Cadillac LM7 Specs: 3.78 x 3.622 in, 285 hp

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Cadillac LM7 specs: 325 ci (5.3L) 8-cylinder, 3.78 x 3.622 in (96 x 92 mm) bore and stroke, 9.5:1 compression. Rated 285 hp, 2002–2005.

The Cadillac 325ci (LM7) is close to square: 3.7799" bore against 3.622" stroke, within 4.4%, which splits the difference between a high-revving layout and a torque layout. The 3.622" stroke puts mean piston speed at 4,000 ft/min around 6,650 RPM, which is where a production bottom end is generally considered at its limit. A rod ratio of 1.684 is in the range most production engines fall in. Each of the 8 cylinders displaces 40.6 ci (666 cc).

9.5:1 on aluminum heads is in the range that usually runs on pump premium; aluminum sheds heat faster than iron, which makes the same number a little more forgiving.

4 factory variants share these dimensions, rated at 285 hp across 2002–2005.

Dimensions

Displacement325 ci / 5.3 L
Bore3.7799"
Stroke3.622"
Cylinders8
ConfigurationV8
Compression ratio9.5:1
Rod length6.098"
Rod ratio1.684
Bore/stroke ratio1.044
Deck height9.24"

Construction

Block materialcast iron
Head materialaluminum
ValvetrainOHV
Fuel typegas
Advertised HP285 hp
Years2002–2005

Factory clearances

Piston-to-wall clearance (factory service manual spec, 2003 GM truck LM7 production (negative = interference; coated skirt). Service limit 0.0028 with coating worn off)-0.0014–0.0006"
Piston-to-wall clearance (factory service manual spec, 2003 GM truck L59 production (negative = interference; coated skirt). Service limit 0.0028 with coating worn off)-0.0014–0.0006"
Ring end gap (factory service manual spec, 2003 GM truck LM7, production (service: 0.009-0.0196 / 0.0173-0.030 / 0.007-0.032))top 0.009–0.017", second 0.017–0.027", oil 0.007–0.029"
Ring end gap (factory service manual spec, 2003 GM truck L59, production (service: 0.009-0.0196 / 0.0173-0.030 / 0.007-0.032))top 0.009–0.017", second 0.017–0.027", oil 0.007–0.029"

What these numbers mean

Bore/stroke character1.044 — square — bore and stroke are within 5%, a balanced compromise
Mean piston speed at 6,000 RPM3,622 ft/min — in the range typical of performance street engines
Rod ratio1.684 — moderate — the range most production V8s fall in
Displacement per cylinder40.6 ci
Static compression9.5:1 — in the range that usually runs on pump premium

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Variants sharing these dimensions (4)

These records share identical bore, stroke, displacement and compression. They differ by model year and factory power rating.

YearAdvertised HPCode
2002285 hpLM7
2003285 hpLM7
2004—LM7
2005—LM7

What cars have the LM7?

11 factory vehicles, 1999–2007. Each year opens that model's engine table.

Similar engines

← All Cadillac 325ci engines