av8tor1977

My Feedback: (6)

Yeah, you lost me too. It has to have a reed valve or it won't run. It is not a piston ported engine.

AV8TOR

spaceworm

Quote

Tim
If your back plate is 1" thick, then machine it so the reed block from a DLE 30 fits. The reed block would also be your heat dam.

_____________________________

TKG
To much power is just about right.
quote

TKG addressed this issue some posts back. I lost track of it after that and just thought the DLE 30 reed block was going to be used.

av8tor1977

My Feedback: (6)

That was a very good suggestion by TKG. It would be interesting to see what the power gain would be with the much better reed valve/induction system as well.

AV8TOR

w8ye

My Feedback: (16)

This would be neat on a Ryobi? I'm wanting to see someone do it!

They are out of stock at Tower but are $14.99 http://www3.towerhobbies.com/cgi-bin...?&I=LXAACW&P=Z

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tim220225

My Feedback: (4)

I spoke to the guy at JAG engines and he indicated it didn't matter which system I used. Oh well you learn something every day. I can adapt this back plate easy enough. Just a little mill time and all will be fine.

av8tor1977

My Feedback: (6)

Hmmm, must have been either a misunderstanding or else the guy didn't know what he was talking about. No two stroke engine with the carb mounted on the crankcase will run without either a reed valve or a rotary valve.

Keep at it, it is a neat project.

AV8TOR

w8ye

My Feedback: (16)

"Carb mounted on the crankcase"?

tim220225

My Feedback: (4)

OK guys I ordered the DLE insulator and reed assembly today. $15.00 is more than fair I think. As soon as I get it I can mill the case to fit the reed assembly and post pictures when I do. Also pressed the wrist pin from the piston just to see what it is. Looks like you could make a rod if you had the gumption but the stamped one still looks fine to me. This engine won't turn much more than 7200 with the 16/8 APC prop I want to use.

w8ye

My Feedback: (16)

I can hardly wait to see the results

It should run pretty fast with a 16 X 8 with a 11.11 mm carb and a diamond reed assembly.

You will have to run a 18 X 8 to keep the rpms in the mid 7's

tim220225

My Feedback: (4)

Time will tell on the performance. I have only used reeds on one other engine and that was the old Echo twin chainsaw. Don't really know much about the setup but I will learn the differences. Performance I expect was based on JAG engines information which may be off a little, maybe it was my mind. Oh well. An 18/8 may be a little tall for the 4 Star 1.20 with stock landing gear, again time will tell. I have a WT-289 on tha bench now which is 11.11mm, I have several others the same size. Getting to the choke will present another challenge since I am running a cowl on the plane.

w8ye

My Feedback: (16)

A 16 X 10 is another good prop for them. I have a ryobi with the stock #20 Walbro carb and it turns a 16 X 10 at 7000. I always assumed it would be up around 7500 with an 11mm carb?

av8tor1977

My Feedback: (6)

Yeah, that was supposed to be "carb" mounted to the crankcase of course. I just edited it.

I think you are going to have more power than you need for this ariplane/engine setup, and it will be very interesting to see your rpm numbers when you are done. You can always use the throttle stick as far as the power is concerned, but your problem is as you said; prop clearance. Like W8YE said, you could go to more pitch on a 16" prop, but then they are a bit tough to slow down on landings. Maybe add flaps or flaperons...

The only Ryobi I am running at this time is on my 76" Tiger Moth biplane. It has electronic ignition, 150 degree exhaust port timing, 11mm carb, and an aftermarket two tube muffler. Turns an 18 x 6 at 8000 plus. I never run it at full throttle 'cause I don't want to blow it up. I might try a 20" prop on it someday, but the problem is the spinner is smallish to accomodate large props.

Keep us posted on yours Tim. Neat project.

AV8TOR

tkg

My Feedback: (1)

Graupner makes a 15x8 and a 16x8 3 blade prop. They are a heavy load so they should keep your Ryobi from over reving.
See Hobby Lobby for information

tim220225

My Feedback: (4)

Well I got the reed assembly for the DLE 30. Still not sure I want to go this route. I have to bore almost all the way through the backplate I made to get the reeds to extend just inside the backplate. Looks to me from looking at the DLE pictures that the screws go all the way through the backplate they provide. I may try to install the stock reed on the backplate to test that setup first. Any thoughts?

w8ye

My Feedback: (16)

To utilize the DLE type reed block assembly, you may have to completely re-think your Ryobi back plate design so as to not shroud the reeds?

This will possibly be a compromise of crankcase minimum volume and breathing ability?

captinjohn

<hr />by who....Oh well ...I suggested it too! Why not go for it? Capt,n

av8tor1977

My Feedback: (6)

Yeah, you too Captain John!

AV8TOR

av8tor1977

My Feedback: (6)

Personally I would have to try to find a way to make the better reed assembly work. I think it would be worth it, but then I'm a hot rodder from way back...

AV8TOR

tkg

My Feedback: (1)

By all means try the Ryobi reed, the machine things for the DLE reed and see what is more important. Breathing or crankcase volume

tkg

My Feedback: (1)

UPDATE???

Scota4570

Nice work. It was very close to a rotary valve. A rotary valve disk in the plug that went in the crankcase would be interesting. Spin it with an extended crank pin?
It would be interesting to see how different inlet timings would work out. One might consiter a stouter, and possibly longer wrist pin. The piston could then be domed for higher compression. Since the exhaust port is off the back a tuned pipe would be straight shot. It would be interesting to see how much it could be pushed.

JIMARRINGTON

I fly a low power Ryobi on a 4 star 120 using a MAS 18 x 10 and rcexl ignition. Runs great and is perfect power for the airplane. Granted this airplane has been around a long time and is heavy for having been repaired several times. AUW is 14 lbs. It was given to me by another club member and has become one of my favorite planes to fly. Right now it is the ugliest airplane you have probably ever seen but for some reason I always land with a smile on my face. I do have to be careful with landing because if I bounce too much it is possible to have a prop strike.

JIm

tim220225

My Feedback: (4)

Jim did you do any firewall modifications to the plane? I have a cowl for mine and am concerned about balance. Others have moved the firewall back. I plan on using a tail mounted rudder servo to help balance.

Tim

JIMARRINGTON

I could not tell you for sure as the plane had been repaired a few times before I got it but the firewall appears to be in the stock position. The servo for the throttle is right behind the firewall. The fuel tank is on the CG. The other servos look like they are in the stock positions. I have a 6.0 volt sub c nicad pack for servo power and it is mounted at the rear of the wing bay area. nothing is in the back. The cheeks that normally surround the engine on my plane are missing so the engine just sticks out there from the firewall. The canopy is missing and the covering is tacky to say the least. Like I said, it has to be the ugliest 4 star out there but I am going to go fly it this afternoon. BTW I do not even think the Ryobi is giving me full power because I have never been able to get a good tune on the high end needle nor will it peak out at full throttle. But it flies well like it is. Right now I am scratch building myself a giant ugly stick that I plan on taking this motor off and reworking it and using on the ugly stick. In my opinion, a ryobi is a good choice for a 4 star.

Jim

av8tor1977

My Feedback: (6)

One time a Ryobi of my brother's wouldn't tune. It always sounded like it was four stroking at high throttle no matter how you tuned the carb. I finally pulled it apart and found the back plate cracked, right through the reed valve seating area. I installed a new plastic backplate, and then it ran perfectly. That plastic backplate could easily be cracked in a crash, and/or if the engine was ever dropped on the floor.

AV8TOR