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another darn ryobi post (ryobi performance modification, analysis and comparison)

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Old 05-11-2009, 05:18 PM
  #401
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Default RE: another darn ryobi post (ryobi performance modification, analysis and comparison)

I thought it might be the newer version. Funny how Craftsman called it a 32cc engine. I have several of the older versions in boxes that I have gathered over the last year or two. Since this crankcase has the mounting for the weedeater covers and fuel tank, it will require a lot of grinding to get down to size. I was thinking that I might take one of my short shaft crankcases with the bolt on type mounting and just modify the entryway for the transfer ports to match the one on the original. A couple minutes with the dremel should do the job nicely. I already have a prop hub for short shaft engine. Since I will be using electronic ignition, I will cut the center out of the the flywheel and mount the magnet to it. The hall sensor is mounted to the crankcase using a hose clamp with the sensor mounted to the clamp with 2-56 bolts with the heads ground down. I already have one Ryobi flying with this setup and it runs well. Flies my 14+ lb 4 star 120 with ease using an 18x10 MAS Classic prop.

This engine had noticably more compression than any of the other Ryobis I have had. Plus the exhaust port is not bridged. So this one should do well. I wonder if there are more of these floating around out there. My friend bought it only a year or two ago.

I have a set of plans for a 30" electric Miles Magister drawn in cad that I have enlarged to 80" that should be perfect for this engine.

Jim
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Old 05-11-2009, 10:17 PM
  #402
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Default RE: another darn ryobi post (ryobi performance modification, analysis and comparison)

Sounds like you got'r covered Jim....

If you're interested in doing some transfer port entrance smoothing ala post No 145 I'd be real curious whether it's worth the effort. When I did mine I just knew the stock blunt entrance to the transfer ports couldn't be good for the flow coefficient but I didn't actually measure the difference before and after the mods.

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Old 05-12-2009, 08:45 AM
  #403
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Default RE: another darn ryobi post (ryobi performance modification, analysis and comparison)

I can see what you are talking about with the blunt ends on the transfer runners in the head. What I was referring to was using an older style crankcase with a short shaft crank and modifing it ie. enlarging the opening for the duel runners on the new head. It looked like it would be easier to modify an older crankcase rather than machining off the outside of the newer crankcase. I will probably not convert this engine any time soon as I am still in the design stage of the Miles Magister that I want to put the engine into.

However, Your suggestion of smoothing the blunt end on the transfer port runners looks like it has merit. I would only worry about how the heat would affect it if it was too skinny.

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Old 05-12-2009, 06:59 PM
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Default RE: another darn ryobi post (ryobi performance modification, analysis and comparison)


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ORIGINAL: JIMARRINGTON

However, Your suggestion of smoothing the blunt end on the transfer port runners looks like it has merit. I would only worry about how the heat would affect it if it was too skinny.

Jim
I would think that area of the cylinder would run pretty cool what with the cool intake charge flowing by it and it being pretty far away from the combustion chamber. I only rounded off the blunt edges of the runners at the port entrance but did not touch beyond a few mm into the port.

It is true that there is only a little material that needs removing to match up the older crankcase with the newer bifurcated transfer port cylinder. Cutting away the integral fan shroud does take some time.

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Old 05-12-2009, 09:39 PM
  #405
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Default RE: another darn ryobi post (ryobi performance modification, analysis and comparison)

I got a chance to run and dial in my Ryobi 31 again today swinging an APC 18x6W. I was getting a good 6900-7000 RPM! I thought those were pretty respectable numbers for a stock unmodified 31CC Ryobi single ring with the Zama carb. I am running 89 octane mixed 40:1 with Klotz technoplate oil. It is the same oil I use to make my Nitro fuel and it is 80% synthetic/20% Castor. The Ryobi really seems to like it, but lawnboy ashless or Penzoil 2 stroke oil probably do just as well. The best reliable idle I could get was around 2200 RPM. I was hoping to get down to slightly under 2000, but 2200 probably be ok with a 6 pitch prop. If I was using an 8 pitch it might be hard to get the plane to slow down. Anyhow I just thought I would post my results. Now I just need a good day to take the Rascal out and test it in the air.[8D]

