Prototype Opposed Piston Experimental Chainsaw Engine by Mall Remington Arms

Est. 1950 Mall-Remington experimental/prototype chainsaw engine
Opposed piston design
2 crankshafts, 2 pistons & 1 cylinder
2 stroke, requires oil/gas mix
Both cylinders & middle head are one casting
Designed from 2 saws that Mall/Rem produced at the time. 1 cylinder is from a GL7 direct drive saw, and the other is shared from a GL7R gear or belt drive saw. This was required because the engines mirrored each other, making it simple to design because both intake & exhaust ports were on same side as each other.
This engine has a displacement of almost 13 cubic inch (210cc)
6.5 c.i. (105cc) multiplied by 2
Both the GL7 & GL7R saws were 6.46 cubic inch (105cc)
Bore 2.25 in (57mm)
Stroke 1.625 in (41mm)
Engine runs well, ignition coil was bad. I substituted with a 6v battery ignition & a Rowland RMC coil out of New Washington, Ohio
The engine was thoroughly inspected, serviced & identified by Larry @ House O Saws in Litchfield, Ohio. World known chainsaw collector of 7000+ chainsaws.

[@Circlotron]

Would have even less vibration if the flywheels were the same mass and rotated opposite directions. The instantaneous torque going in and out of each flywheel would match so there would be no rotational "vibration" around the axis of each crank.

[@gavmansworkshop5624]

Only a company ran by folks like you and me would start doing Garage54 stuff on the side like this. I love it 👍

[@arnokilianski7889]

I love the way it's just c-clamped to a workbench, with no silencer. Thanks for posting. In the mid 1980's, I worked with Fairbanks-Morse dual opposed piston diesel engines in the Canadian coast guard. Similar layout, but of course way bigger, and vertically stacked as opposed to horizontal.

[@Oufg103f]

Awesome 👍

[@jlo13800]

Now Cummins makes the OP ACE 2 stroke. How about a KX1000 OP 2 stroke made from 2 KX500 engines. Thats would be one sick dirtbike

[@akbarshoed]

Fan. Frickin. tastic

[@jlo13800]

mart.cummins.com/imagelibrary/data/assetfiles/0058689.pdf

[@akbarshoed]

@Bruce Miller awesome. I'm putting that in my vw beetle.

[@jlo13800]

@@akbarshoed Are you running your beetle as a 2 stroke, they run oil injectiuon i though, not sure

[@MitzvosGolem1]

Look up a Napier Deltec triangle diesel .