Bipe recommendation for a Ryobi 31cc
 

Hi,

I was wondering what bipes you guys are flying with Ryobi 31cc's, or similair gas engine, up front? I'm looking for something mildly aerobatic - loops and rolls sorta thing. It has to be under about 10lbs in weight without the motor tho' as we have a 7kg (15lb 6oz) limit here in England.

And/or can anyone recommend what sort of wing area would suit the 4lb Ryobi - is it still about 1200 sq. in. split between the wings? Or should it be more like 1500 sq. in. due to a bipes inherent inefficiency compared to a monoplane?

As always, many thanks for your advice! [sm=thumbup.gif]

Steve

RE: Bipe recommendation for a Ryobi 31cc
 

I just got my Ryobi.
I"m thinking of getting the Lanier Ultimatte Pitts
http://www2.towerhobbies.com/cgi-bin...?&I=LXX412&P=7

They clain 1112sq inches and 10-14lbs.

RE: Bipe recommendation for a Ryobi 31cc
 

Hi,
Get a Balas USA Phaeton 90 bipe. 70" span and should be just right. http://www.balsausa.com/kits/kit.htp?id=34&shopperid

Dave

RE: Bipe recommendation for a Ryobi 31cc
 

Purple Pilot,
I would think a bipe with a 70" WS would fly great with that engine. I have two Ryobi 31CC's on my 101" Ziroli B-25J Mitchell. Good luck.

"Keep 'Em Flying!"
Flak

RE: Bipe recommendation for a Ryobi 31cc
 

I don't want to rain on anybodies parade but know what you're getting into. I ran a Ryobi 31 conversion for a while. The power to weight ratio is very poor. Because of this, whatever airframe you hang this engine in should be light and have generous wing area. I had mine in a Lanier Stinger 120. The lesson I learnt from this is to stick with bigger name brand gassers with better porting. A friend of mine buys up old chainsaws and the like. I've seen the differences in design and quality between various brands. In my opinion, you get what you pay for.

RE: Bipe recommendation for a Ryobi 31cc
 

daryl: you didnt really answer his question. he didnt ask if you thought it was a good idea to use a ryobi. yes the comercial engine are a bit more powerful and lighter i think that is well known. for me its not about the cost but the fun of taking an engine that someone gives me and using it for something they would have never thought of. and believe me i have alot of motors now because everyone wants to get rid of a 2 stroke gas weed trimmer they think of me and my hobby. maybe its not about going cheaper but just a bit of sick joy of trying to get a weedeater to fly. the comercial engines rob me of this joy its mount fuel and fly. kinda robs me of the joy of tinkering.

purple pilot: i have wanted to put a weed trimmer engine in a biplane for a while and i saw a homelite 25cc go in a goldberg ultimate but he had to do alot of lighting to the frame. biplanes are always too heavy however i think that balsa usa phaeton would be about the best choice and look for ways to lighten without sacrificing strength in the air frame. make sure to place the fuel tank over the cg and leave soem room to help balance the plane with maybe putting servos in the tail. good luck and post what you can get done in the engine conversion section. might post questions there incase you have any there are alot of guys that have experience with that engine. i am by no means an expert but like i said earlier i like to tinker.

RE: Bipe recommendation for a Ryobi 31cc
 

Hi Daryl,
For best results with your Ryobi, Use a 10 or 11mm carb. You don't want to use one of the cylinders that have compression dumping slots above the transfer ports. These exchange power for easier starting. Also the two ring pistons are a little better. Use a free flowing exhust with low restriction. All Ryobi's weight about four pounds, but they don't all produce the same power. For good performance you should get into the 7 thousand rpm range.

