Continental ADF-268

[Piper106]

Anyone have information on the Continental AO-268 engine. Bore & stroke??
The designation makes me think it is 268 cubic inches (about 4.3L) displacement.
It was used in the early 1950s / Cold War era M-76 Otter amphibious vehicle.
The one picture I have seen it is a air cooled flat 4 cylinder, like a A65 or C85 aircraft/helicopter engine.



Thanks for your help.

Piper106

[Aaron Brooks Wolters]

I'm not finding a single thing on line. Will keep looking though.

[Shortround6]

It is 268-269i cu in displacement, I can't find details but it should be a 4 cylinder version of the 402 cubic inch flat six used the M-56 Scorpion.

[Piper106]

Was able to answer my own question.

Yesterday I picked up a copy of "Continental - Its Motors and Its People" by William Wagner ISBN 0-8168-4506-9.

While not extremely 'techie' on page 126 it shows the AO-268 as having for 4.625" bore x 4.00" stroke cylinders. It was one of a family of air cooled 'flat' (opposed cylinder) engines for post WW2 military vehicles, there also being a 6 cylinder (AO-402) and a (proposed but never built in quantity) 8 cylinder version (AO-536) using the same size cylinders.

Piper106