Ryobi 31cc/Cost of convertion

How much does it cost to convert the engine to airplane mounting and stuff. I have the engine,but don't have a clue what to put it on.I'd
like to use the standard servos that I already have,radio also.Engine is still in the weedeater,so I have to start from scratch. Any sugguestions?? Thanx WAlt
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Usually you just have to examine the engine and see. Engine conversions don't have to cost much, if anything, you might need to fabricate some metal bits though. Here is some thoughts:
If you leave the clutch in, you should be able to disengage the propellor at idle (easy bellylander).
One thing that I've been considereing is a drive shaft pusher setup, probably a wing. The idea being that you can use a more efficient wing with less sweep with the motor in front, and the relative "safety" of not leading with the prop.
If you can saw your weedwacker off at the right spot and get a bearing and prop adapter on there then you can just bungee/zip tie/hoseclamp/hotglue/whatever the whole thing to your aircraft :) Of course driveshafts and clutches add weight :(
Try to keep the fuel tank in the same relative position to the carb.
l8r.

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Go to www.carrprecision.com and check out his kits. You can buy a conversion kit for about $55.00 or he'll do it for you.
TX snipped-for-privacy@webtv.net wrote:

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Or to....
http://www.ch-ignitions.com/#cat
or.....
http://www.jagengines.com /
or....
http://www.paragonaero.com/ryobi.htm
I converted one with CH ignition and jag mount/muffler, and another with just a prop adapter I got on Ebay........
Have fun.........
David
On Sat, 27 Nov 2004 08:28:08 -0800, Geoff Sanders

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TX snipped-for-privacy@webtv.net wrote in message

Do yourself a big favor and don't even venture into this. Unless you have a few hundred dollars laying around that you don't have anything else to do with. I, regretfully, went down this path... Motor mounts, muffler, ingnition, etc. etc. etc. I had the engine in a large Decathlon and it flew it ok but I wasn't completely happy with it. Pulled the Ryobi out, with all the junk associated with it and put an OS 1.60 in the plane. About half the weight and twice the power and a whole lot less trouble.
So unless you're completely bent on doing this I would suggest another path for your endeavor. If you MUST go to a gas engine, buy one already made for R/C. On the other hand, going through the process with the Ryobi was kinda fun and I learned a few things along the way. For me, it is now one of those things I've done, got the experience and moved on to something more practical. Do some math and figure out how many flights you'll have to make to offset the cost of what you're doing with what you will save in fuel costs. If you'd like me to answer any more questions you might have, please feel free to drop me a line.
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A few hundred??? Where do you buy your stuff, and can I sell it to you? I converted a Ryobi weedeater engine for about $5 of bar stock aluminum for the prop extension and a few hours of lathe and grinder work. The mount was already there, 4 bolt hole flanges on the back side of the crankcase. I had to buy a muffler, but I'd would have replaced the stock muffler on a R/C gas engine anyway. If you have access to a lathe and a little bit of machine shop experience, it's cheap and easy. The whole thing cost me $65 for the weedeater (sale at Big Lots), $5 for the Al barstock (local machine shop) for the prop extension, and $35 for the muffler (hobby shop), and $2 for 4 10-32 bolts and washers to mount it with (Home Depot).

Mine turned within a couple hundred RPM of a Zenoah G-23, the same size as the Ryobi. Response was good and idle was excellent.

Glow, huh? You must have mega bucks (as you say) "laying around" for fuel. For reliability, give me gas in the larger engines any day. No flameouts, reliable idle, almost no adjusting from day to day, easy starting, and MUCH cheaper to run.
Dr.1 Driver "There's a Hun in the sun!"
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snipped-for-privacy@aol.com (Dr1Driver) wrote in message

You didn't mention an ignition system which adds to the cost. Magneto is ok I suppose but adding electronic ignition sheds a lot of weight which is highly desirable with the Ryobi. As for the fuel, the 1.60 uses less than you'd think and it is safer. And no need to have a fire extinguisher available.
It's great that you converted yours so cheaply. But not everyone has access to a machine shop and if you have to pay someone for their machining it ain't gonna be cheap.
Bottom line is, if you do it right, it will cost more than buying an off the shelf engine ready for use, gas or glow. And if you're looking for any kind of performance glow will always have more power.
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methinks "do it right" is a highly subjective term. It may be that the fabrication involved is minimal. Perhaps the output shaft is already threaded and just the right bolt/spacers needs to be utilized and some sheet metal pop riveted into a muffler using the existing flange. The electronic ignition is a bit more challenging, but just as scratch building an airplane has it's rewards, so do all things that require a bit of ingenuity.
Steve.

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I have been wanting to try a gas conversion. have to motors already. wo
a 35cc motor on ebay fot 7 dollars and bought a ryobi leaf blower with 31cc and some guy heard that i was doing this little project a nd gav me a broken spline weed eater that started right up. now with thes engines they come in a varity of settings the Ryobi is the hardest t adapt because the muffler and the carb are located it the back of th motor making it difficult to mount in a cowl. its sticks out way t far. so i talked to the guy at WWW.Wackerengines.com . he told me tha the WEED EATER feather lites is the best. carb on one side muffler on the other and machined for light wight. an his parts are the cheapest ive seen. there like $30 for the self d conversion kit and $25 for a pitts muffler where else have you seen 1/4 or giant scale muffler for only $25 dollars and smoke system ready i will be putting one of these converted motors on my hanger9 25% Edg 540 as soon as it warms up here. hope this is another lead for all yo guys out there looking for the cheapest way to enjoy the hobby. He beats spending $499 for the same motor you can get for $100 to $150 Keep on flying and save money on GAS instead of Nitr
-- mtj4300 ----------------------------------------------------------------------- mtj43000's Profile: http://www.rcgroups.com/forums/member.php?action=getinfo&userid "43 View this thread: http://www.rcgroups.com/forums/showthread.php?threadid0341
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The RYOBI 31 works the best in acft, that have INLINE engines,,like theP40,,REARWIN SPEEDSTER ,, PT 19
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snipped-for-privacy@webtv.net wrote:

Why do you say that? The squat, almost square shape of the small gas engines like the Ryobi and Zenoah lend themselves perfectly to large, round cowls, like the Fokkers of WWI, and the AT-6s of WWII.
Dr1
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Back in November 2004, Walt asked the question of the cost of conversion of a Ryobi 31 cc. For my part, I have done this conversion and I have a great engine for less than $150.00 (less than half than comparable "model airplane" gas engines). With that said, I just read a review of the Zenoah G26 in the latest issue of Fly RC mag. Guess what? My weed cutter Ryobi conversion turns a 16x10 prop at a higher RPM (8,100 vs. 7,260) and idles lower (1,400 vs. 1,860) than the G26. And my tests are at 5,500 ft altitude with 15% thinner altitude, which knocks the crap out of engine horsepower.
As for weight my Ryobi is almost 1/2 pound lighter (51.1 vs. 58.3 oz.). I should add that I added a homebuilt electronic ignition and dumped the stock one pound flywheel/coil assembly.
Granted my $150 total cost doesn't include some of my labor and my friends machining (I owe him a lunch) and my 31cc is 22% larger displacement that the G26 @ 25.4cc.
Therefore my observation is that the engine conversions are at least comparable to other gas engines in their displacement class.

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