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-   -   Conversion (https://www.rcuniverse.com/forum/engine-conversions-92/3466495-conversion.html)

joetsunami 10-18-2005 09:43 AM

Conversion
 
Can someone more familiar with these engines give me some guidance?

Are these conversions worth the trouble? Do you wind up with an engine that closely approximates the power and reliability available from DA or BME or others. Is the weight within reasonable bounds?

I'd love to do this, and would hate to spend the exorbitant amount of money I think the mfrs charge for their engines, but wouldn't want to end up with a dog of an engine......

Thanks for any info!

Joe

chris6414 10-18-2005 10:23 AM

RE: Conversion
 
I would do it for the fun of it. I started down this road about a year ago and am having a blast. My journey started when a friend gave me a slightly used Poulan chain saw with a 2.0 cu in motor in it (33cc). I already had one so, being an RC junky I figured I'd try to build one. I went the glow route as I found the magneto was attached to the case of the saw rather than the engine. If you stay with gas their are plenty of motors that have the magneto attached to the block. I spent $15 on an glow adapter and $20 on a prop hub and that is about all I've invested, other than time. My big bore glow motor will spin an APC 18-10 at 7800 and weighs about 2-3 lbs (a guess) with the stock steel exhaust. I still haven't built the big SPAD for it yet, but playing around with a motor that used to run on gas and now runs on Methanol or standard glow fuel is allot of fun. I even used the stock WT-324 with some slight internal mods to flow more fuel. It's definately much cheaper than a Fuji, DA or BME. The saws are really good for power but you can find some good weedy motors that produce good power. Have fun!!![&:]

tim220225 10-18-2005 01:24 PM

RE: Conversion
 
You will learn a lot and have fun too. I have been doing this a while. Mainly do Echo motors. Used weedeaters and such, but, I do their saw motors too. I do make my own hubs and timing rings but buy CH ignitions. Mufflers from Ken Lambert. I buy new saw short blocks and go from there. When you are done with the saw motor you have a BME 44 or 50. All my conversions have tons of power. Good luck.

smallplanes 10-18-2005 03:46 PM

RE: Conversion
 
Tim220225
How much does it cost you to buy the short block that makes a BME 50? Where could i fine the shortblock like you are talking about? I like to convert motors also and i've been wanting to do an echo.

Thanks
smallplanes

w8ye 10-18-2005 06:47 PM

RE: Conversion
 
Echo CS440 & Echo CS 510 power heads.

50cc is $190.00 from this site http://www.sepw.com/pages/13/default.htm CS-510 saw, ##SB1055 Block assembly

CS440 complete saw \/


http://www.mayberrys.com/echo/saws/i...003/cs-440.jpg

AnthonyH 10-19-2005 04:53 PM

RE: Conversion
 
1 Attachment(s)
The Echo CS440 is not the same engine that the BME 44 is. You need the Echo CS 4400 for that. The CS440 has a two piece crankcase and one piece jug. The CS4400 is like the Poulans in that it is a two piece engine. Here are the pics.

If you want an easy and cheap conversion that makes good power try the Poulan 46 or Homelite 45. Both have lots of info about them on here and you can get them from small engine shops for little to nothing. There are several guys who make the needed conversion parts at a reasonable price as well. I just did a Poulan and I have a total of $58 in it and that includes the Hangar 9 mount.

Steve Sanford 10-20-2005 09:12 AM

RE: Conversion
 
Those echos are good engines, (Koritz)I have, what I remember being the 42cc version of that one, turns a 20-8, and 18-10 at 8000 with the standard mag ignition advanced 4 degrees, different muffler, and velosity stack, this was taken from a chainsaw with a wore out clutch, lots of use on it, still runs great. SS

smallplanes 10-20-2005 11:30 AM

RE: Conversion
 
AnthonyH
I have a poulan 46cc that i converted,it has CH Ign. on it and it seams to be a great motor. I have it on a 28% Texas Hurricane and Friday will be the 1st flight on it. I hope it does good. I had it mounted on a scratch built somethin extra(around 30%) it weighed 18LBS and it did ok but it would not hover the plane. I got a bolly 20x8 prop on it i also made my own muffler,prop hub,and carb mount. The motor will crank on the 3rd swing almost evertime but for some reason i can get it to turn no more than about 7100rpms not sure why. I just wanted a motor with just a little bit more for the sometin extra. O yes how do you think the Texas Hurricane with the 46 on it will do? The hurricane weight is about 15lbs ready to fly.

Thanks
smallplanes

zx32tt 10-20-2005 12:20 PM

RE: Conversion
 
The TX Hurrican and Poulan 46 are a great combination. I was able to get 7000rpm on mine with a Menz 20-10. I think a 21-8 might be a good choice also. The landing gear on my Hurricane was replaced with one from a GP Patty Wagstaff Extra. I would highly reccomend replacing or at least regluing the engine firewall.
Z

AnthonyH 10-20-2005 01:50 PM

RE: Conversion
 
As Z said, the Poulan 46 should be great on the TX Hurricane. I have mine going on a Robinhood. It has a MenzS 20x8 for starters. I will try the MenzS 20x10 as well. The Robinhood is my aerotow/candy drop/parachute drop plane. My initial run of the engine on the 20x8 was in the 7100rpm range. I am sure it will get better once the ring seats.

smallplanes 10-20-2005 05:16 PM

RE: Conversion
 
Well maybe my ring has not seated good yet i will have to give it a little more time. I'm running Amsoil 80:1 in mine. Will the 46 hover the Hurricane? I drilled a pined my firewall and put a tin layer of epoxy over it. Do you think i need to put some support in the landing gear blocks inside the plane?

Thanks for the info guys
smallplanes

zx32tt 10-20-2005 07:48 PM

RE: Conversion
 
As I recall, the landing gear mount is ok, its the gear that is flimsy. The motor box needs to be boxed in and hardwood triangle stock added. The plywood used for the structure is not aircraft ply, and delaminates very easily. Just pinning the the firewall ain't gonna help much.
Z

tim220225 10-27-2005 10:00 PM

RE: Conversion
 
1 Attachment(s)
Smallplanes, I get my engines, carbs and parts from online stores like SEPW above. Between 170 and 190 for a short block. You can also get the smaller weedeater motors from Echo at these stores also. The hubs and such I make myself. I use CH igniotions in my conversions. If you take the cost of the ignition out you have around 250 in a 50cc motor. In my case I have an ignition for each motor but you could just swap the box between motors to save money. Not too shabby I would say. Here is a picture of my 44cc being setup in a Wildhare 1.20 size Edge for my son.

smallplanes 10-28-2005 03:25 PM

RE: Conversion
 
Your hub and set up looks very good. Could i see a pic of your hub from the side? I make my own hubs to but not like the way you made yours. What carb do you think would be a good one for my poulan 46? The guy from CH Ignitions says a WT-76 would be a good one for this motor.

Thanks
smallplanes

davewallace 10-28-2005 04:23 PM

RE: Conversion
 
Hello,
You want a Walbro with a 34 cast into the venturi inlet. This is a 13.49mm carb.

Dave

Antique 10-28-2005 08:20 PM

RE: Conversion
 
Great copy of a BME hub;)

mikenlapaz 10-29-2005 04:54 AM

RE: Conversion
 
I like your hub also. A side shot would be nice with any tips you would care to share.


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