retnavycdr

My Feedback: (190)

A good friend (rcpilet) and myself are both getting Great Planes Pitts Specials ready to fly, perhaps even in some sort of formation, and I am wondering what the LARGEST engine was that any of the RCU readers have used on this particular plane? He is putting a FOX 3.2 gasser on his and I was going to use a FPE 3.2 on mine, but now I am thinking about the Fuji BT-64 EIS. Last week another friend made a maiden with his GP Christien Eagle, using a Quadra-50 and it went down when turning into the wind (about 15-20 mph). This has me wondering if 50 cc is enough here in Colorado, at about 5,000 gfeet of altitude. My firewall is beefed up quite a bit and think it would supprt the 64 cc. Any opinions?

Tired Old Man

My Feedback: (1)

50cc is way more than enough, even at your elevation. One possible reason for the loss with the Quadra was the potential for an extremely high wing loading and accelerated stall during the turn due to an excessively heavy plane. The heavier it is, the faster it has to go, and the more it weighs in a tight bank due to "G" loading. You only have so much wing area to start with.Increased density altitude makes that situation even worse. Being nose heavy adds a few more nails to the eventual coffin. If either the Eagle or the Pitts is balanced to the book, you will be nose heavy.

My opinion is that if you want those planes to fly as good as they could, get them lighter with smaller engines not heavier with larger engines. The 3.2 in either version is already at the outside edge of the weight envelope.

rc bugman

My Feedback: (30)

Roger,

I tried several engines in my 1/3 pitts before I settled on the one that I fly in it. The plane like all biplanes is very draggy. A RCS-44 twin barely flew the plane. A 3W-48 twin which is rated with slight more power than the 3w-50 which has more power than the DA-50 flew the plane but the performance was not the "over the top" performance that I desired. I settled on a 3W-70 twin, an older model which is no longer made and weighs @5 lbs. This engine gives the plane outstanding performance with knife edges, unlimited vertical and hovering. All up plane wt is about 18.5 lbs. The plane has no particular bad habits and flies well. I don't believe wing loading is the issue stated by Silversurfer but then I fly heavily loaded RC research planes. I believe that you will be dissatified with a 50 cc engine in the pitts at your location. I am located at about 1000' ASL

Elson

Capt Jim

My Feedback: (168)

I saw one fly with a DA-50...and another with an OS160 two stroke. They both flew extremely well.
Good luck

Rcpilot

My Feedback: (78)

Roger:
Jim's Christian Eagle only had a Quadra 35cc in it.

That combined with pilot error--and it's all over but the cryin'

I was tempted to put a G-62 in mine early on. But I ran out of motors. All my G-62 engines are going into other planes. So, I was going to run a Stock G-45 untill I saw what happened to Jim with the Quadra 35. I don't know how much difference there is between a Quadra 35 and a Zenoah G-45, but I got scared and decided to put the Fox 3.2 on it. I had the Fox 3.2 earmarked for the Giant Stinger kit--but it'll be a long time before I jump into building that, so the Fox can get a workout on the Pitts in the meantime. It still has crosshatches on the cylinder, so it needs to be run anyway.

Tired Old Man

My Feedback: (1)

Just an FYI. My Pitts with a Brison 3.2 came in at 16.5 pounds. I normally fly at a field elevation of 1,400 feet msl, and the temps in the summer are above 100. There was NEVER a shortage of power at any temperature.

Antique

My Feedback: (4)

We race the GP Christen Eagles with GT 80s for power...
A GT80 is smoother than any single...The hinges were replaced and servo mounts strenghtened...One was recovered with MonoKote...This year they're getting new foam wings with a better airfoil for more speed....Should be around 130+ mph....
I would think an old 445 twin would be perfect for a sport plane....At ANY altitude..[8D]

RTK

My Feedback: (1)

Another option would be the BME 55x if you are all out of 62's. As mentioned before keep it light and it will fly right.

In fact I am e mailing Keith today and ordering a 55 for my Pitt's which has been completed less radio gear and engine.

Silversurfer did you hear that and I will prove one of these will 3D well. Let me rephrase, Maybe not great, but good enough to have fun with.

Rcpilot

My Feedback: (78)

The Christian Eagle that Roger mentioned was anemicly powered to start with.

Then the pilot made the decision to do the maiden flight in a 15 knot headwind.

Then he didn't gain any altitude. He was at best 75' above the ground.

He made a downwind turn at 75' above the ground.

He throttled back to 1/2 power.

At that point, the wind blowing at the tail was stronger than the forward thrust that he had available. The tail started to spin around as the plane was weather-vaining back into the wind.

Rather than throttle up and kick in the rudder to bring the nose back into the wind, the pilot faught the plane and ended up flying it sideways at low power settings. All the while, trying to straighten the plane out and continue on his downwind leg at 1/2 throttle.

The plane, flying sideways, stalled and corkscrewed in. He managed to get it straight and level before it hit--but it still went in hard, and folded the LG and cause some structural damage to the fuse. and wings.

