Our Daydreaming Auto Designer Reimagines A More Modern Version Of The Legendary GMC Motorhome That Died In 1978

Gmcmotorhome Top

In hindsight, the GMC Motorhome is an incredible, improbable thing. Campers and RVs and Motorhomes or whatever you want to call those drivable houses-on-wheels have always been the domain of smaller, lower-tech specialist companies as opposed to major automakers, which is why so many RVs are built like construction company office trailers bolted to a truck chassis. The GMC Motorhome was different, enjoying the full engineering might of GM to make something really special. Too bad it died in 1978. Well, in reality it died in 1978, but in the mind of The Bishop, our closeted auto designer currently toiling in another field, the GMC Motorhome was reborn in the 1980s! Let’s enter this glorious fever dream and delight at what could have been if it were all fortunate enough to live beyond the damp confines of The Bishop’s head.

Before that, though, let’s just go over one more time why the original GMC Motorhome was such a big deal. Other than perhaps Volkswagen with its Westfalia-camperified Type 2 Microbuses, no major automaker was selling its own, in-house-designed RVs or motorhomes, certainly not ones built on a purpose-built chassis. But that’s exactly what GM did.

The state of RV design in the early 1970s was crude, even the good ones like Winnebagos: corrugated metal, pink insulation, boxy, curve-less designs on heavy chassis. They were charming, but crude as hell.

Winnebago1

GM took a clean-sheet approach, and attempted to make something that was better than driving a giant shed, and at least attempted some degree of aerodynamics. The company took its tidy front-wheel drive V8 powertrain from the Oldsmobile Toronado and Cadillac Eldorado and plopped it down in a bespoke chassis with a nice low floor, no driveshaft, and plenty of room for fuel, fresh water, and disgusting water tanks, and then dropped on that an extruded aluminum frame covered with fiberglass and aluminum body panels.

Gmc1

The rear had twin axles with independent air suspension, and the result was something roomy and comfortable and not horrible to drive. Ads of the era emphasized this a lot:

Gmc Ads

 

When GM engineers really put their collective minds to something, they can do amazing things, even if they often screw them up later. The Motorhome was an example of this, with GM developing what was arguably the finest commercially-available vehicle that you could drive, sleep, and shit in.

Also, you may remember the GMC Motorhome played a role in the 1981 Bill Murray/Harold Ramis army-comedy Stripes as a fictional Urban Assault Vehicle:

Anyway, all of this is to say that the GMC Motorhome was a remarkable RV milestone, and yet it only lasted five years, from 1973 to 1978. The discontinuation of the Toronado and its V8 FWD drivetrain was a factor, as was the fuel crisis.

The story in our stupid reality ends there. But, now we dive into the gooey depths of the Bishop-brain, where we discover that, holy crap, GM resurrected the Motorhome project in the late 1980s, and had an all-new GMC Motorhome by 1987!

Here’s what it (could have) looked like:

87gmcmotorhome

Hot damn.

I bet the first thing you’re noticing is that, like the original 1973 Motorhome, this is a three-axle design, only here the twin axles are up front. What the hell? Well, there’s actually a reason for this, and it’s not unheard of: The British Bedford VAL bus used such a layout, as well as some Mack and GMC tractor trailers.

Chinesesix

This layout is referred to as the “Chinese Six” layout, and while I was afraid the origin of that term might be overtly racist, it seems to just be because it’s reversed from the expected, in the sense that China was thought of as being on the other side of the world, or whatever. I hope it’s not racist, at least.

Here’s how The Bishop explains the logic behind the double front axles:

“This approach allows for narrower, smaller front wheels for a lower floor, as well as better handling, redundant tires for a blowout, and tighter turning circle.  Different sized wheels, different spare tires needed?  Yes, but the advantage here is the smaller-than-motorhome sized front tires used could be more readily available, i.e. the size of pickup/van tires…”

So, with all those axles up front, where is the engine going to go? Well, in 1987’s Motorhome, that’s reversed, too, and even weirder, in some ways:

The 1987 model would still have the air suspension of the 1973 design, but would ditch the FWD system for a rear engine. …better for towing and the elevated power barn area won’t matter since it’s under the bedroom in back.   Likely it would be a new generation Cadillac V8 FWD system stuck in backbut would that be enough power?  Did they have a transaxle strong enough, and if not would GM really invest in special transaxles for as small a run as these might be (at least in there terms of ‘small run’)?  What if, to keep development costs lower, you had two 2.8 or 3.3 liter V6 motors in back…one for each wheel so no differential?  This mock V12 would still probably get better gas mileage than the Cadillac 8.2 liter of the original.

