Plymouth Slant-6 Engine Specs

Bore, stroke, displacement and compression for all 13 Plymouth Slant-6 engines, compared side by side. Plus rod ratio and head specs where published.

At a glance

Displacement170–225 ci
Cylinders6
Bore3.402"
Stroke3.126–4.130"
Compression8.2–8.4:1
Advertised power90–145 hp
Years1960–1987

Engines in this family

EngineDisplacementBore × StrokeCRHP
LG225 ci3.4016" × 4.1299"8.4:1145
225 Slant 6225 ci3.4016" × 4.126"8.4:1145
C225 ci3.4016" × 4.1299"—110–145
Slant Six 1-bbl225 ci3.4016" × 4.1299"—145
225 Slant Six 1-bbl225 ci3.4016" × 4.1299"—100–145
Slant-6 (1960–1980)225 ci3.4016" × 4.1299"—90–145
1-bbl225 ci3.4016" × 4.1299"—95
Slant Six 225225 ci3.4016" × 4.1299"—95–110
RG198 ci3.4016" × 3.5591"8.4:1125
B198 ci3.4016" × 3.5591"—125
Slant-6 (1970–1974)198 ci3.4016" × 3.5591"—95–125
G170 ci3.4016" × 3.126"8.2:1101
Slant-6 (1960–1969)170 ci3.4016" × 3.126"—101–115

Factory cars with a Slant-6

What varies across the family

Every engine here shares a 3.4016" bore; displacement varies by stroke alone, which is the signature of a family built on one block with different cranks.

The family mixes oversquare and undersquare designs, so members behave quite differently despite sharing a name.

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 Plymouth engines