I scored an engine I didn't even know existed. An Echo 30cc from a string trimmer I believe it is. We have an Echo/Stihl dealer that let's us go through his junk pile of engines and sells them to us, and we've really done well at it. This engine wasn't in a machine; just lying on the ground all by it's lonesome. It is the same basic size and shape as the Echo 21 through 26cc engines, but it is 30cc.

I'm excited about it as I think it will make a nice, lightweight, powerful conversion engine. I have one Echo 30cc from a chain saw, but it has a crankcase mounted reed valve intake. I have another from a different chainsaw, but it has to have the crankcase cut out of the saw and a backplate made for it. This one is "slam bam, thank you ma'am" easy to convert just like the other smaller Echos.

Anyway, here it is in all it's (dirty) glory. I pulled the muffler off and it looks great inside!

AV8TOR

Wow,that IS sweet! Trade you one of my girlfriends cats for it?

Man, how embarrassing!! [] FALSE ALARM. I just took it apart and measured it and it is a plain old 25cc engine. I thought the cylinder looked different than the 25cc engines I have, but after getting it apart I see that it is not, and it measures out at 25.4cc.

Oh well, I'm bummed....

Hey wait, I wonder if I can make my other 30cc Echo pieces fit into this crankcase? I'll have to look into that.

AV8TOR

What is the stroke on the engine you just took apart? If it is the same bore as the one,s you have, to be a 30cc engine the stroke would need to be longer. There is a web-page with all that data. I will take a look also. Capt,n

It measures out to be 25.4cc.

The formula I use because it is easy to remember is: (bore x bore) x stroke x .7854 = displacement

Bore is 1.339"
Stroke is 1.10"

(1.339" x 1.339" ) x 1.10" x .7854 = 1.55 cubic inches.

1.55 cubic inches divided by .061 to get cc's is 25.4cc

AV8TOR

(EDITED to correct bore size)

Ya it's no good-send it to me and i'll dispose of it for you.

Tell me what I am doing wrong

1.39 x 1.39 = 1.9321 x 1.10 = 2.12531 x .7854 = 1.6692 divided .061 = 27.36

What am I doing different

Thanks
Milton

HHMmmm! Very interesting indeed!!!! I am sure someone will chime in on this one. Gotta go up North right now....C YA Later. Capt,n[X(]

My mistake. I mis-typed the bore size. I just edited the post to correct it. I had 1.390" for the bore when it should have been 1.339".

Funny how my error just happened to make it closer to 30cc heh?? Oh well...

AV8TOR