See other engines in this family
GMC LLR specs: 223.9 ci (3.7L) 5-cylinder, 3.76 x 4.055 in (95.5 x 103 mm) bore and stroke, 10:1 compression. Rated 242 hp. DOHC. Rod ratio and piston speed.
The GMC Vortec 3700 (3.7L I5) (LLR) is undersquare — the 4.0551" stroke exceeds the 3.7598" bore by 7.3% — a layout that trades peak RPM for leverage and torque low in the range. The 4.0551" stroke puts mean piston speed at 4,000 ft/min around 5,900 RPM, which is where a production bottom end is generally considered at its limit. Each of the 5 cylinders displaces 44.8 ci (734 cc).
10:1 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.
Factory fitments include the GMC Canyon, Chevrolet Colorado, Hummer H3 and 1 other.
| Displacement | 223.9 ci / 3.7 L |
|---|---|
| Bore | 3.7598" |
| Stroke | 4.0551" |
| Cylinders | 5 |
| Compression ratio | 10:1 |
| Bore/stroke ratio | 0.927 |
| Block material | aluminum |
|---|---|
| Head material | aluminum |
| Valvetrain | DOHC |
| Fuel type | gas |
| Advertised HP | 242 hp |
| Bore/stroke character | 0.927 — undersquare — stroke exceeds bore, which favours low-end torque |
|---|---|
| Mean piston speed at 6,000 RPM | 4,055 ft/min — in the range typical of performance street engines |
| Displacement per cylinder | 44.8 ci |
| Static compression | 10:1 — in the range that usually runs on pump premium |
Each link opens the calculator with this engine's specs already filled in.