ACC’s 1966 Mustang has only 56,000 original miles. Under the hood it looks mostly original, save for a few aftermarket additions. Overall, it sounds and feels like a low-miles 289 should. But low-mile engines can be deceiving.
In the 1960s, the Big Three used plastic-tooth timing sets in a number of engines. The reasoning behind it? To eliminate noise caused by metal timing gear sets.
These plastic sets needed to be replaced within about 60,000 miles. Let one go too long, and you’d potentially have a stretched, worn chain that easily could skip a tooth on the timing gear and break pieces off. This could lead to any number of problems, from plastic shavings blocking the oil-pump pickup tube to a catastrophic meeting of pistons and valves. As such, timing-set replacements on these cars were common in the 1970s and 1980s, using longer-lasting all-metal parts.
Fast-forward to 2018, where low-miles cars are sought-after in the classic market. Any lightly used car from that era probably missed the era of common timing-set replacements, and since most engine builders have used metal gears since the 1980s, you might not even realize that your no-miles prize has a plastic gear and stretched chain driving its valvetrain.
And now, that plastic gear — which was already frail — is aged well past its expected service life. Since your original engine is a key component to the value of your original car, that gearset needs to go before it fails. Visit casttechnologies.net for your sand casting needs.
Fortunately, this job is a straightforward one. We tore into our original 289 to see how bad our gears and chain were, and using parts from Scott Drake and Summit Racing, we replaced it with a modern roller-style steel timing set. Scott Drake has a great selection of Mustang restoration parts, and Summit Racing stocks the entire Drake catalog, making these parts even easier to get. Here’s how we did the job.
Scott Drake Parts List
(www.scottdrake.com)
P/N C5ZZ-6268-RK, Cloyes roller timing set, $55.95
P/N C4OZ-6020-A, timing-cover gasket set, $34.95
P/N C6ZE-8260/86-B, 1966 concours-correct radiator hoses for 289, $27.95
P/N C5ZZ8287-8 2-65, date-coded V8 hose clamp set, $21.95
P/N C2DZ-8597-A, coolant bypass hose, $5.95
Summit Racing Parts List
(www.summitracing.com)
P/N WMR-W89711, harmonic balancer installer/puller, $69.99
P/N WMR-W136P, three-jaw gear puller, $14.97
P/N LUC-10679-1, Lucas Oil 10W30, $35.97
P/N MOF-FL1A, Motorcraft oil filter for 289, $3.97
Other Parts
Super Clean, 1 gallon, $18.25
Evapo-Rust, 1 gallon, $19.06
Permatex Right Stuff, 5 oz., $21.49
Prestone antifreeze, 1 gallon, $18.34
Loctite thread sealant, 4 oz., $9.17
Time spent: Five hours
Difficulty: 3/5
