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-   -   ryobi 4 stroke weight (https://www.rcuniverse.com/forum/engine-conversions-92/3002593-ryobi-4-stroke-weight.html)

Dean in Milwaukee 05-23-2005 10:09 AM

ryobi 4 stroke weight
 
Got my harbor freight 26cc ryobi 4 stroker a while back, and finally had some time to begin fooling with it.

I stripped the heat shield stuff, the muffler, the flywheel and the ignition bracket and igntion save the spark plug, and got a weight of only 3lb 7oz. :)

This is much lighter than I would have guessed, the muffler itself being suprisingly heavy. I'm not yet sure if I want to go with a battery ignition, but it would save close to a pound of flywheel.

Performance at this point is hypothetical, but this motor is rated for 1 hp at 7k rpm, and the calc program I'm using says a 15x8 apc with 1 hp will turn 7600 rpm, so I'm going to assume a safe 7 grand rpm in real life, which should be about 7.5 lbs thrust and 54 mph pitch speed. A 16x7 should also work theoretically, making about 7200 rpm, 9.25 lbs thrust at 48 mph, but would require the motor to really make the full rated 1 hp at 7 k, not a tiny bit less.

I'm thinking the 15x8 will be enough to fly a 1/4 scale cub pretty realistically, but would appreciate anybodys thought on this.

Thanks,
Dean in Milwaukee

captinjohn 05-23-2005 03:13 PM

RE: ryobi 4 stroke weight
 
What kind of ignition are you going to use? Sounds like a fun experiment! J3 is a nice plane for that engine, I would think. Regards Capt,n

Dean in Milwaukee 05-23-2005 03:30 PM

RE: ryobi 4 stroke weight
 


ORIGINAL: captinjohn

What kind of ignition are you going to use? Sounds like a fun experiment! J3 is a nice plane for that engine, I would think. Regards Capt,n

Not sure who's ignition, have you any suggestions? Cheap is always good of course. As for the plane, I'm thinking perhaps the THE WORLD MODELS 1/4 scale clipped wing cub, probally in blue. Have to find out yet exactly how much its going to cost, but their 1/5th scale version is only $189, so I'm hoping it'll be pretty reasonable.

Dean in Milwaukee

captinjohn 05-23-2005 07:55 PM

RE: ryobi 4 stroke weight
 
Dean in M I bought a ignition from RCIGN1. I think its the best deal and he will fix it, if it ever quits. The price is right too.:D Capt,n

davewallace 05-23-2005 10:21 PM

RE: ryobi 4 stroke weight
 
1 Attachment(s)
Hi Dean,
I finished my Ryobi 4 stroke. It weights about 76 oz. with flywheel and coil ignition.I plan on trying glow fired E85 mix or regular glow, if I can make or buy a plug adaptor. The plug is special and very deep. I beam mounted the engine, so I can bolt it up to standard mounts. I havn't had a chance to run it yet, so I don't know how well it will run with the stock 9mm carb. The carb may be under jeted without the air filter. I took a couple pictures. I hope that this works, first time uploading.

Dave

captinjohn 05-24-2005 08:48 PM

RE: ryobi 4 stroke weight
 
Dave W: Sounds like that Ryobi 4 stroke is going to be neat on glow. If you can get a big glow carb that may be a way to see if its going to run good on glow. Good Luck.....Capt,n

foamcut 12-25-2007 01:39 PM

RE: ryobi 4 stroke weight
 
Dave,

Were you ever able to run the Ryobi 4 stroke on glow or gas / glow?

Thanks

davewallace 12-25-2007 11:52 PM

RE: ryobi 4 stroke weight
 
Foamcut,
I haven't fooled with the engines for a while. Teh very long reach special spark would make it very difficult to make a 10mm adapter. I thing EI would be the best ignition solution for weight savings. It would fire the plug every time. You will get ignition everyother revolution.

Dave


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