The lifespan of this (or any other) engine will vary drastically; depending on the way it has been driven and maintained. If the oil and oil filter has not been changed regularly, and/or different brands of oil were often used when oil had to be added, and/or the ignition timing was not set properly, and/or the fuel filter was not replaced at recomended intervals, and/or the wrong type of spark plugs were used, and/or the coolant was not changed according to manufacturer's recommendations; the engine could wear out in 60,000 to 90,000 miles. But if the engine was allowed to overheat; due to the coolant not being kept at proper levels and not being checked at the radiator when the reservoir went dry, the engine could be severely damaged or even destroyed at any mileage.
But if the engine was serviced properly, at recommended intervals; and only one brand of oil has ever been used in that motor, and the coolant has been changed as recommended, and the engine has not been abused by the driver(s); it should be able to run 150,000 to 250,000 miles.
My experience has been that few vehicles end up lasting as long as they potentially could; because few owners bother to maintain their cars as well as they need to be maintained. The problem is compounded when shops install the wrong parts; make incorrect adjustments, mis-diagnose problems, or deliberately lie to the owners about the work that has been done.
Some engines have design problems, which limit their life expectancy; but such cases are relatively rare.