Backward Is Backward, No Matter
What Direction You're Going
Q.In a recent car feature, somebody was worried about Ackerman being all wrong because the spindles on an early Ford front axle had been swapped to put the tie rod in front of the axle. Here's a thought: If the spindles had been left in the original position, would the Ackerman be wrong when the car backed up? I don't think so.Jan L. GilesLandscape ArchitectVia the Internet
A.Think of it this way, Jan, in your line of work, a shovel is a shovel, but if you tried to use it upside down, it wouldn't work very well.
Ackerman doesn't have anything to do with the direction the car is traveling; it has to do with the geometry of the steering linkage. Ackerman is necessary because when a car goes around a corner, the inside tire has to turn sharper than the outside tire, so the tires actually toe-out on turns. Imagine that you were looking down on a car as it traveled in a circle. The tires on the outside of the car would travel in a larger-diameter circle than those on the inside. That means the inside front tire has to turn sharper than the one on the outside so the tires track properly and neither will be dragged along as the car turns.
In most cases, early Fords as an example, Ackerman is established by the positioning of the steering arms on the spindles. If you drew lines from the center of each king pin through the pivot points on the steering arms, those lines would converge at the center of the rear axle (the amount of Ackerman necessary is also a function of the car's wheelbase).
If the spindles are reversed, Ackerman is now bassackward and the wheels will toe-in on turns. As a result, the outside tire will try to turn in a tighter circle than the inside tire; obviously that's not going to work well and the tires are going to scuff as they turn.
Take a look at the diagram above, courtesy of Pete & Jake's-it may help.
Passing Gas
Q.I could use some advice here. We are stuck on a problem and do not see an easy solution in sight, but I suspect this has all been worked out before by somebody else, some time ago. Here goes: I am constructing a 1931 Ford coupe with a nostalgia theme. The car will be a multipurpose car-drive, have fun, cruises, have fun, and occasional car show, have fun, and drag racing. Did I mention have fun?
Anyway, the car is powered by a tricked-out 1949 Mercury Flathead V-8, coupled to a Borg Warner five-speed, and a vintage Halibrand quick-change rearend. The car is fully fendered, unchopped top, with a late 1950s or early 1960s-era theme.
We have installed Tanks Inc. saddle tanks with the crossover switch, and have elected to use an electric fuel pump. The pumped fuel will actually go through the mechanical fuel pump housing then onto a 1953 Oldsmobile 4-bbl carb. All of this system is pretty straightforward, and seems to be a no-problem situation up to this point. Things got a bit complicated when I added a vintage Eelco 2.5-gallon racing fuel tank onto the front spreader bar, and I want it to be functional for drag racing.