I just aquired another Ryobi weedeater, but this time it had the single ring 28.5cc short shaft Ryobi on it. I am in the process of getting it converted now, and will probably stick it on a Super Sportster 90/120 I am scratch building. This one has the Warlbro Carb instead of the Zama like my 31. Be interesting to see how the two stack up against one another.
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Old 05-12-2009, 10:22 PM
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Default RE: another darn ryobi post (ryobi performance modification, analysis and comparison)


Quote:
ORIGINAL: ckangaroo70

I got a chance to run and dial in my Ryobi 31 again today swinging an APC 18x6W. I was getting a good 6900-7000 RPM! I thought those were pretty respectable numbers for a stock unmodified 31CC Ryobi single ring with the Zama carb. I am running 89 octane mixed 40:1 with Klotz technoplate oil. It is the same oil I use to make my Nitro fuel and it is 80% synthetic/20% Castor. The Ryobi really seems to like it, but lawnboy ashless or Penzoil 2 stroke oil probably do just as well. The best reliable idle I could get was around 2200 RPM. I was hoping to get down to slightly under 2000, but 2200 probably be ok with a 6 pitch prop. If I was using an 8 pitch it might be hard to get the plane to slow down. Anyhow I just thought I would post my results. Now I just need a good day to take the Rascal out and test it in the air.[8D]

I just aquired another Ryobi weedeater, but this time it had the single ring 28.5cc short shaft Ryobi on it. I am in the process of getting it converted now, and will probably stick it on a Super Sportster 90/120 I am scratch building. This one has the Warlbro Carb instead of the Zama like my 31. Be interesting to see how the two stack up against one another.
If you make your own glow fuel, then you will have the ingredients to make gas/glow if thats your cup of tea. I think thats the only mod not covered. It would be kinda interesting to see the increase from stock gas to gas/glow, and modified gas to gas/glow.
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Old 05-13-2009, 02:49 PM
  #407
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Default RE: another darn ryobi post (ryobi performance modification, analysis and comparison)

Thats actually something I have considered and may decide to experiment with sometime. I like the cost savings associated with gas, but the Super Sportster might not be as receptive to the weight of the Ryobi as the Rascal is. So I may decide to shed some parts and ad a glow plug insert and do some experimenting someday with the glas/glow since I mix my own glow fuel and have the individual raw ingredients, but as of now I plan to just convert it for gas use like I did my other Ryobi.
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Old 05-13-2009, 08:39 PM
  #408
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Default RE: another darn ryobi post (ryobi performance modification, analysis and comparison)

I would really like to see a picture of the piston with the transfer ports cut in it. Everything you described on the craftsman 32 cc engine has already been discused here. the only thing i saw that you mentioned to be different was the piston with ports cut in it. the dual runner per side cylinder seems to respond well to the increasing the exhaust port timming as av8tor and diceco had had good luck with that mod on that type cylinder
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Old 05-13-2009, 09:37 PM
  #409
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Default RE: another darn ryobi post (ryobi performance modification, analysis and comparison)


Quote:
ORIGINAL: diceco


Quote:
ORIGINAL: captinjohn

Keep searching...and thow shall find!!! Capt,n
Sorry cap.... I'm not interested in playing your childish games....

diceco
With the NEW Search feature...it is easy for you or anyone to search. Give it a try. Capt,n
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Old 05-13-2009, 09:57 PM
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Default RE: another darn ryobi post (ryobi performance modification, analysis and comparison)


Quote:
ORIGINAL: captinjohn


Quote:
ORIGINAL: diceco


Quote:
ORIGINAL: captinjohn

Keep searching...and thow shall find!!! Capt,n
Sorry cap.... I'm not interested in playing your childish games....