Dave

RE: Bipe recommendation for a Ryobi 31cc
 

Carlos - I think I answered the question. I'm saying consider how much weight you can afford to carry and the power you need for your style of flying. For me personally, the smaller gas engines don't cut it. Your results may vary. My feeling is that you have to get into bigger engines before the cost/benefit and power to weight ratios get better. The tinkering thing - I fully agree. It is very satisfying to convert something to RC use. I happen to have a pair of Kioritz (Echo) 61cc twins sitting here in the basement with me. I've got a Zenoah G-62 as well. I think you get what you pay for. A Ryobi is fairly gutless compared to some other (albeit much more expensive) choices out there. Dave - I'm done with the Ryobi. I gave it to my brother. I wouldn't even consider running one now. I'd rather go with a Zenoah G-38 or 45.

RE: Bipe recommendation for a Ryobi 31cc
 

Biplanes and ryobi is a touch match. Flybaby's, PT-19 and Cubs do better. If its gotta have two wings look at the Lazy Ace series of plans.
Good luck

RE: Bipe recommendation for a Ryobi 31cc
 

This model was going to be my suggestion.

This model has lots of wing area to carry the weight. The Ryobi is not a power making demon, so
the model will have to fly "on the wing" instead of "on the prop". This would make a nice combo.

Ed Cregger

RE: Bipe recommendation for a Ryobi 31cc
 

I have been flying a Balsa USA Phaeton 90 with a 25cc Homelite for over 6years. It is a very satisfying basic biplane that flies the basic manuevers. I moved the firewall back 1 1/2 inches for balance purposes, and I would guess the Ryobi would require another couple of inces back, due to its layout.

RE: Bipe recommendation for a Ryobi 31cc
 

i get all my engines for free. after telling them what i do with them people give them to me. i have now three homelite 25cc weedwackers, one homelite 26cc chainsaw, craftsman 32cc the ryobi and a 21cc featherlite.

i have a ryobi that i think is unusable after i got it apart.the ryobi i found has a wallowed out muffler bolt holes. it ran just fine but there is no way to mount a muffler.

the engine i look forward to working the conversion after i get freed form a plane i am building for someone is that homelite chainsaw. i plan on if i can putting it on my hanger 9 cap 232 1.20. i will put all the servos in the tail and the fuel tank over the CG and i think i should get it balanced. though the chainsaw is probably going to come in around a g26's weight.

RE: Bipe recommendation for a Ryobi 31cc
 

Hi Daryl,
The Zenoah 38 and 45 are as close to a converted chain as you can get. They both are magnito engines and heavy. The Ryobi can be made to produce good power, it just takes more care in setting the engine,airframe and prop selection. I like the idea of setting up the plane so that it will take different engines. This allows me to experiment.

Dave

RE: Bipe recommendation for a Ryobi 31cc
 

Would the Balsa USA Phaeton 90 be a better match for a Ryobi 31 than a Lanier Ultimate Pitts?

The Pitts is 10-14lbs with a 60" wing and the Phaeton is 10-12 with a 70" wing..

Wing loading based on a 12lb plane would be 24oz/sqft for the pitts and 179 for the Phaeton.

Hmm I guess I answered my own question.. I guess the Phaeton would be a little more lively but would the Pitts still fly ok?

RE: Bipe recommendation for a Ryobi 31cc
 

The Pitts is a "muscle Plane", the Phaeton 90 is not. You would want more power in the Pitts, despite it being smaller, to fly the Pitts to it's design style. The Phaeton is more like a version of some golden age bipe. I recommend it.

RE: Bipe recommendation for a Ryobi 31cc
 

A friend of mine flew a Jerry's Big Boy (Morrise Hobbies) with a modified Ryobi engine. Mods - C&H ignition custom muffler larger carb, and sanded some off of the cylinder base, to increase compression. the set up weighed 12# and had enough power to climb out of a torque roll.

RE: Bipe recommendation for a Ryobi 31cc
 

Hi guys,
Many thanks for all your suggestions! I really thought that this thread had been forgotten about seeing as I posted the original question nearly 1&1/2 years ago! My, how time flies [X(]

I did eventually get the Lazy Ace (76" ) plans from RCM but just haven't found time this year to do anything with them [:o]

So this winter I'm thinking about a kit to make things a little easier... how do you think a Ryobi 31 would fly one of the Balsa USA 1/4scale WW1 bipes? Am thinking of the Nieuport 17 and BUSA suggest the Zenoah G-23 (26).

