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Ford Mustang Beyond The Basics
Vintage Mustang Tech Advice From Bob Aliberto
I have been collecting parts to build a 289 Hi-Po clone for a '66 hardtop. I've pulled a 289 from another car, and it has the wide Hi-Po harmonic balancer which was installed during its last rebuild. I have purchased Boss 302 rods and had them rebuilt with ARP Wave-Lock bolts. I also purchased a Competition Cams' solid roller cam and valvetrain, along with a Cloyes dual-roller timing chain. My question is, do I need to use the slide-on, stamped-steel crankshaft counterweight, or is the wide Hi-Po harmonic balancer enough to make up for the additional rod weight? If not, where can I purchase a dual-roller timing chain set with the integral crankshaft counterweight?
Via the Internet
The steel crankshaft counterweight was a clever way for Ford to balance the 289 Hi-Po engines with their heavier rod bolts. Simply adding the counterweight to an otherwise stock balanced crankshaft allowed the same crankshaft to be used in all 289s.
The counterweight can be eliminated if the assembly is balanced without it. Since you are changing connecting rods, you will need to have your parts balanced. Do so without the counterweight and the dual-roller timing chain can be used.
Matching Numbers 1967
I'm restoring a '67 hardtop, 7R01C112455. It is a local car and I'm the third owner. The second owner insists that the drivetrain is original, but I have some questions about the casting numbers: engine, C5AE-6015E-6C3; intake manifold, C60E-9425A-6C4; exhaust manifold, C60E-9451-6HS; and transmission, C6DP-7006-A. If my decoding is correct, the engine is for a '65 Galaxie, the transmission for a '66 Falcon, and the manifolds for a '66 Fairlane. Was it normal for the factory to borrow parts from other models, or has my driveline been replaced? Is my car considered "matching numbers"?
You are more aware of Ford's casting codes than most Mustang owners, in that Ford used the letter "A" for Galaxies, "D" for Falcon, and "O" for Fairlane. Codes were applied to parts to indicate the carline they were initially designed for, and even if they were used in other models, the code stayed the same as the original carline.
It's difficult to call an early Mustang "matching numbers" because Ford did not stamp the VIN into individual components (with a few exceptions, like the 289 High-Performance engine). For Mustangs without stamped VINs, people generally use the date codes on the parts to make sure they were manufactured around the proper build date for the car. Purchase a decoder guide from your favorite parts vendor to get a handle on your Mustang's date codes. Most parts should be within months, sometimes weeks, of your car's build date.
I own a '67 Mustang GTA fastback, powered by the 390 big-block, that's an original California car. A complete restoration was completed several years ago. The car runs great but I have an ongoing issue that I cannot resolve. When I try to restart the car after driving, the engine does not turn over right away. The starter lags and drags and then kicks in slowly. I suspect this is due to the starter heating up after the car has been driven, but I'm not sure. How can I cure the problem?
Newbury Park, CA
Any engine tends to crank harder when hot due to the fact that electrical resistance in a circuit increases with heat. If a starting circuit has a small issue, it typically shows up only after a hot soak. This is especially common with big-block Mustangs and is usually attributed to a bad connection or an internally corroded solenoid.
The correct procedure would be to conduct a voltage drop test at each connection while the engine is being cranked. Start with the battery post, continue to both sides of the solenoid, and end at the starter. To do this test, connect a voltmeter to each end of a cable or connection. With the ignition system disabled so the engine cannot start, crank the engine and measure the voltage drop across the connection or through the cable. The voltage drop should be less than 0.2 volts
The higher the voltage reading, the higher the resistance. I've discovered that older solenoids can be corroded internally even though their outward appearance is fine. The voltage drop is considerable in a corroded solenoid.
A quick backyard test often works. Simply touch each connection while cranking to see if any get hot. Be careful because a bad connection can get hot enough to burn. I've often used this method to find a loose cable connection on the starter itself.
Send your '65-'73 Mustang questions to: Beyond the Basics, c/o Bob Aliberto, P.O. Box 205, Salt Point, NY 12578. Send email to firstname.lastname@example.org.