When we last left the Ranchero, we’d finished up Arse-Freeze-a-Palooza “victorious” in class F against Top Gear USA. (By the way, how long do we think it’ll take them to get that episode on the air? Surely one of their legion of regular viewers will let us know). We’re all set on the fuel issues that held us back, so for February’s Sears Pointless we’re seeing what we can do to wring a few more ponies out of our 200ci straight six. After all, we spent most of our running time posting laps on par with the Corona and the Geo-on-520-treadwear-Primewell-tires for bottom-three lap times.
The to-do list for this past weekend:
- Replace crapped-out leaf spring shackle mounts with sliders (then trim fenders to accommodate lower stance)
- Swap in a 2-barrel carburetor (and adapter and build a linkage from scratch)
- Fix exhaust leaks (then just give up and install a header)
- Swap in Duraspark electronic ignition and higher-voltage coil (despite not having all the wiring to do so)
Click through to see how it went…
Trading Swinging for Sliding
Right after the race, I parked the car in the corner of my driveway, dropped all the crap in the garage and ignored it until 3 weeks ago. Finally doing a proper post-race debrief, I noticed came to learn the right-rear leaf spring shackle mount had snapped off. The leaf was just resting on the frame, bottoming out against the old bracket. The other side had flipped its shackle, so basically we had no rear suspension. I briefly considered rebuilding new, better shackle mounts or even swapping different leaves, but in the end the simplicity of sliders won out. A slider replicates the function of a shackle, allowing the leaf to get longer as it flattens out, but doesn’t have the tendency for side-to-side sway that a shackle does. Also, they’re just a flat piece of steel box section, so they’re easy to weld in place along the frame rails.
After cutting off the old bits, these lined up just fine, but the tight quarters made it hard to get particularly great welds on the sides. Additionally, these sliders are for 2.5″ wide leaves, but ours are 2″, so a stack of washers was employed to take up the slack.
Actually having a functional rear suspension means your tires will go even farther into the fender wells, so Jeff drew the short straw and ate sparks while cutting out the inner fender liners. That reminds me, we’ll have to take a coil or two out of the front end as well.
Next up: Breathing, in and out.
While dropping on a bigger carb is a bit of a hot-rod cliche, there’s no way we can’t gain a few ponies (particularly up high) from a freer flowing Autolite 2100 280ish-CFM carb. Even if it’s breathing through the 1.75″ single-barrel intake opening, it’ll still flow better than the original. Of course, that meant Jeff had to fabricate a new linkage from our push-crank pedal linkage to the 2100’s throttle arm. After a few “OMFGGASSPRAYINGEVERYWHERE!” moments, we had the thing idling down at 750 RPM and running good A/F ratios according to our wideband 02 sensor.
On the other side, we really tried not to throw this cheaty header on. Really. We had exhaust leaks at the gasket and a bolt in the stripped threads an oil air injection hole in the manifold. The gasket sealed back up OK, but JB Weld-ing the bolt failed to plug the leak. That hole was a threaded hole in a bigger threaded insert, a definite recipe for busted taps, late-appearing cracks or threads that still leaked. Instead we said “screw it” and swapped in a (surprisingly cheap) header. Of course, it required a bit of precision adjustment courtesy of two rounds of torch-and-hammer therapy. Following that, we’ll have to fab a whole second exhaust track, as it’s a 2X(3-into-1) configuration. Looks like I’ll have to pick up another $18 cherry bomb and make a second trip to the dumpster at the local exhaust shop.
And lastly: Spark
This one’s fairly straightforward: better spark timing and higher voltage make for better combustion. In 1977 Ford introduced the Duraspark II magnetic pickup ignition system across all its cars, finally obsoleting points. We’d picked up the Duraspark 2 distributor in a pile of parts at a yard sale, but had never bothered to get the control box, cap or plug wires that went with it. We grabbed all of the above from various parts stores for crazy-cheap (hooray for high volume through shared parts), and Ted (aka Dad) mounted everything up and made harness. With a hotter coil we’ll be able to open up those plug gaps and delude ourselves to thinking we’re making way more power.