Can anyone identify this engine.
There is no name or identification on it as to maker or size.
The rear of the cylinder base says "Mahle"

It's about 7" tall and about 6" in length.
It has a Tillotson carb.

Any help appreciated

One of the very best RC engines ever...
3.7 or 4.2 Sachs Dolmar chainsaw conversion...
Look on the base of the cylinder...a 4.2 will have a 49ZN case into it, a 3.7 will have 47 ZN..
It will outrun and outlast any Chinese engine ever made...Maybe not in WOT rpm, but any other category.,.
1000 hours cutting down trees is normal for these....In the woods...Using whatever oil the lumbejacks had on hand...

Antique,
Thanks for the reply.
I was thinking Sachs because of the orange color.
There is nothing on the cylinder base except the letter "V" and "1 K" under that.

It pulled my 30lb plane around very well. I just have no idea what size it is.

Thanks again.

Wow !! A blast from the past as I believe that's one of mine. I converted Sach 4.2's primarily for B & B who sold most of them for me. They were a great engine with plenty of power and durability and I built over a 100 of them. The majority of engines built since then with machined cases used the Sachs cranks, rods, pistons and cylinders until recently as we're now seeing different and cheaper internals showing up.

Thanks for the additional info regarding size.

Do you happen to recall the size of the prop bolt?

Very good engines.. my father's 2T motorcycle was like this.

Sorry but I do not. Nowdays I seem to be lucky to find my way home almost every time.

Thanks anyway.
Found out it is 5/16-24
The nut from my TT 120 fits perfectly.

That engine should swing a 22X10 or 22X12 three blade with no problem. Sorry, I cant help you with two blades.

You're quite right.
It turned a 22x10 three bladed prop in the 30 lb plane it was in.
Easy loops from level flight.

I just didn't know what engine it was.

Down here we used to call them "Orange Case Sachs" The old A&M engines was started by a man named Al Willart who took the orange cases and cut the motors out, cnc a back plate, added a spring start, his motors had the chrome or polished mag covers, add a prop hub crank that baby up and go fly. The first motors were 3.1, then 3.7, then 4.2 I believe he did make some 5.8's. Loudest and heaviest motor this side of hades. I think the height of the Orange Case sachs craze was at Bryons flyins, where J.W. Jones took one of AL's motors mounted it in a Zirolli P-47 and cranked that baby up and flew pass after pass after pass down the runway and everyone just dropped their mouths open at the sound. This was the first time anyone heard a prop rip like we often do now. Those old orange case motors in one of the Bud Nosen or Zirolli big warbirds was the cats meow back then.

Just a little vignette of Texas RC History.

JDS

It's always good to remind people once and awhile that our foundation gas engines did not originate in China, Germany, or Arizona.

Anybody in this gasser stufflong enough know that ONE of the very first gassers came from just outside PHOENIX Arizona...It was a 28cc forerunner to the Ryobi....Sold by Hobby Lobby...Had mounting lugs just like a glow engine and came with a long cast motor mount and exhaust header..It couldn't be hand started and came with a rope and pulley for starting...
It was also sold as a gas powered drill....Had one of the first, can't remember how long ago it was...
The big sellers were Canadian Quadras and Japanese Zenoahs...Only the best survived..

...and the Canadian Quadra 42 became the US 41. I remember seeing my first gas engine back around '81 in a hobby store. They had a Zenoah and a Quadra. If I recall they were both around 20~23cc engines. I thought they were huge. At that time the biggest engine I had owned was a .61 glow.

Any chance some of you smart folks could help me figure out the size of this one? Other than some smudge blue ink, there's no markings that I can find.
Help?
Thanks!

It's for sure that it's a Sachs engine .You will need access to the face edge of the cylinder base flange to get the cylinder # . 44ZN is a 3.2 , 47ZN is a 3.7 and 49ZN is a 4.2 The numbers should be located just behind the flywheel shroud. You may need to unbolt the cylinder to raise it up enough to get to the numbers . I'm fairly certain its a 3.2 .

Thanks sir!
Odd to me that a manufacturer would hide their designators that way. I can easily pull the head on this one, but I have another buried in the nose of a 112" P-51. I'm not sure I want to go through that trouble to figure out the size.

Ah - OK thanks Truckracer. When CK1 said "face", I took that as the mating face between the cylinder and the crankcase. I think I get it now and will take a closer look. Much thanks!

The numbers can in fact be hidden from direct view on the OE version of the chainsaw crankcase .The OE case obstructs the front view of the cylinder flange face , unlike the r/c versions with which the numbers are clearly visible from the front of the engine

what chainsaws would look for to find one of these to convert ? I live where there are abundant logging equipment and chainsaw repair shops/dealers and they all have old chainsaws laying round.

Dolmer saw used the Sachs and Mahle cylinders
Dolmer 115i for the 3.2 and a Dolmer 120 super for the 4.2 .
Dolmer 133 for the 5.2 and Dolmer 143 for the 5.8

Hi,
I have a Sachs that looks just like the one Keefer posted. I verified it's a 3.7 and found a guy to rebuild the carb. I got a new spark plug but am not getting any spark. I think there may be rust on the magneto, but I can't figure out how to pull that shroud off the flywheel to get inside and take a look? Any ideas?
Thanks
Bernie

If like the one above, that engine appears to be an EI conversion as there is no visible mag coil. Maybe one of the ones that Ralph Cunningham did or something similar? The EI would appear to be behind that cover where the flywheel once lived. The cover should come off if you remove the prop driver hub. But just guessing as I haven't worked on that version Sachs before. Look earlier in this old thread and you can see the mag equipped version as the flywheel and coil are clearly visible.