB at 260 lbs ! But with Full Fuel run out of gross weight . . The Catto was a little Faster @ 2850 RPM 210 Ias mph as I remember , But the Hartzel Oh " The Hartzel has it All on Take off ! Wow ! No contest their . BTW the Battery is still on the firewall . . I Love the Hartzel Prop !

HIIFLY said:

I had a Three blade CAtto prop on my 8 with the Oddsey battery on the firewall , my max GIB was around 200 lbs. and no additional bags . The I added an 11 lb. weight ring on the starter ring gear / flywheel , and now the GIB went up to 218 lbs. no baggage . I now have a Hartzel BLended Airfoil prop and can take a GIB at 260 lbs ! But with Full Fuel run out of gross weight . . The Catto was a little Faster @ 2850 RPM 210 Ias mph as I remember , But the Hartzel Oh " The Hartzel has it All on Take off ! Wow ! No contest their . BTW the Battery is still on the firewall . . I Love the Hartzel Prop !

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Joe,

Thanks for that perspective. I know what you say is true, I had an MT electric CS with the Subby H6 and its take off performance was impressive, about the only thing impressive with that engine in final analysis. I also know take off performance is more impressive yet with your set up.

The Catto is a wonderful compromise between cost, weight and performance. That's why I am with it. But if ever I win the lottery or some other unexpected source of green stuff, I will consider a CS prop. I'd probably go with the MT electric again, I know it well.

FWIT worth, my empty CG is 78.54 with the PC 680 on the firewall. Empty weight is 1029.

I love to fly the 8, makes one feel younger than he really is.

Yeah, this is somewhat disappointing, as I pictured myself beyond "the middle" of my build, as I'm deep into wiring….having already laid the monster cable to the back. Looks like the right thing to do is pull it, and the tray out and re-wire for a firewall battery tray.

David-aviator said:

FWIT worth, my empty CG is 78.54 with the PC 680 on the firewall. Empty weight is 1029.

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Nice, we are very close. I'm eagerly reading every post you have David about the flying!

Mine is 78.17 and 1035 empty.