Yes, twin engines! Two V6s are pushing this thing. I suspect that these V6s, normally used in a transverse configuration in other cars, could use existing transverse transaxles, with the inner axle shafts of each engine connected together? This could allow for dynamic engine de-activation to save fuel on highway trips, maybe?

Anyway, here’s a diagram:

Cutaway

Let’s look carefully at this cutaway, because it’s full of great ideas. The radiators are mounted in pods on each side, and flanked by slide-out cargo trays/drawers, though I do wonder if the Bishop may need to sacrifice some of that storage for water tanks? Maybe not.

The hump created by the engines is well-hidden under the big double bed at the rear, and, for an RV, there’s a remarkably large front passenger compartment. As The Bishop explains:

The extra space from the small wheels allows for a spacious front compartment.  I’ve always hated that a great many RVs offer good seating for driver and passenger, but other passengers can’t ride in it like a regular car and enjoy the view with Mom and Dad like they can in the Caprice wagon they left parked at home.  It’s also dangerous as fuck to sit at some dinette or lie on a bed while going 70MPH (Metallica’s Cliff Burton comes to mind).  The journey is just as important as the destination and I wanted to make this thing offer driver and passengers as close to a car-like experience as possible.  Consequently, this would feature two rows of seating that is forward facing for while the RV is in motion..MUCH safer and creating a better travel experience.

I mean, when I crossed the country with my family in an old RV, one of the best parts (for them) was sitting in the living-room-like environment of the RV, but, sure, that’s not really all that safe, so I get this.

The Bishop has really thought through the potential of this front cab-like section, and with proper Captain’s Chairs-type of seating, this can be a true multi-purpose area:

Frontcompart

Lots of clever swiveling and folding going on here, which is what we all want to see most in fictional RV designs, right? It’s great.

“This big front area would become a living room when the thing is parked by rotating the front seats around, or all seats can face forwards to watch TV (either a giant CRT or maybe a projector screen at the windshield).  Or, this space can become another sleeping area by folding down the ‘back seat’ couch (curtains could separate this area from the dining/kitchen space to create a private ‘bedroom’).  Note that I stole a bit from the Imperial Mobile Director by having a removable table that also has padding when folded open to create an extra passenger filler for the rear seats.”

The Bishop was also inspired by 1980s GM’s affinity for dashboard CRT displays, as seen in the Buick Riviera, so he’s specified a dashboard for the Motorhome absolutely slathered in cathode ray tubes:

Dash

Now, rear-view camera systems in RVs that used little black-and-white CRTs were a thing for a while, so that part isn’t terribly unusual, but a multiple CRT-instrument cluster is exotic, with the only car I can think of that used such a setup being an Aston Martin Lagonda. Still, with GM’s experience in mass-producing automotive CRT displays in its Buicks, I don’t see why the company couldn’t have pulled this off.

If there’s one thing The Bishop understands, it’s that the work he does for us here is fundamentally entertainment, and you’ve got to have some crowd-pleasers in there. That’s why this is part of his ’87 GMC Motorhome design:

Skooter

Since everyone seems to expect me to draw some sliding/folding shit, it must be done.  How about at the back, under the spare tire compartment, you have a pocket for up to three slide-out electric GM Skooterz – basically Sinclair C5s on steroids with which to terrorize other campers with or go get beer at the general store on and crash (class action lawsuit here).  You can sit or stand on them (the seat folds up), and they work as JetSkis on water, too…well, no, they don’t…but it’d be a lot cooler if they did.   It only has one front wheel and RWD but GM would still have been able to dial in some torque steer….I crack myself up.

 Oh, and The Bishop knows he needs to please me, too, so we get this detail as well:

Those are 1987 base model Firebird taillights on the motorhome.

Nice.

It’s a shame GMC got out of the motorhome business, because they had such a fantastic start, and, as The Bishop’s alternate reality makes pretty plain here, they could have pushed it so much further. Today’s motorhomes aren’t particularly sleek or advanced or clever, at least not at the levels that most humans can afford, which makes me think there’s still an unfilled hole GM could fill, if they wanted.

But I’m not going to hold my breath. Best to just live in the fantasy world crafted by the fertile mind and pen of our own Bishop of Fictional Vehicles.