Thanks again,
Steve

RE: Bipe recommendation for a Ryobi 31cc
 

Hi,

I can't report on results yet, but I'm planning to use a Ryobi in a Dymond Modelsports Tiger Moth with a 72" wing span. I read a Model Airplane News article where they tested this airplane with a Zenoah G-23. It flew great with that engine, and I think it will do fine on the Ryobi. I like the idea of the Ryobi in this airplane as it is narrow and I won't have to cut up that nice slim cowl.

I'm thinking it would work fine in the warbirds you mentioned as well. Many of the World War 1 warbirds need extra weight in the nose anyway. You might have to mount it so the the carb goes through the firewall as the engine is a little long sometimes in an airplane that was originally designed for a radial engine and a short cowl.

A lot of people are using this engine with good luck. It's not the most powerful out there, but it does ok. I think the ones that bad mouth it are looking for "3D" performance, and in that case they are probably right to want a lighter and more powerful engine. For me, the enjoyment of watching people's faces when I tell them the airplane has a Weedeater or chainsaw engine is priceless, and I don't fly "3D". (I do like vertical climb performance and aerobatics however, and I get plenty with my conversion engines!)

AV8TOR

RE: Bipe recommendation for a Ryobi 31cc
 

I had a Great Planes Tiger Moth 60 ARF with the ryobi and it flew great, sounded even better. AUW was about 12 lbs- not very aerobatic, but a fun relaxing flyer that looked great cruising around. Plenty of power- actually too much, flew around 1/2 to 3/4 throttle

RE: Bipe recommendation for a Ryobi 31cc
 

Hi,
A good running Ryobi 31 should fly it fine and the short nose wouldn't need extra weight,because the Ryobi ha s it built in at four pounds plus.

Dave

RE: Bipe recommendation for a Ryobi 31cc
 

Been planning on converting a WWI Stamp biplane that flew on a 4stroke 90 or 120, for well over a year. Got the engine mounted and also converted it to EI. I'm in the process of setting up the timing on the ignition so within a week or so I should have this installation completed. Plane has a 80" WS. The ryobi is attractive because of the narrow cowl but I have a quadra 35 on EI just in case the ryobi does not pan out.

RE: Bipe recommendation for a Ryobi 31cc
 

Yeah, that's my idea for the Tiger Moth type airplanes with a narrow cowl. The Ryobi fits without a big ugly carb (or muffler) hanging out the side.

It's ironic that this thread re-appears just now, as I'm working on a big Ryobi powered Tiger Moth from Nitro Planes. (www.nitroplanes.com) So far, it's like a match made in heaven. I'll try to get some pics posted in a day or two. The fuselage is all done except for mounting the cowl. That is going to entail no more than some massaging for the exhaust outlet tubes, a hole for access to the needle valves, and a hole for the choke linkage. Nothing will stick outside the cowl. It will be a bit before I do the test flight however, as I'm going to modify the wings to have four ailerons for better aerobatics. I don't have any illusions that this airplane will be an unlimited or 3D aerobatic with the Ryobi, but I am fairly sure it will have plenty of power for normal aerobatics such as loops, stall turns, etc. The plane itself is a steal for an ARF at only $200.00 bucks. It has a 76" wingspan, and looks very nice.

Later,
AV8TOR

RE: Bipe recommendation for a Ryobi 31cc
 

Tiger looks good, post a pic or two as soon as you can...here are a few pics of the Stamp Bipe.

RE: Bipe recommendation for a Ryobi 31cc
 

Need a ne paint job, anyone know of any schemes to this bipe? Thanks!

RE: Bipe recommendation for a Ryobi 31cc
 

something like this Les Manchot version of the SV-4B

http://users.pandora.be/sv-4b/Engels/v48.htm

i want to build one of these because of my wife loves penguins and she collects penguin stuff and the penguin motif would be kinda neat in her eyes.