diceco
With the NEW Search feature...it is easy for you or anyone to search. Give it a try. Capt,n
What the hell is wrong with you Capt,n? Why do you keep trying to stir the pot ? A couple guys are just having some friendly conversation and you have to come in here and try to stir things up. I am certain that within your 6000 post you have asked questions and said things that could be found elsewhere, but if a couple guys want to talk it up and share some ideas...then why in the hell do you keep suggesting they take there ball elsewhere? I am enjoying the conversation here on RCU...which is the main reason I come to RCU. There are lots of things I could just google without comming to RCU to find out, but I like to interact with other modelers and tinkerers. I also like to hear new ideas and new ways of doing things, and just because someone in a post 3 years ago said to do it this way does not mean it is the best way today! If you wanna just argue with someone...lets do it thru PM so other folks don't need to read thru this garbage and can enjoy the thread!
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Old 05-14-2009, 12:09 AM
  #411
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Default RE: another darn ryobi post (ryobi performance modification, analysis and comparison)


Quote:
ORIGINAL: combatpilot

I would really like to see a picture of the piston with the transfer ports cut in it. Everything you described on the craftsman 32 cc engine has already been discused here. the only thing i saw that you mentioned to be different was the piston with ports cut in it. the dual runner per side cylinder seems to respond well to the increasing the exhaust port timming as av8tor and diceco had had good luck with that mod on that type cylinder
Man i really wish i could have got an rpm from my engine. But removing the transfer ports doesnt cause any mechanical probs. I would really like someone to take over from where i left off. I would stil be tinkering with it, but the exhaust bolts backed out and rounded the holes, ruining the jug. I think the mod is definately plausable
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Old 05-14-2009, 12:13 AM
  #412
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Default RE: another darn ryobi post (ryobi performance modification, analysis and comparison)

About those exhaust holes.... Can you drill them bigger and re-tap? Next idea would be brass inserts or helicoil. Last choice would be having them welded shut and re-drilling and tapping. The reason I say "last choice" is because of the possiblity of warping the whole cylinder when welding it, though that might not happen....

AV8TOR
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Old 05-14-2009, 07:47 AM
  #413
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Default RE: another darn ryobi post (ryobi performance modification, analysis and comparison)

I was just looking at my engine, and it does seem like there is plenty of area around the bolt holes to retap some new holes if a guy needed to. Be a shame to have to pitch the jug over a couple stripped threads.
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Old 05-14-2009, 09:22 AM
  #414
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Default RE: another darn ryobi post (ryobi performance modification, analysis and comparison)

The piston on my engine does not have ports cut in it but has flat spots machined on the sides that match up to the transfer ports. I will see if I can get some pics in a day or two. Have to work little league concession stand tonight. woo-hoo! That is of course they have any games. We have been having monsoon rains here in Texas the last two weeks.

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Old 05-14-2009, 11:43 AM
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Default RE: another darn ryobi post (ryobi performance modification, analysis and comparison)

I tried drilling for 1/4" threads, which is as big as i could comfortably go. But the holes are oblonged (dont know how to spell it) I guess i could do the brass insert thing, where would i go about finding that kind of stuff. I would like to put the ryobi in the plane im building now (kinda looks like a bellanca scout) but it will likely be hard to find the stuff to fix it, and i only have limited acess to an actual shop.
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Old 05-14-2009, 12:22 PM
  #416
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Default RE: another darn ryobi post (ryobi performance modification, analysis and comparison)

JB weld in some 1/4-20 allthread studs after tapping, that should keep them in...
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Old 05-14-2009, 08:46 PM
  #417
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Default RE: another darn ryobi post (ryobi performance modification, analysis and comparison)

First I want to applogize to the guys that I said I would send some parts to. I still want to get that done I just have been so busy with work and work has been so crappy i have to do it.

Anyhow on the bad threads. i think the best idea for repair is to use alumiweld. it is kind of an aluninum brazing rod. I found it at harbor frieght and have tried it for welding together mufflers. it melts at somewhere around 750 degrees so it shouldnt ruin a cylinder. It uses a propane torch to weld with it.i think it has great potential to fill the holes to be re drilled and tapped. I would even be willing to try and do this repair for you if you like. I also have a tig welder and could go that route but i think the alumiweld would work good.

