Cadillac Ecotec Engine Specs

Bore, stroke, displacement and compression for all 2 Cadillac Ecotec engines, compared side by side. Plus rod ratio and head specs where published.

At a glance

Displacement	121.9–122 ci
Cylinders	4
Bore	3.268–3.386"
Stroke	3.386–3.634"
Compression	9.2–10.0:1
Advertised power	237–272 hp

Engines in this family

Engine	Displacement	Bore × Stroke	CR	HP
LTG	122 ci	3.3858" × 3.3858"	9.2:1	272
LSY	121.9 ci	3.2677" × 3.6339"	10:1	237

Factory cars with a Ecotec

• Pontiac LeMans: 1989, LT2, 95 hp; 1990, LT2, 96 hp
• Buick Regal: 2014, LTG, 259 hp; 2015, LTG, 259 hp; 2016, LTG, 259 hp; 2017, LTG, 259 hp; 2018, LTG, 250 hp; 2019, LTG, 250 hp; 2020, LTG, 250 hp
• Chevrolet Camaro: 2016, LTG, 275 hp; 2017, LTG, 275 hp; 2018, LTG, 275 hp; 2019, LTG, 275 hp; 2020, LTG, 275 hp; 2021, LTG, 275 hp; 2022, LTG, 275 hp; 2023, LTG, 275 hp

What varies across the family

Both bore and stroke vary across the family, so these are separate castings rather than variations on one block.

1 of 2 are undersquare — stroke larger than bore, favouring torque low in the range.

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.

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