don't forget echo! (Full Version)

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ZAGNUT -> don't forget echo! (5/24/2003 5:06 AM)

volfy is right about the gas vs. glo issue. i simply can't see this engine weighing any less than the other echo trimmers. where i live gas costs nearly $4 a gallon because of taxes so i'm also looking into methanol as an alternative in the trimmer engines.

if you keep the mag you can leave the coil in place no problem, don't worry about the cooling. the ignition in these engines is CDI and similar to what is used on zenoah, i'd say the voltage to the seperate coil is 200-400 volts. CH makes ignition kits for zenoah that utilize the original oem coil and cost a little less so they might be able to set you up with something that wont break the bank.

also, looking at [URL]http://www.echo-usa.com[/URL] i see that the max rpm for this engine is 7000 so this should help with your prop choice.

dave



BME -> Dont forget Echo (5/28/2003 11:36 AM)

Zagnut

I have tried what you said but found the compression loss is more important than the transfer time. I find it didnt work for me. You also have to keep in mind that the mods I mention increase the blowdown time to increase performance. If I did anything to inhance tranfer time area it would be to add two boost ports opposite the exhaust. This would require you to use a reed valve in the crankcase though.


Keith
BME



ZAGNUT -> don't forget echo! (5/29/2003 1:45 AM)

thanks for the tip keith. i guess i'll just try playing with the compression and exhaust timing and see what happens, just need to find the time. still haven't come across a 23.6cc yet, do you know if it was offered on any other brand of equipment?

later,
dave



Volfy -> don't forget echo! (5/29/2003 12:53 PM)

I looked through the current Echo catalog and found only one item using the 23.6cc block - an obscure engine drill, IIRC. A whole bunch of 21.2cc and 25.4cc, with a few 22.8cc.

The 25.4cc Kioritz or Zenoah/Redmax should do just fine for my small block gasser needs. Anything larger and Poulans become more cost effective.



mikenlapaz -> don't forget echo! (5/30/2003 12:11 AM)

Thanks Volfy.
Was the 23.6 ever used on weedeaters? I keep looking at weedies for this size engine and if they did not use it for that purpose I'll modify my search.



av8tor1977 -> don't forget echo! (6/2/2003 4:12 AM)

Does anyone think I'll be able to get 7000 rpm's on an APC 15 x 8 with my little Kioritz 16cc on gas? With a little hopping up maybe?

Appreciate any comments.

Thanks,

AV8TOR



av8tor1977 -> Hacking away at it... (6/4/2003 10:35 AM)

Here is a couple of pics of my Kioritz 16 cc project. The prop bolted right to the shaft where the mag was with nothing more than a couple of washers. The shaft is not tapered, and this couldn't have been easier.

The second shot is of the rear "bell housing" area, where I am going to put the ignition. I will make an aluminum collar about 1" in diameter to place on that shaft to mount the magnet.

Hey, does anyone think I have a shot in hell of getting this little guy to turn an APC 15 x 8 prop at 7000???? I am not opposed to hopping it up if necessary. I measured the squish/quench area and it is .045". Not a lot of room to shave the base of the cylinder for more compression with that kind of a quench measurement. Any inexpensive sources out there for a larger carb for this engine? $38.00 for a carb seems a lot when you can buy a whole weedeater for around $55.00!!!

Thanks,
AV8TOR



av8tor1977 -> don't forget echo! (6/4/2003 10:37 AM)

PHOTO NUMBER TWO, THE BACK SIDE.

AV8TOR



ANeat -> don't forget echo! (6/4/2003 12:03 PM)

Im interested in what you get out of it. Ive got one of the 16cc engines I may get around to converting some day. :rolleyes: Ive got to many engines!!! I need more planes :D
Adam



av8tor1977 -> don't forget echo! (6/4/2003 1:27 PM)

Yes, I'll be sure to let everyone know how it does. In some testing, I found out that my old non-schneurle Fox .78 makes a little less power than a decent modern .61. I'm thinking the little Kioritz can equal this in thrust, if not stock then with some mods. I've asked a few times in the forum what people think it will turn, but nobody has really answered me. Perhaps nobody knows!! It is pretty light, and I'm going to use CH ignition instead of the mag. The old Fox hauls my custom low wing Big Stick around pretty well, so we'll see how it does with the Kioritz....