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61 Responses

  1. As long as we’re daydreaming…I never could understand why no one has electrified the GMC Motorhome on the Railroad Locomotive pattern – replace the Olds FWD drivetrain with a small Diesel that runs BioDiesel or even re-processed vegetable oil, that turns a generator which charges a battery pack nestled between the frame rails (a la GM’s Skateboard platform), which supplies electricity to in-wheel motors. Since this is an updated daydream, let’s make the the dashboard a Glass Cockpit, including camera fed mirror displays.

  2. Hell, replace the CRTs with LEDs and you’re damn near ready to sell that now.

    I imagine the Bishop having his own sanctum to complete these designs where he puts on an era appropriate vinyl like Purple Rain, wears a t-shirt with an airbrushed BMX bike bought at a mall shop, and lights a candle that smells like a smoked in McDonalds.

  3. Weird… Off the top of my head, I could have sworn that motorhome/assault vehicle was in Spies Like Us, not Stripes. Apparently the two plotlines are so intermingled in my mind that I can’t keep them straight. Guess I’d better watch them both again…

    1. Both were a major part of my childhood! And yes, seeing this article did make me want to watch both again. I always seem to forget how long the pre-action is in Stripes (though quite funny). Spies Like Us just has so many quotable lines. I get the Russian dance song (Soul Finger) stuck in my head all the time.

  4. As someone who grew up in a dustbuster olds silhouette (the Cadillac of minivans) and had to borrow often in college when my shitboxes broke I very much appreciate the side stripe graphics pack, low headlights and general shape. I do however disagree with the firebird tails, they obviously should be the roof/outer line giant monstrosity that on this would be a 12′ long upsidedown L of plastic for each side.

  5. It’s no Starstreak, but this thing is Sweet!

    As to the Powertrain, why not lean into Cadillac’s, ahem, legacy of the time, the V8-6-4? Do a V-16-12-8. The CRTs could have some kind of 8-bit animation showing the cylinder deactivation and maybe an oil pump-jack slowing down/speeding up depending on fuel use. The 80’s tech equivalent of the “Power/Economy” gauge.

    1. There are perenially startups trying to provide long distance Business or First class-equivalent overnight bus services in the US. Off the top of my head, there’s one that runs between San Fran and LA where you sleep in pods like a capsule hotel/Pullman car. There are a couple operating out of DC. One does overnight runs to Nashville with private sleeping compartments, while another (Jet) runs to NYC with Business class-style seats. (More space, individual motion-cancelling suspension, better snacks.)

      Hotel buses are pretty common in Japan

    1. adamrice- it’s more than vaguely similar. I was heavily influenced by that design. They were a great design but the diesel BMW motor and stick were not really what motorhome people wanted. I know they added a raised roof and a GM V6 in back but it still didn’t sell. I figured why not upsize the whole thing.

    2. Nice. A couple of years ago, there was somebody in my neighborhood that had one for sale, it had been decked out with solar panels. It was sweet, but a lot of money for someone who rarely goes on trips. Of course, I fantasized all the places I could go in it, but reality crept in.

    3. Or, predating the GMC Motorhome, was the Corvair based Ultra Van from the 1960’s. There’s a remarkable number of these still around, but only 330 were made. It was 8′ wide, 8′ tall and about 23′ long and still weighed just over 3000 pounds. They were available with 110 or 140 air cooled Corvair engines with a 2-speed Powerglide Automatic.

      1. The small rear engined ‘pusher’ RVs didn’t seem to catch on. The other stick/diesel 20 foot RV was the Winnebago LeSharo , a euro Renault Trafic van based FWD design. It used the whole front passenger compartment of the Renault but added a shovel nose with Buick Skylark headlights. Sold better than the Vixen despite only 66HP. This was replaced by the much more successful VR6 powered Eurovan nosed Rialto.

  6. Small correction, the GMCs used the Olds 455 at first and then the 403 after the 455 went out of production, not Cadillac power. A lot of them have been updated with throttle body EFI kits and overdrive (4-speed) transaxles which makes a pretty nice package.

  7. If anyone is wondering why GMC didn’t continue with its Motorhome after the passenger E-platform was downsized in 1979, it had to do with the Unified Powerplant Package® (UPP®) being redesigned and downsized for smaller and lighter vehicles. GMC used the 455 then 403 Oldsmobile V8 and beefy THM425 gearbox with wider roller chain. For 1979, UPP® was downsized to Oldsmobile 307/350 and Cadillac 368 V8s and wimpy THM325. Neither was up to snuff for heavy vehicle. On the other hand, why couldn’t GMC continue the smaller production of 403, Cadillac 425 (which 368 was based on), or even GMC’s own truck V8 and THM425 for a several more years, hmm?

