how well would a fuji 86cc engine pull an 18-20 pound plane for 3D? i cant decide if i want to give up some power and use the fuji. or suck it up and go ahead and spend 1200 bux on a BME 105cc... what kind of performance would i get with the fuji 86?? [sm=spinnyeyes.gif]

Heck man, you can 3d an 18-20lb plane on a DA50. Generally, 100cc airframes are in the mid 20s to 30lb. I'd say if you can get it to balance with that engine, it'd be fine, assuming the Fuji is as powerful at the rest of the 75-80cc engines out there.

Use the Zenoah G62 on your plane. I have a TOC 30% Yak 54 and it weighs 19 pound and that engine will do anything you want that plane to do. A guy on ebay sells them at $264.94. Great deal.

Gibbs

Power-to weight-wise, the Fuji AND the G-62 are dogs. The Fuji weighs 5.7 pounds by itself and costs $779 and doesn't have electronic ignition and will not deliver near the power of a ZDZ or 3W 80. The Fuji has 7.5hp @8500RPM, while the 3W has 8.1hp and tons of torque, and only weighs 5.05 pounds (I believe that includes the weight of the ignition). It only costs $675.You can get the 3W at:
http://cactusaviation.com/Products/E...80/engine.html
The ZDZ Super80 weighs about as much as the 3w when you add the weight of the ignition, but is notorious for being an absolute powerhouse at 9.5hp! It costs $775 and you can get it at:
http://troybuiltmodels.com/EngZDZ.htm
If you are willing to spend that $1200, then don't waste it on a BME 105 (I don't even know if they still make it). Go for their new 115. It is the same price, but over a pound lighter than the 3W or ZDZ, and has WAY more power!
I don't know what plane you are talking about, but is that the claimed all-up weight by the manufacturer and is it designed around an 80cc class engine? A typical 80cc plane will have around 1650 square inches of wing area and would weigh around 15-17 pounds without the engine, muffler, ignition&battery, prop or spinner. Once you add all that stuff, you usually end up at around 21-24 pounds.
I have said it before and will say it again - power-to-weight is only one factor of a good-flying 3D plane! Equally important is the wingloading - on a typical 80cc class airframe, you should have no more than a 31 ounce wingloading for killer 3D, and anything higher than 32 on a plane in this class is just a glorified warbird, IMO!

Warbirds --always getting the rap for being lead sleds .
someday -I gotta put together a P51 or Spitfire - built in same manner as the aerobatic stuff I like to do-
No reason why I can't hit same weights/size as the aerobatic stuff
Either one is laid out to be a excellent aerobatic craft.
A super 80 full piped one at say 25 lbs &`1700sq- should be a hoot.

thanks guys, i should have said what plane it is. the plane is a modified GP extra 330L (wings lengthend 5 inches on both tips, so it brings the total wingspan to 110 inches. 18-20 pounds was the weight i was hoping for, the manufacturer claims an overall 18-25. the stock wing area is 1670 square inches. but with the added length its probably closer to 2000 square inches. (i don't know the math to figure that out [sm=bananahead.gif]). and also the stock wingloading is 26-30 ounces, that should be brought down with the increased wing area. i think im going to buy the ZDZ 80...9.5 horse power for that size of an engine is unbelievable.

thanks for the help guys,
James

That 330L is a nice-looking plane, but I think you will be hard pressed to get it below 22 pounds. Also, accoring to R/C Report, it only has 1607 sq.in of wing area. I figure your extra 10" of span only added about 120 sq.in, so lets be optimistic and call it 1750 sq.in. R/C Report also did their report with a G-62 which is slightly lighter than the 80's and theirs came in at 23.5 pounds. I'm guessing yours will be about 24 pounds, realistically. So you're looking at about a 31.6 ounce wingloading and a cubic loading of about 9. A "featherlight" aerobatic plane typically has about a cubic loading of 7.5-8.5 - a 9 is a good all-around aerobatic setup. If you can keep it around 24 you'll be golden!

last night i ordered the zdz 80. i asked for the free failsafe . then i found a six pound weight that the girlfriend had lying around and placed that inside the plane so i can get an estimate on the weight. and it came in at 22.6 pounds. im hoping i will be able to keep the weight of the engine below that to make this plane about 21 pounds. with the 55+ pounds of thrust that TBM claims this plane outta rocket out of hovers. ill let you guys know how she performs when i get the engine. thanks

Don't believe the inflated claims of 55 pounds of thrust. 35-38 is more realistic.

The true thrust can be wildly different

change prop/exhaust system AND position of cowl to prop ( extend the spinner out in front into cleaner air)
thrust will run from 35 - 45 easily and on right exhaust setup - much more I played a little loking at tihese measurements
My piped Super 80 turns a Mejzlic 27x10 at 6500 -on the ground- on an IN cowl muffler that rpm drops 500rpm +-
how much static thrust is that? I never measured it
switch to a good 26x10 and you may easily beat the 27x10 (on incowl muffler ).-- for static thrust
my 23 lb plane does rocket out of hovers and unloads (easy to hear it happen) as it accelerates vertically rolling.
at 22 lbs with the in cowl mufler - and ZM 26x10 it was still very good and ran 7000- 8000 static to level full speed rpm measurements
I personally don't pay much attention to the static listings -I go by best static AND in flight performance

I have that plane with ZDZ 80 RV. Its 24 lbs with canister and 4 aileron servos. 1 5955 rudder servo. CF gear, CF tube and heavy duty battery setup...

The RVJ is heavier than my RV and if you only added one rib at the end of the wings, you did not add that much wing area... Is the plane covered at the weight you listed. I estimate my plane has a full pound of monokote on it. 4 oz per wing panel so 1/2 lb for the wings and probably 1/2 lbs for the rest...

I can't see any way to get this plane down to less than 21 lbs with a 80 and have a flyable plane that is structurally strong. Unless it is not a Great Planes anymore...

My wing loading is more in the 32 oz area and the plane still flies great in 3D. I made larger tail surfaces and this thing has by far the strongest control authority I have ever seen. The plane is short so I think that the main reason of that, along with bigger surfaces.

I often get asked what the weight of the plane is and usually, people are surprised to see that its that heavy with such a small wing.

3D Joy, how did you enlarge your elevators? i enlarged them by moving the hingeline 3/4 inch forward, and extended the counterbalances up to the leading edge. im just wondering how you went about doing it. and i think it might be possible to lose almost a pound on this thing just by switching the heavy aluminum landing gear to carbon fiber and switching out the Nicad batteries with some Lipo's. plus there is the wing tubes , spinner and wheel pants that can be switched to carbon fiber. [sm=spinnyeyes.gif]

Elevators : moved the hinge line 3/4 inches and the trailing edge another 3/4-1 inch back. My elevators are HUGE in any standard. I left the counterbalances at stock location so they are right now quite non existent...

The landing gear and wing tube are CF on my plane and I saved almost 3/4 lbs (something like 11.something ounces). I use 1950 4/5FAUP 6V batteries. They are high discharge Nimh cells which are very powerful. They also are a bit heavy if compared with 3-times-more-expensive-LiPo-cells. My setup has more than twice the amp rating of LiPos, much cheaper, much simpler, much less capacity but can be fast charged at 2C or more so the argument of flight time is not applicable. Nimh are not what we got when the Hydrimax series came out...

My spinner is the Pete models 5 inch spinner. This is simply the lightest available. Very good quality and the shop is at 20 min drive from home. TBM sells his products and also have them in stock. This is great product.

Everything in CF is lighter except props. It looks strange to me but its a fact.