Caterpillar 1145

The Caterpillar 1145 is a naturally aspirated, mechanically governed 90-degree V8 diesel truck engine displacing 522 cu in (8.6 L), rated V-175 at 175 hp (131 kW) at 3200 rpm with 352-353 lb-ft (477-479 Nm) of peak torque, the exact figure depending on model year. It is one of four displacement and output points in Caterpillar's 1100-series truck engine family alongside the 1140 (V-150, same 522 cu in block, 150 hp), the 1150 (V-200, 573 cu in), and the 1160 (V-225, 636 cu in); all four share the same 4.5 in bore head and block casting and differ mainly in stroke, rated rpm, and fuel calibration. Caterpillar built the 1145 as a bare engine for Ford's medium-duty truck lines - the F, B, C, and LN 6000 through 8000 series - during an exclusive supply arrangement running from January 1968 through 1974. Fuel is metered by plunger-and-barrel injection pumps mounted in the engine vee, one per cylinder, feeding injection nozzles through high-pressure lines; a mechanical governor and a separate timing-advance unit control speed and injection timing, and the 1140/1145 pair runs without a crankshaft vibration damper, unlike the 1150/1160. Caterpillar catalogs the 1145 as a bare engine listing carrying serial prefix 97B; it was never sold as a complete vehicle, so no factory chassis or operating-weight rating attaches to the engine number itself.

Within the 1145's run Caterpillar revised the torque rating once: 1968-1969 production is rated 352 lb-ft (477 Nm) at 1600 rpm, while 1970-1974 production shifted to 353 lb-ft (479 Nm) at 1700 rpm, with horsepower unchanged at 175 at 3200 rpm. The larger difference across the 1100 series came from block size rather than electronics or forced induction - buyers chose between the 1140, 1145, 1150, and 1160 purely on displacement and output, and none of the four ever received a turbocharger or emissions controls. Caterpillar phased out the whole 1100 series by the mid-1970s in favor of the larger-block 3208, which took over the same Ford medium-duty applications with more displacement and, later, turbocharged variants. In the used and parts market today, the 1145 mainly surfaces as a low-hour take-out core or rebuilt unit for owners of surviving Ford 6000/7000-series trucks and for Caterpillar collectors restoring period-correct machinery. Its simple mechanical fuel system, camshaft-driven injection pumps, and complete absence of electronics make it straightforward to keep running with basic tooling, but new-old-stock parts are increasingly scarce, so an intact core or a rebuildable block commands a real premium over the paperwork alone.

Below: full specifications, fluids & capacities, the factory service schedule, common service parts, verified fault codes, what owners discuss, attachment guidance, the complete assembly directory, and a serial-number reference. Complete parts lists with full OEM part numbers, exploded diagrams, quantities, and fitment data are available free in Heavy Parts AI.