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Sport CARF Pitts - Engine Upgrade

reyn3545

100cc
OK... got the motor installed last night, and got it started up today. Just a little bit of tuning on carb to better suit the temp change from Florida, and it's running very smooth, on all 4 cylinders! Judging from how easy the motor started and ran, I think I may have inherited a twisted crankshaft, but those are the chances you take when you buy used. It was running, and most of the time on 4 cylinders, but it had an intermittent problem where the back cylinders would stop firing. I guess the hall sensor for the front cylinders was set to still fire pretty consistently, but the back pickup must have been retarded just a hair, and when you combined that with a twisted crank, it only fired about 80% of the time.

Anyway, that's behind us now. I wish it were just a little warmer outside... I don't want to sit there on the cold ground for half an hour putting this thing together at the field.
 

reyn3545

100cc
Is that a bad-ass looking red head or what?

I finished up the baffling inside the cowl (finally), and when I put the cowl back on, I forgot to install the aluminum louvers first (had to take them off to access the ignition modules)... so, one more time with the cowl off, but that should be about all the work I can do on this thing until I get it to the field

 

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reyn3545

100cc
I cut some vent holes in the bottom of the fuse yesterday,

Plane Stand 3.jpg


So the only thing left to do is CG the plane and wait for some good weather. Today's weather looks great for February, but we have some Boy Scout things to do with my son this afternoon.

Anyway, I put the plane together in the basement, leveled it, put the scales under each wheel, recorded the measurements, then put the numbers into my spreadsheet. Two very positive observations:

1. The plane weighs 54.25 pounds dry. I'm not going to argue wet vs dry weight, I'm just going to say it's legitimately under 55 pounds, so no "N" number required!

2. It balances out at 2.59 inches behind the leading edge, against a goal of 2.7 inches... 1/10 of an inch is close enough for me on a plane this size, so NO additional weights will be required!

The batteries are sitting way back, just forward of the stabs on a fuselage brace. I charge them through charge ports on the switches, and they are A123 cells, so no need to get to them that often.

I think I've ran out of things to do other than flying....

Final CG.jpg
 

reyn3545

100cc
I started the original build thread for this plane on 12/17/13... over 2 years ago. It's on it's 3rd motor. First motor never made it off the ground before I sold it. Second motor flew about 6 flights, but was incredibly boring to fly. I don't expect this motor to be "ballistic", but it should be much more fun to fly. I can't wait, it's been a long build!
 

dhal22

GSN Sponsor Tier 1
I started the original build thread for this plane on 12/17/13... over 2 years ago. It's on it's 3rd motor. First motor never made it off the ground before I sold it. Second motor flew about 6 flights, but was incredibly boring to fly. I don't expect this motor to be "ballistic", but it should be much more fun to fly. I can't wait, it's been a long build!

I'll pull in to GMA someday, there will be a big Pitts tearing up the sky and I'll know who's it is. :woohoo!:
 
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