Unfortunatlly it may be next winter before I can get back to testing on this engine. It may be a good thing though as i really need the work right now lol.
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Old 05-22-2009, 06:26 PM
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Thought I would post my latest video of my Ryobi 31 running in my Sig Rascal 110. I am going to take the plane out for a flight tommorrow to see how it performs....so I thought I would make sure the engine was dialed in to where I was satisfied. Getting about 7000 rpm swinging an APC 18x6. Not awesome numbers, but should do fine for this plane.



 [youtube]http://www.youtube.com/watch?v=ftASjepWrz4[/youtube]



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Old 05-22-2009, 06:51 PM
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Default RE: another darn ryobi post (ryobi performance modification, analysis and comparison)


Quote:
ORIGINAL: combatpilot
i think the best idea for repair is to use alumiweld. it is kind of an aluninum brazing rod. I found it at harbor frieght and have tried it for welding together mufflers.
How did that work out? I have considered trying to make a couple mufflers just for fun. I bought a muffler from wacker engines for my Zenoah G38 a couple years ago, and that guy makes some real nice mufflers. I just thought I might experiment withtrying to makemy own sometime if I could find a good aluminum brazing product that would hold up to the heat and vibration.
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Old 05-22-2009, 07:03 PM
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Default RE: another darn ryobi post (ryobi performance modification, analysis and comparison)



ckangaroo70



I see your dog is like mine; the noise doesn't bother him.



Be careful with those full throttle runs on the ground, especially with a cowled engine.  It can overheat.  The engine is under less load and has more cooling air when it is flying.



Nice airplane!  I've always liked those.



How did you get the video right on your post?



Good luck on the maiden,



AV8TOR

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Old 05-22-2009, 07:17 PM
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Default RE: another darn ryobi post (ryobi performance modification, analysis and comparison)


Quote:
ORIGINAL: av8tor1977



ckangaroo70



Isee your dog is like mine; the noise doesn't bother him.



Be careful with those full throttle runs on the ground, especially with a cowled engine. It can overheat. The engine is under less load and has more cooling air when it is flying.



Nice airplane! I've always liked those.



How did you get the video right on your post?



Good luck on the maiden,



AV8TOR

My poor old dog has just gotten to old to care! She don't get to excited about anything anymore and she found my Ryobi project no exception. A trip to the post office in the truckis about the highlight of her day.

You are right about those full throttle runs, and I need to drop by Harbor Freight one day and pick me up a point and shoot temp gauge. However I like to share the noise with the neighbor whose dogs keep me awake at night!lol

Thanks for the compliment on the airplane. A snow birdfriend of mine gave it to me after he crashed it in Florida over the winter. He knocked the nose clean off of it, so it made the perfect candidate for a Ryobi since I could set the firewall wherever I wanted to help with the Ryobi weight. I set the firewall back 2 1/4" from its stock local when I rebuilt it. I actually maidened the airplane for the previous owner when it had a little XYZ 26cc engine on it. So I am kinda anxious to see how it compares with the engine that was in it previously. My buddy had a new in box Rascal 110 waiting for him here in Illinois when he came back this spring. He will be bringing it out to fly tommorrowas well. So should be fun to compare the two.

RCU has a new post editor. Perhaps you just hadn't noticed it since they just came out with it. I just hit the little youtube sign and then add my links between the youtube quotes.
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Old 05-22-2009, 10:20 PM
  #422
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Default RE: another darn ryobi post (ryobi performance modification, analysis and comparison)

hey, I guess if i could get a propane torch i could try welding the holes.  so is that aluminum rod like the kind for brazing? or is there a specific name for it?  I would really like to get the ryobi going again
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Old 05-22-2009, 11:09 PM
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Default RE: another darn ryobi post (ryobi performance modification, analysis and comparison)

Changaroo
What muffler are you using?
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Old 05-23-2009, 12:03 AM
  #424
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Default RE: another darn ryobi post (ryobi performance modification, analysis and comparison)

they have it at hardware stores, it's near the propane torches, usually comes in a tube of about 10 sticks for about $25
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Old 05-23-2009, 08:22 AM
  #425
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Default RE: another darn ryobi post (ryobi performance modification, analysis and comparison)

ckangaroo70, where do you go to fly? i live around pekin and have been past london mills several times to go to ingersoll.
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