Mercury 256ci Specs: 3.625 x 3.10 in

Mercury 256ci specs: 3.625 x 3.10 in (92.1 x 78.7 mm) bore and stroke. Displacement, compression and factory ratings, plus rod ratio.

At a glance

Displacement	256 ci
Cylinders	8
Bore	3.625"
Stroke	3.100"
Compression	7.5:1
Advertised power	161 hp
Years	1954

This engine

Engine	Displacement	Bore × Stroke	CR	HP
Mercury 256ci (1954)	256 ci	3.625" × 3.1"	7.5:1	161

Factory cars with a Mercury 256ci

• Mercury Monterey: 1954, 161 hp

What varies across the family

This family is represented by a single engine in the database: 256 ci, 8 cylinders, a 3.625" × 3.1" bore and stroke.

All are oversquare — bore larger than stroke, which favours revs over low-end torque.

Each engine page carries rod ratio, mean piston speed, bore/stroke character and cylinder head specs where published, and links into the calculators with its dimensions already filled in.

← All Mercury engines