Later on I'm going to convert the Big Stick to a Big Stick Biplane, so I'm really not going to be worried about weight then! I've already ordered the stuff to do that project, but I'm going to fly it as it is with the Kioritz for comparisons sake.

Thanks,
AV8TOR



Volfy -> don't forget echo! (6/4/2003 9:52 PM)

AV8tor, what's the weight of your 16cc short block as shown in your picture (minus the prop, of course)?

My guess is that since its displacement is about .97 c.i., it will probably make about the same power as a good .61 2stroke glow engine. I'm sure it will have enough pull for your Stik. The only question might be in rebalancing the plane.



av8tor1977 -> don't forget echo! (6/5/2003 2:49 AM)

My cheap, but new, fish spring scales says 2 lbs. exactly. (I have a digital scales on order!)

On the weight side of things:

I won't be using an engine mount, just mounting it straight to the firewall with those 3 screw holes on the back.

As you can see, I'm not using a prop hub, so that saves, and the little collar I am going to make for the ignition magnet in back will weigh almost nothing.

I have ordered a lighter weight NiMh battery pack for the ignition.

I will be using an 8 oz. tank of gas instead of a 16 oz. tank of glow fuel. Someone, I think Zagnut, mentioned that gas is lighter than glow fuel as well.

I'm working on making up some kind of an aluminum muffler for the gasser as well. At the very least I will gut the stock one completely.

All in all, I don't think I will effectively gain much weight with the plane. I will of course, check the balance carefully. This plane flies/is trimmed perfectly and I don't want to change that! (Does cool Lomcevaks!) I have a gut feeling that this is going to be a very nice conversion/combination. I just wish I could find a larger carburetor on the cheap!

Thanks,
AV8TOR



av8tor1977 -> WHOOPS... (6/5/2003 3:28 AM)

I misread the part; what is the weight "without the prop" and just ran out and weighed it WITH the prop. Just for mocking up, it has a Master Airscrew 13 x 6 on it, so deduct the approximate weight for that off what I sent to get the correct weight. Once again, this is with a cheapie spring scale. I will send more "weights" as the project unfolds, and when I get my new digital scale.

Thanks,

AV8TOR



ANeat -> Cheap carbs (6/5/2003 3:58 AM)

For cheap carbs there are a few guys selling them on EBAY. I bought quite a few from one guy on ebay. He was selling them 15 at a time. They were all assorted Walbro carbs, no choice but he happened to be located close to me so he let me come and pick through them. :D
AV8tor; Try your carb that is on it, Ill have to get out my 16cc Echo and see what size it is, Ive got a bunch of that stuff and I should be able to find something that will work. It will be interesting to see how big is too big.
Adam



av8tor1977 -> don't forget echo! (6/5/2003 4:38 AM)

Hi and thanks,

Here is a pic of the little carb. It is a Walbro #138a. It is very tiny with a bore of .278". My .61 glow carbs have a much bigger bore! I'm sure it could use a bigger carb, and everyone seems to gain power with these things with one.

As you can see, it has an annular cast ring in the bore. Doesn't look like I can enlarge this, as this is where the metering holes are; one vertical and one horizontal. Don't want to get into those!

If you have something I could use, that would be great! I have a mailbox in the states 60 miles from here that I use. (I'm in Mexico) (See the thread "something to be jealous of guys".

For everyone's information, to do pics of small things, I just use my scanner! Works great! The engine pics came out a little dark, so I just used a white t-shirt as a cover to reflect the light.

Thanks again,
AV8TOR



ANeat -> Carb info (6/5/2003 5:26 AM)

What are the letters before the number, should be a WT, WA or something.
Adam



av8tor1977 -> don't forget echo! (6/5/2003 7:00 AM)

Hi,

It has a "WA" above the number "138A".

Also has an "A5" stamped on it down in the corner from there.

