The Toyota R family was a series of straight-4

Straight-4

The inline-four engine or straight-four engine is an internal combustion engine with all four cylinders mounted in a straight line, or plane along the crankcase. The single bank of cylinders may be oriented in either a vertical or an inclined plane with all the pistons driving a common crankshaft....

 gasoline

Gasoline

Gasoline , or petrol , is a toxic, translucent, petroleum-derived liquid that is primarily used as a fuel in internal combustion engines. It consists mostly of organic compounds obtained by the fractional distillation of petroleum, enhanced with a variety of additives. Some gasolines also contain...

 engines. Designed for longitudinal

Longitudinal engine

In automotive engineering, a longitudinal engine is an internal combustion engine in which the crankshaft is oriented along the long axis of the vehicle, front to back....

 use in such vehicles as the Celica

Toyota Celica

The Toyota Celica name has been applied to a series of coupes made by the Japanese company Toyota. The name is ultimately derived from the Latin word coelica meaning "heavenly" or "celestial"....

 and Hilux

Toyota Hilux

The Toyota Hilux is a series of compact pickup trucks produced and marketed by the Toyota Motor Corporation. Most countries used the Hilux name for the entire life of the series but in North America, the Hilux name was retired in 1976 in favor of Truck, Pickup Truck, or Compact Truck...

 and in production from 1953 through 1995, use faded out as many of Toyota's mainstream models moved to front-wheel drive. OHC versions featured a chain-driven camshaft

Camshaft

A camshaft is a shaft to which a cam is fastened or of which a cam forms an integral part.-History:An early cam was built into Hellenistic water-driven automata from the 3rd century BC. The camshaft was later described in Iraq by Al-Jazari in 1206. He employed it as part of his automata,...

, mitigating the danger of internal damage from interference as in belt-driven engines.
The 1.5 L (1453 cc) R family was produced from 1953 through 1964.

Bore was 77 mm (3.03 in) and stroke was 78 mm (3.07 in).