100% pilot error.

Underpowered. Maiden flight in a 15 knot headwind. Poor throttle management. Dumb thumbs. Stalled. Corkscrewed. SPLAT!!

100% pilot error, but he won't admit it.[sm=lol.gif]

Volfy

My Feedback: (23)

I have seen these two GP 1/3scale Bipe cousins fly with anything from Quadra 40cc, Fuji 50cc, 64cc to Zenoah 62cc. All appear to be good sport flyers - and I hope nobody thinks these planes as anything but sport flyers. 3D monster these are definitely not. The GP ones are big enough to mimic the full scale flight & ground handling characteristics - good or bad. I doubt you can change that dramatically by engine choice alone.

I still have my Christen Eagle II in the same state for over 1yr - wings joined and tail feathers glued on. I doubt I'll ever get to finish it. If I ever do, I'll probably go with a 50cc with elec ign, mostly so it will be completely hidden in the cowl. Fly it like you should any big Pitts/Eagle and any 50-60cc would do just fine.

retnavycdr

My Feedback: (190)

RCIGN1, RCPILET, et.al., Thanks for the many informative responses. I guess I thought the White C. Eagle had a bigger engine than it really did. I thought with sufficient power and speed on the DOWNWIND leg he could have gained more altitude, and certainly more speed to avoid the crash. I am pretty well inclined to go with the First Place Engine 3.2 ci (52 cc) with a 20 x 10 or 22 x 10 Bolly. I know that Rcpilet is going to try to fly circles around me, but maybe I can stay enough in front of him to prevent his getting close enough to give me the raspberries!!! Thanks all. (I really ought to take the one suggestion for the big Zenoah Twin GT-80) ANyone got one for sale??

Rcpilot

My Feedback: (78)

I don't know if mine will hover or not. I doubt it. With a Fox 3.2 and 4500' elevation--doubtful.

If it does, cool. If it don't, cool. It's not my idea of a 3D plane either. Just a nice, big, scale, aerobatic bipe. It doesn't have to hover or torque roll. As long as it'll do a knife edge and a nice aileron roll without wobbling around, I'll be happy.

I'd like to fly mine in IMAC this year. Probably get my butt spanked, but who cares. No one else will be flying a bipe in IMAC.

I do have a GT-80 sitting on the shelf though............................[sm=spinnyeyes.gif]

retnavycdr

My Feedback: (190)

OK, Rcpilet!!!! How much for the GT-80?

Rcpilot

My Feedback: (78)

Oh, thats not for sale. I was joking about putting it on my Pitts.

I got it NIB cheap, and have since added aluminum mufflers and C&H synchrospark ignition module to the engine. Never started it.

I'm actually saving that engine for my World Models 90" Extra 330L. It's that big blue one sitting downstairs in the shop. Stupid Power!!![sm=punching.gif]

retnavycdr

My Feedback: (190)

OK OK Just thought I would ask. So I guess it is settled then....3.2 cubic inches of gasoline power in BOTH planes?

AJF--2

My Feedback: (119)

First Pitts had a Taurus 3.2 with a PK Plus 22/8---SPECTACULAR PERFORMANCE! (battery stupidity)
Second Pitts has a FPE 3.2 with a NX 22/8--- just as good, but I am at sea level.

PS-- still have the Taurus if anybody is interested. Back from Bill O with a new muffler.

Rcpilot

My Feedback: (78)

Sorry, that GT-80 is going to turn my 90" WM Extra into a rip snortin'--fire breathin' 3D monster.

You've already seen my bipe. The Fox 3.2 is mounted and the bolts are loc tited in. She's not coming off now.

I need to get a gear set for that JR 911 servo and then build all the tail linkages for the elevators and the rudder. Mount that pilot and glue the canopy on. Then mount the RX and switches.

I'm torn on if I should use dual batteries on my RX or not. It's a big plane, and I'd normally run 2 batteries on something of this size, but I'm running out of ports in this 8ch RX, and I don't want to put Y-harness' on anything. 2 elevators. 2 rudders. JR Matchbox for the 4 aileron servos. 1 throttle. 1 choke. Thats 7 plugs and I only got 8 ports in the RX. That only leaves me 1 port for battery, unless I Y-harness the choke and 2nd battery together. Or, I can give up the choke servo and just run a manual linkage through the cowl.

I just hate using Y-harness' in planes this size. You know me--king of perfection.

I could go out and buy a $200 JR 10ch RX, but thats rediculous IMO. I'd rather run dual Hitec 5ch RXs than pay $200 for a RX. That would give me 10 ports, and I HAVE the RX's here in the shop. But, I'll be the only guy using dual RXs on a 1/3 Pitts. I'd rather do that than buy the $200 JR RX or use a Y-harness though. Am I crazy or what?

We need to get yours over here and go over the firewall. Give it a once-over and then slap that FPE 3.2 on it.

I am really looking forward to flying them together. Same power, same plane. Just have to keep from getting them mixed up so we don't crash.[X(]