roadster unibody hacks

this page under construction.

alas, my poor 1963 Rambler American hardtop. though a joy to drive, it was fairly rough when i got it. likely it will be the last unreconstituted "old car" i kept on the road. i got it as a hulk, got it running, rebuilt the drive train, fixed up the rest, and drove it. it ran great, but rattled, squeaked, leaked, and generally the chassis drove me crazy. in 2012 i drove it on the Bonneville Salt Flats -- big mistake, don't do that with any car you care about, the salt eats everything and rapidly and you cannot rinse it all out -- then some jerk shot the windows out when it was parked on the street in december 2013. by that time this roadster was under way, and i'd already decided the '63 would be the driveline donor, so i took it off the road at that time.

the 1961 rambler american i got from the other joe. it drove here, barely, but needed a new everything. once parked, it was clearly not going to drive again without massive intervention. at 53 years old every single thing was worn past usefulness. i oiled down the cylinders and decommissioned it.

all production cars are ephemeral products, function and construction devoted to profitable sales. the inherent and obvious transportation angle long since resolved (from a marketing point of view). cars are designed to last long enough (just) to not harm the manufacturers' reputation. all of this is visible to those of us who take cars apart. my ramblers were reasonably well made (at least through the late 1960's), but this nash-designed car turned out to be exceptionally well made. shockingly so. as wonderful as this was to stumble on, it is part of why the Nash Motor Company wasn't doing well -- expensive to make, old (pre-war) technology, poor sales. none of that is of concern to me, now.

after the revelation of the Golden Rule the design came together quickly. the major design hack was to turn a four passenger sedan into a two seat roadster; that meant repurposing the rear seat space in a way that made sense, design-wise. know- or like-it-or-not, most westerners are ersatz car-design experts; car fan or not, you can easily see ugly (imagine: Pontiac Aztec). this sets a high standard.

while i was cogitating on how to pull off this task, i decided to chop out and replace the firewall, as part of the "remove ugly" phase.

the a-pillar is the vertical post that holds up the roof in front. it was a major detail in the roadster conversion. it was one of the few areas of the unibody that Nash made [internally] ugly, a side effect of continuous styling revision; "dressing up the old girl" a later AMC designer would call this process. since i decided to forgo the usual roll bar i added a vertical/diagonal brace to the a-pillar, in a way that mimiced the original vent window, visually integrating the brace into the design.

the rear deck lid was the single most significant restyling element in the car. again, the Golden Rule discovery dominated here; it singularly solved the design problem. the lid is the hood of the car, shortened. a subframe was built to at once stiffen the chassis and provide a mount for the lid, typing the b-pillars together, creating a stiff and light box around the passenger compartment. (side-impact safety was not a factor in cars of this era.)

it is here that i became (somewhat) enlightened to the abilities of cold-rolled sheet steel. sheet steel is plastic, the verb. the lid required construction of metal structure that conformed to a specific curve -- the Golden Rule -- in three planes. i made it so with a cheap ball peen hammer and a piece of plywood. (OK, and a plasma cutter and MIG welder.) this is "ten foot" body work -- by choice and by limitation. but it is functional. it is stiff and light.

with the lid done, defining the back half of the cockpit, it was time to rough out the rest of it. in the original car, the instrument panel occupied the space below the windshield, and hid all the ugliness of the clutch, brake and parking brake pedals, electrics, heater, wipers, instruments, etc. since all of that was scheduled for removal everything needed to be revisited.

the placement the steering wheel was a given, at the end of the steering shaft out of the old steering box. everything else was an open question. it was rapidly obvious that the pedals and attendant infrastructure would go in the floor, where this stuff would be for the first 30 years of automobiling, and where most hot rods have them. i further decided to make my own. this took place, incrementally, from this point (december 2013) through completion (october 2014).

the peculiar tripod that holds the steering shaft up is peculiar for a reason -- the tripod provides the required stiffness, but the placement of tubing keeps the vertical space very short -- the instrument panel attaches to the cowl just below the glass. the support tripod cannot be further down the firewall because right at the base of the steering wheel is the head-end bearing and support. the adjustable sleeve holds the stock Nash bearing assembly. not obvious is that at the firewall is a nylon bushing that locates the steering shaft when you lean on the steering wheel; given the combination of shaft lengths the "leverage" at the nylon bushing is adequate to keep everything very stiff.