Thanks,
Bob



ANeat -> don't forget echo! (6/5/2003 7:22 AM)

Hmmmm; A WA138 is supposed to have a 11.11mm venturi per here http://wem.walbro.com/walbro/family2.asp
That seems larger that what you have described, 11.1 mm should be approx .437 inch.
Adam

This link will take you to the WA138 http://wem.walbro.com/walbro/product2.asp?Series=WA&partnum=WA%2D138%2D1



av8tor1977 -> don't forget echo! (6/5/2003 11:11 AM)

Hi,

Thanks for the Walbro links. I had them a while back, but lost them.

Well, there's two possibilities here. One, perhaps that "A" suffix means something. I didn't see an "A" suffix in those listings, and there is one model WA-138 that is says is unavailable and has no listing for the venturi size.

The other, and more likely possibility is this: My "venturi", or carb throat, actually does measure around 11.5 mm, but that annular ring you see in the picture where the metering holes are is .279", or about 7 mm. It's not going to flow any more than the smallest area, so that's what I measured. I cleaned up a small casting ridge in that ring, and gained a few thousandths, but I was afraid to go any more. It now measures .282". The screw mounting the butterfly valve to the shaft was too long and obstructing flow, so I carefully ground it down too. I think that's as good as this little puppy of a carb is going to get!

Now I'm working on gutting the muffler, and it is the only part of this project that has not been fun. What a pain! If I lived in the states and had access to my welders it would be easier, but then I would never fool with the stocker; I would build one out of aluminum!!

Thanks again,
AV8TOR



av8tor1977 -> Nope, here's the answer... (6/5/2003 11:23 AM)

Hi again,

Here's the web page for my trimmer: http://www.echo-usa.com/oot/docs/GT160_080182.pdf

Then here's the page for my carb: http://wem.walbro.com/walbro/product2.asp?Series=WA&partnum=WA%2D123%2D1

It says 7.14 mm; just what mine measures.

Got anything bigger for a reasonable price that will fit and work?

Thanks,
AV8TOR



ANeat -> don't forget echo! (6/5/2003 12:03 PM)

Well Ive got a bunch of assorted sizes, I would recommend you try the stocker first. I was doing some looking and the stock carb on one of my Ryobi 31cc engines is a WT26, 7.95 mm venturi. Everything else I have is bigger, 11.11mm and larger. If one of the larger ones I have works on the Ryobi I could sell you the carb off the Ryobi.
I dont think the 11+ mm venturi carbs would work well on a 16cc engine??


Thats wierd about the mix up on the carb numbers, Ive got the same engine, Ill have to dig it out and see if the carb on it is marked the same way??

Adam



av8tor1977 -> don't forget echo! (6/5/2003 8:40 PM)

Yeah, the only thing I can figure is the carb got misstamped. I'm going to run everything stock; compression, port timing, and carb, to get a baseline first. I've already gutted the muffler, but then I noticed that it is going to be too large/close in a few spots in my application so I will probably make a better muffler for it though. I already have some ideas for one. If it will make enough power to equal or better my old Fox .78, I'm going to fly it as it is for now. First change if I need more power I believe would be the carb though.

Thanks for the help!

AV8TOR



kevin28 -> don't forget echo! (6/5/2003 9:33 PM)

Does anyone know if echo makes an engine that has the plug vertical. I have an echo i want to convert for a boat, but it makes it more complicated with a slanted plug.

Thank you
Kevin



av8tor1977 -> don't forget echo! (6/5/2003 11:58 PM)

Hi,

I don't know about a vertical plug. Keith at BME knows a lot about these engines. Check these threads for his posts and e-mail address.

Mine came with a centrifigal clutch. When I saw that, I thought how cool it would be for a car or boat, with the clutch!

Have fun,
AV8TOR



Volfy -> don't forget echo! (6/6/2003 12:21 AM)

Don't know about older Echo engines, but most of the current production smaller Echo engines are all slanted plug. You might try looking for Redmax/Zenoah engines instead. Their small engines (22.5cc and 25.4cc) are very similar to Echo's but have straight plugs. I think the smaller Sachs or Quadras are also straight plug.

Don't know if you're wanting specifically a higher-grade dual counterbalance, dual BB engine, but many of the cheaper weedies like Homelite, Ryobi and McCulloch are all straigh plugs. Boat and car applications are not quite as weight sensitive as RC airplane apps, so these "homeowner-duty" weedie engines should work just fine.



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