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-   -   Echo BME twin (https://www.rcuniverse.com/forum/engine-conversions-92/5422664-echo-bme-twin.html)

motorhd 05-28-2008 12:40 PM

RE: Echo BME twin
 
Let's keep this little twin alive. Perhaps someone would like to loan me one to reverse engineer or loan us the cnc file. This way a few of us could work together to make our own .
Jim 503-789-3420 [email protected]

Ralphbf 05-28-2008 12:57 PM

RE: Echo BME twin
 
PM sent to Motorhd

av8tor1977 05-28-2008 02:47 PM

RE: Echo BME twin
 
This thing was so popular, at one point I asked Keith at BME about the possiblity of doing another run of crankcases. He said that "In todays world, they would cost $200.00 a piece to have them made." Bummer!

AV8TOR

motorhd 06-10-2008 01:19 PM

RE: Echo BME twin
 
I have a converted 65 cc Stihl 4 stroke to trade for a small BME twin project .
motorhd

flyguyeddy 06-11-2008 09:02 PM

RE: Echo BME twin
 
boy thats tempting. can you mount it inverted?

motorhd 06-11-2008 09:18 PM

RE: Echo BME twin
 
The 65cc four stroke Stihl has no oil in the crancase so it wouldn't know the difference . Why don't you rmail your phone # and we can talk. My email is [email protected]
Thanks , motorhd (Jim)

Ralphbf 06-12-2008 01:04 AM

RE: Echo BME twin
 
Thanks Jim I'll ship out a crankcase to you tomorrow.

motorhd 06-12-2008 05:07 PM

RE: Echo BME twin
 
Thanks Ralph,
Jim

flyguyeddy 06-12-2008 10:32 PM

RE: Echo BME twin
 
damn! oh well i guess ill just have to finish this little project haha

av8tor1977 09-20-2008 04:17 PM

RE: Echo BME twin
 
Well, I have started on my BME 23.6cc STROKER twin. It is going to take a bit as I only have time to work on it a little at a time. I am using two 25cc cranks which have about a .100" longer stroke, and 23.6cc cylinders/pistons. You then have to make spacers to raise the cylinders up to accomodate the longer stroke. This allows you to easily set the deck height however, for optimum compression and performance. I will be porting the cylinders, etc., as well. I also need to come up with another reed valve assembly, though I have toyed with the idea of running two carburetors. Could be a real tuning hassle that way though, and take some of the fun away....

I have the crankshafts all modified and joined; just have to weld them now. LET ME TELL YOU, THOSE 25CC CRANKSHAFTS ARE HARD!! I flew through making the crank setup for my first twin with the 23.6cc cranks, but these 25cc cranks were a battle. At one point, I got too aggressive trying to cut into the surface hardness with a carbide bit in the lathe. The bit dug in, and CHIPPED THE BIT. You would think at this point the crank would probably be junk right? It didn't even nick the crank!! Anyway, it took some time but they are done now except for welding.

More as I get around to it...

Anyone have an extra reed valve assembly??

AV8TOR

flyguyeddy 09-20-2008 08:18 PM

RE: Echo BME twin
 
i wouldnt mind having a reed valve assembly either. im toying with the idea of making a manifold similar to that of the zenoah twins and just capping off the reed mount. would rather not do that tho, planned on this going into a piper cub and would much rather have everything on the bottom.


av8tor, do u still have the jugs for those 25cc engines? wouldnt mind taking them off your hands for my twin. i cant seem to find the 23.6 engines anywhere. (ive got 21.2 cc "R" type engines for my twin, but would much rather have more displacement)

Ralphbf 09-20-2008 11:26 PM

RE: Echo BME twin
 
Reed valves are not that hard to find.

I don't have extra but I was able to get 5 sets off e_ay for myself and friends.

It does take some looking, but they are out there for less than $15.00.

av8tor1977 09-21-2008 12:03 AM

RE: Echo BME twin
 
flyguyeddy... Sorry, but I don't have the 25cc cylinders and pistons. I bought just the cranks a while back from someone here in the forum. (It's been a while and now I can't remember who sold them to me.)

Ralphbf... Would you happen to have links or other sources you can share for those reed valve assemblies? Most everywhere I search says "no longer available."

