Michael Haynes Asks…
How can I make OE styled wheels fit Granada disc brakes on a 1966 Mustang?
Q: I changed my 1966 Mustang’s six-cylinder–style, four-lug front drum brakes and suspension to five-lug disc brakes off a 1974 Granada. I also bought 1966 styled rims. They are hitting the calipers. Do you know if I buy repro styled rims, will they fit the Granada front end, or if not, what I need to do?
A: For the benefit of our readers, the actual models so-called “Granada” brakes came on were the 1974–1977 Maverick/Comet and 1975–1980 Granada/Monarch. This once was a very popular swap for early Mustangs and Falcons, as well as other classic-era Ford muscle cars, but wrecking-yard parts are getting scarce—particularly the front steering knuckles (spindles), for which no parts-store replacement is offered. However, Classic Services Restoration Parts now has complete Granada conversion kits for various early Fords that come with all-new parts. The company has tooled its own spindles, even ones with corrected geometry to make the very early 1963–1965 Falcon/Comet and 1965–1966 Mustangs easier to align.
If you are going the wrecking yard route, grab at a minimum the front steering knuckles and everything outboard of the knuckles, including the dust shields, caliper brackets, calipers, brake rotors, brake hoses, wheel seals, bearing parts, dust shields, retainers, caliper keys, caliper tension springs, and pads. It’s wise to get the dual master cylinder from the donor car as well. The knuckle package bolts directly to early Mustang/Falcon ball joints. Similar-vintage Lincoln Versailles parts can also be adapted, except the Versailles steering knuckles have larger-diameter lower ball joints and won’t bolt directly to the Mustang/Falcon lower control arms without adapters (available from Mustang Steve). One neat thing about the Versailles is that they also came with rear disc brakes on their 9-inch Ford rearends—junkyard four-wheel disc brake swap, anyone?
Through all the different model years and options, the outer tie-rod ends’ taper and thread sizes vary, so the outer tie-rods must come from the donor car. Usually, ’66-and earlier V8 cars and all later models can use the original adjusting sleeve to mate the late outer with the original inner tie-rod ends. Early six-cylinder cars must install the complete V8 Mustang steering linkage from the model year in question.
In those rare cases where the inner and outer threads are not the same, sleeve adapters can be fabricated from solid stock, drilling and tapping dissimilar female threads as needed on each end.
On some cars, to achieve correct toe-in using original Ford Granada-style spindles, it may be necessary to shorten the inner and outer tie-rod-end threads that go into the adjusting sleeves as well as the adjusting sleeves themselves.
Now, as to your fitment/interference question, first things first: I’m not sure how you know that you have wheel-to-caliper clearance issues, as the original Mustang styled steel wheels shouldn’t even fit over the Granada rotor hubs, so in theory, you can’t get them installed all the way to see if they hit the calipers. The id of the hole in the center of the original early factory wheel is smaller than the od of the Granada rotor’s hub (snout). The solution is to have a machine-shop turn the rotor hub down in a lathe so it’s about 0.010-inch smaller than the center hole in the wheel. The original drum-brake bearing’s od can be used for a baseline measurement.
Once you get the old 14x5- or 14x6-inch styled wheel to fit over the rotor hub, it may or may not hit the caliper. Kevin, the tech advisor at Mustangs Unlimited, “brakes” it down like this:
If the wheels have only slight interference, the calipers can usually be lightly ground for clearance. To see how much of a shave the caliper needs, place several layers of masking tape on the offending caliper. Install the wheel and spin it. The rubbed-off area will indicate where to grind the caliper.
Another alternative is ¼-inch spacers to move the rim outboard. This solution could require correspondingly longer wheel studs to provide proper stud-nut thread engagement depth.
When all is said and done, you really need to ask yourself why you want to run old, narrow, 14-inch wheels on anything but a pure restoration of a rare, numbers-matching car. The availability of modern, 14-inch tires is decreasing. Why not consider some of the later Magnum 500–style wheels? As we move into the last several decades, this style of wheel continues to be offered, but in a variety of increasing widths and heights plus different backspacings that accommodate a variety of modern tires. Just a thought.
More information on Granada disc conversions, adapter parts, general advice, and different wheel fitments can be found in the contacts list at the end of the article.
Suspension Technology and Design Sources
Q: I have been a hot rodder/fabricator (and HOT ROD reader!) for quite some time. I’ve built racing cars, done engine conversions, and built and modified many of my own chassis and suspension components. Now I’d like to take it to the next level. Is there a good, modern book or computer program where I can learn theoretically ideal suspension geometry that I can use to design and build an entire suspension system? I’m looking to build a Pro Touring suspension that would see some track time. I realize there have been billions of dollars spent to design better systems that I can buy off the shelf for good value, but this is something that I have always wanted to do. And, yes, I have a large fabrication shop with some machining capabilities.
Mike Ball Via email
A: No doubt suspension books and software are a good starting point, but don’t discount the human element and that pesky distraction otherwise known as “the real world.” As Global West Suspension’s Doug Norrdin puts it, “There is no magic bullet. You can start with the theory and the math, but there is no substitute for real-world testing. If there was an ideal suspension geometry, all suspensions would be the same. Just like engines, there are many different combos that can accomplish a similar result. You can’t expect to just design off a computer and have everything work properly. There’s just too many different dynamics at play. And there’s no substitute for experience.” In other words, the book or computer can help narrow down the possibilities, but be prepared for plenty of real-world testing of the basic “paper” concept.
Remember, too, that tires are as important as the suspension. They must compliment each other. Finally, there’s the driver. Driving styles and techniques vary, so different drivers often prefer different setups, even on the same car. You’ll find that real race cars are fine tuned for both the specific track as well as the driver.
To some extent, all suspensions represent a compromise. In the case of a road car, lots of compromises! A road car must accommodate less-than-perfect public roads, dips, off-camber turns, varying loads (passengers or trunk cargo), getting in and out of driveways, and the comfort and convenience desired. Production cars are designed for average drivers and average conditions. Among domestic cars, one of the best all-around suspensions that can serve as a basis for serious performance work is from the modern Corvette. If you don’t believe that, look at how many aftermarket front-clip and chassis makers use the late Corvette suspension in their kits.
No matter what the starting point, on a suspension designed for a road car, the more it’s modified, and the closer you move to a pure race car, the less happy the car will be on the street. Air suspensions or even fully active electronic suspensions may overcome these limitations, but with a weight or cost penalty. There is no free lunch, but if you have a basic understanding of suspension parameters, just about anything can be fixed or optimized. Get out your wallet!
All that said, you have to begin somewhere—so, yes, there are a number of good suspension books. I still like the classics from Carroll Smith and Paul Van Valkenburgh. Smith’s are written in plain English and easily understandable, practical terms. William F. Milliken wrote the textbook; it’s more than 1,000 pages, but the currently available version includes practical problem-solving plus a CD with exercises and a Race Car Vehicle Dynamics suite. For modern tire theory, see Paul Haney’s book. These books tend to be fairly pricey, either because they’re out of print and only limited supplies are available new, or because they are voluminous textbooks. But if you’re up for it, here’s my recommended reading list (pricing is new via Amazon.com as of May 2013).
A reasonably priced computer-software suspension analysis and design program is Performance Trends’ Suspension Analyzer, currently at Version 2.4. Prices range from $250–$420, depending on the level of sophistication and features you want. The hardest-core 3D modeling, simulation, CAD programs typically start around $1,000 and go up from there.
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