though i meant this website to be an overview, by necessity this section, the pedals, is am overwhelmingly important functional area. get this stuff wrong and the car is unusable. this mundane-seeming stuff is the very core of the human interface; done right, they become invisible, unnoticed. get it wrong, and it could be literally fatal or at least, uncomfortable and/or inconvenient. i spent a lot of time getting this right. two iterations were made, the first was scrapped. unsurprisingly, what i ended up with looks a lot like commercially available race car stuff. however, no one makes anything to fit Ramblers. and i didn't want a race car, or to look like one.

the largest most difficult single task in this project was cleaning, especially the unibody. talk about understatement -- cleaning just the bottom of the chassis took three full weeks of eight-hour days. scraping, chipping, grinding, sanding. easily 100 pounds of undercoating, sound-proofing, rust and dirt were removed. the sound-proofing/undercoat seemed to consist of asphalt and clay; cheap and heavy. the purpose of said material is evident when you whack this car with your hand; it now rings like a drum. light weight has it's own penalties.

the entire chassis was scraped to bare metal or good primer and painted with Eastwood Chassis Black. this is the source of the "shiny side down" tag line, and befits the industrial aesthetic. utterly unsuspected from above, the working parts of this car look like aereospace gear down below. this is no accident. few will ever see it, even fewer will bother to look. this is not of concern to me,

the front quarters of the car contain the engine and front suspension. rather mundane and uninteresting in spite of the critical function, nonetheless a lot of time gets spent here, building and maintaining.

roadsters do not have doors, passenger cars do. it's the roof of a car that provides box-like stiffness, necessary for safetly and reliable operation; some "chop jobs" ignore this and the car sags in the middle. i added triangulated DOM tubing sub-framing between the a- and b-pillars, which ties in with the lid support subframe and the skinned firewall to make for (what i hope is) a very still box containing the passengers. it's certainly safer than factory, where one layer of 18 gauge sheet steel, the windup window, and a cardboard panel was all that was between you and the truck about to T-bone you.

at this point in the project i was confident of completion. everything to this point was contingent on actually executing the fundamental ideas behind the roadster: firewall, a-pillar, doors, sedan-to-roadster in-fill. those are the big chunks. now it was time to move on to important but functionally-secondary aesthetic changes. here, reshaping the wheel cutouts.

automobile styling from the 19th century through the 1970's was dominated by the "classic" -- the flowing fender, round in front, tapering to a point behind, a teardrop shape. explicit through the 1930's and 1940's, it remained a style element post-war, clung on through the slab-side movement of the 1960's, and only with the (welcome) assault of asian imports, did the "classic" teardrop line disappear. GOOD RIDDANCE.

in slab-sided nash ramblers, the classic line took the form of teardrop shaped wheel openings. that's what really makes a post-war car look fundamentally old! and at a minimum, it was a functionless decoration. there is a difference, sometimes blatant, sometimes subtle, between decoration of an otherwise necessary shape, that is either acceptable or outright desireable. then there's pointless decoration; nash wasn't so bad about this, but the wheel cutouts screamed design conservatism at it's worst.

the valance is the thing that you scrape on those concrete stops in parking lots. it's a dent collector. in cars of this vintage they mainly hide behind the bumpers -- which were clearly deleted by me, here. i ended up making this part completely. only portions of the curve at each corner are "original".

less obvious, but critical to the redesign, is that the front lower edge of each front fender is pulled in nearly four inches. a major "feature" ("wart") of the post-war Nash Airflyte design that rambler inherited is this feature where the tall skinny wheels are tucked well inside the fenders, necessary for the "streamline" but later derided as the "inverted bathtub" look. talk about old-fashioned... by pulling the fender leading edges in, exposing the tiniest corner of the tires, the upside-down bathtub looks is hopefully dispelled. the same was done to the rear quarters, to a lesser extent. it's the front "bathtub" that dominates.

i completely messed up the placement of the rear quarter wheel cutouts -- i could now claim that it was all intentional, but it wasn't. what began as serious dismay turned into a feature when i learned to see it properly... i did the rears first as stated, but without the axle, wheel and tire in place, going by measurement. the wheel openings are almost perfectly circle with the tiniest bit of increased radius towards the back -- yes, the classic! reduced to microscopic proportion... i made two mistakes: too large a diameter, and placed the new cutout off-center (it was meant to be perfectly concentric with the axle). i discovered this when i installed the axle months later. it took me a couple days to get over the rather severe disappointment -- until i realized that by placing the too-large radius up and back, it created a "nautilus" effect, invoking a bit of motion. so i duplicated the error on the front and lo! perfection.