Tech Focus: Ford Pinto Engine Rebuild

Part one: In the first of a two-part series, we follow the stripdown of a rusty-looking two-litre Ford Pinto engine.

In the first of a two-part series, we follow the experts as they strip down a very sad and rusty Pinto 2.0-litre engine.

When the fastback-shaped Ford Pinto was launched in the USA in 1971 powered by a cast iron single- overheadcam four- cylinder engine with flat top pistons and a five main bearing crank underneath its bonnet, little did anyone expect that this engine would become more popular than the car, or that it would adopt its name. It wasn’t until 1973 that the UK had the opportunity to appreciate this engine in the MkIII Cortina 1600GT. With a displacement of 1592cc, it produced 88bhp at 5700rpm, whereas the larger and now more readily available 1993cc version had an extra 10bhp at 5500rpm.

With many engines having been rebuilt or modified over the years and few remaining in original condition, it’s often difficult to identify them, although markings such as 2.0 or 1.6 on the side of the engine block (and even on one of the webs of the crankshaft) should help. There may also be a 0 or 6 mark on the cylinder head to identify a 2.0 or 1.6 unit. Three holes in a triangular formation on the inlet side of the head help to identify a two-litre cylinder head. Finally, if there’s a 2.0 LC mark on the top of the pistons, this signifies a two-litre low- compression engine from a Ford Transit (although highcompression pistons can be fitted instead).

There are several common problems associated with the Pinto engine. One of the main weak spots concerns oil. Early engines suffered from camshaft wear because the engine was tilted, so the oil supply to the camshaft via a spray bar was weak. After modifying the spray bar this was resolved, but the bar can still become blocked and potentially starve the cam. The other oil-related weak spot concerns the small hexagonal drive for the oil pump, which can wear or break.

Poor maintenance, especially infrequent oil changes, can result in crankshaft wear and low oil pressure. Similarly, if the coolant level drops and the engine runs hot or overheats, the cylinder head can crack – unleaded petrol can also cause cracks between the valve seats, and a weak fuel mixture can burn out valves.

We’re beginning this two-part Pinto engine rebuild series with the stripdown of a cylinder head and engine block at engine specialist W. Drake. The cylinder head can be removed from the engine block by undoing a series of ten stretch bolts, which will have either a 12mm-splined or Torx T55 head. They can be accessed after the removal of the camshaft cover, which is fitted with ten 10mm bolts (remember the order of fitment as they are different lengths). In the next issue of Classics, we’ll be showing how to check over the engine’s internal components, reveal what can be machined and show how to rebuild a 2.1-litre motor.