Thanks,
AV8TOR

oldtimer2 09-21-2008 11:37 AM

RE: Echo BME twin
 
flyguyeddy..... I have a couple of 23.6cc engines, both have new cyl. & pistons. One is from a hedge trimmer so it has left hand threads on the crankshaft. The other is on the crankcase of a power edger 2400 with right hand threads on the crankshaft. I am not going to use them. If you are interested let me know. Later George

av8tor1977 10-06-2008 02:49 AM

RE: Echo BME twin
 
Hey, can anyone point me to the original post where Keith from BME offered the twin 23.6cc crankcases for sale?? I just searched for 45 minutes and couldn't find it.

Also, does anyone know what size carb Keith recommended for this twin?

Thanks!
AV8TOR

KI8FR 10-06-2008 07:19 AM

RE: Echo BME twin
 
Now I have to ask. Is this going to be a 23.6cc or is it going to be 47.2 when you are done with it?

Paul

tkg 10-06-2008 09:03 AM

RE: Echo BME twin
 
Its usually a Homelite reed block. No idea about where or PN.

av8tor1977 10-06-2008 12:16 PM

RE: Echo BME twin
 
1 Attachment(s)
That's two Echo 23.6cc cylinders for a total displacement of 47.2. However, the one I am working on now, my second one, has a longer stroke crank, and will displace about 50cc.

Thanks Terry. I know about the reed block. What I am wondering about is carb size, and I don't recall if Keith ever gave a recommendation on carbs for this engine. I have a 13.5mm carb on my first twin. I am thinking it would benefit from a larger, say a 15.8mm, carb.


AV8TOR

captinjohn 10-06-2008 04:58 PM

RE: Echo BME twin
 
AV8TOR, Where do you get the cap device that holds the glow wire to glow plug. Thanks Very much....Capt,n

av8tor1977 10-06-2008 06:00 PM

RE: Echo BME twin
 
It's called a "Head Lock", and is available from Tower Hobbies and others.

Here's a link: http://www3.towerhobbies.com/cgi-bin...ARCH=head+lock

Darn things are expensive! But for example on my Katana and my Fokker, it sure beats reaching under the plane with it running trying to disconnect a glow connector!! I only had to do that about one time before I knew I needed to make a change!! ;)

Hope you are enjoying your trip. It has finally cooled off some here in the desert, but I can't wait for it to cool off more!

AV8TOR

captinjohn 10-06-2008 06:48 PM

RE: Echo BME twin
 


ORIGINAL: av8tor1977

It's called a "Head Lock", and is available from Tower Hobbies and others.

Here's a link: http://www3.towerhobbies.com/cgi-bin...ARCH=head+lock

Darn things are expensive! But for example on my Katana and my Fokker, it sure beats reaching under the plane with it running trying to disconnect a glow connector!! I only had to do that about one time before I knew I needed to make a change!! ;)

Hope you are enjoying your trip. It has finally cooled off some here in the desert, but I can't wait for it to cool off more!

AV8TOR
The fall colors are great! The cold now rainy weather is not so great!!! Is is suppose to warm up a little. We can see Lake Superior, its always cold. In january we will be working at a camp in Florida. Hope its warm then. Best Regards Capt,n

buck1856 10-07-2008 12:18 AM

RE: Echo BME twin
 
You can find them at your local LHS.They might be in the Heli section as thats where there most commonly used.Ive used them in quite a few applications where neccesary.

motorhd 10-31-2008 01:08 PM

RE: Echo BME twin
 
My Bme 23.6 twin is about ready to test. I have an HDC48 11.3 mm or a HDC54 13.49 mm carb to pick from.
Which would be the best and is there anything special about HDC carbs that I need to know? Is there a better carb to use if I were to buy one? It will be gas gas glow.
Thanks Jim (motorhd)

av8tor1977 10-31-2008 10:05 PM

RE: Echo BME twin
 
I can't really advise you on the pros or cons of the HDC carb series, but I would recommend a venturi size of 13.5 or larger.

AV8TOR

captinjohn 10-31-2008 10:43 PM

RE: Echo BME twin
 


ORIGINAL: motorhd

My Bme 23.6 twin is about ready to test. I have an HDC48 11.3 mm or a HDC54 13.49 mm carb to pick from.
Which would be the best and is there anything special about HDC carbs that I need to know? Is there a better carb to use if I were to buy one? It will be gas gas glow.
Thanks Jim (motorhd)
Your twin...is it 23.6cc or 2 x 23.6cc 47.2cc? Just find a twin in production that is same cc and use that size carb they use! Capt,n


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