    Anyway, my family were this close in hiring the GMC Motorhome for our first American road trip with RV in 1977. The hire cost was too high for my father’s liking so he took cheaper and slightly shorter Pace Arrow. “Penny wise, pound foolish” would be the slogan here. The aerodynamically inefficient Pace Arrow consumed much more fuel than GMC Motorhome would. My father ended up paying way more for the fuel, negating the initial cost saving. The family of my classmate’s had one, and I rode in it a several times on the shorter road trips through Texas. It was the most comfortable RV: almost like riding Citroën CX.

  8. I disagree. The GMC motorhome was at its best being FWD with the tandem single wheel rear axles and air suspension.

    I’d argue it’s the best full size motorhome ever mass produced.

  9. The small rear engined ‘pusher’ RVs didn’t seem to catch on. The other stick/diesel 20 foot RV was the Winnebago LeSharo , a euro Renault Trafic van based FWD design. It used the whole front passenger compartment of the Renault but added a shovel nose with Buick Skylark headlights. Sold better than the Vixen despite only 66HP. This was replaced by the much more successful VR6 powered Eurovan nosed Rialto.

  10. My grandparents had one of the original GMC RVs. First big trip I remember as a kid was caravaning out to Rapid City for a week or two in the early 80s with them in that high-tech, sleek seeming machine and us in our standard Winnebago.

  11. Wouldn’t two engine and transmission packages linked by the left axle/output of the right engine connected to the right axle/output of the left engine just send all the torque to the freely spinning connecting piece?
    As I recall Ed Roth’s twin-engine Mysterion had that problem. Well, it had a lot of problems but that was one.

    1. Hugh- actually, it’s worse than that…my idea was to have each engine power a single rear wheel independently, and let GM beta test their traction control systems on this thing. Again, I really don’t know what I was thinking, but that was the dumb-assed dream…the impetus being that GM would not have to do much engine/transaxle development for this short run project…and some of those GM V6s really were good, inexpensive motors.

      By the way, I believe that on the Mysterion, the second engine ended up being just a dummy, hollowed out to hold the alternator and with a belt to allow the running engine to turn the visible moving components on the fake one.

      https://www.motortrend.com/vehicle-genres/big-daddy-ed-roth-mysterion-details-photos/

      1. One thing about not quite synchronized twin engines is that they sound amazing. In your scheme, every time you would turn a corner the engines would settle into a new harmonic. I’d love to hear that. There was another So-Cal side-by-side twin-engine custom that was in theory drivable but I can’t remember who built it. I always enjoyed driving past Dean Jefferies’ place when I lived in a parking lot up I-5 in Valencia and I want to say he built a car like that because he was the most technically adept of the Kustom guys, but I can’t find anything about him building such a thing.

  12. First comment on the new site. Thanks to all for making this a better version of the other place!

    This is a fun exercise! Feasible, but weird in all the right ways.

    I would love to see what a modern version of this would look like… Maybe a GMC RV EV based on a stretched version of the Hummer’s Ultium platform?

    Think of the configuration possibilities of a motorhome with no engine hump. Line the roof with solar panels for trickle-charging the batteries and/or powering electronics? A drive-by-wire driver’s cockpit that doesn’t require mechanical hard points and could move out of the way to make more room for living space when parked? Etc.

    -RBB

    1. Building off of this idea.

      Take a Diesel (or hydrogen if you want all the ESG points) generator that would power this beast on the highway, and charge your batteries if you’re boondocking somewhere without sun.

      Update the AC units to hyper efficient minisplits with the units mounted to the rear to lower the clearance, give space for built in solar panels, and make the machine more aerodynamic.

      I’d say I’d buy it, but lets be real that’d cost north of $300k and I’m not made of money

  13. I miss my old GMC motorhome. Seems like a pretty good re-imagining. I think the keys to making it a true homage to the old one would be large greenhouse, low floor and great drivability.

    My 78′ drove so much better then most modern class A’s.

    The huge windows also connected you more to your environment. The cozy space felt more like luxury camping than a hotel on wheels.

    I am not sure about the 4 captains chair idea. The original had 2 captains chairs that would swivel to become part of the “living room.” One common arrangement would be to have a couch and a dinette table each had seat belts for driving and each could be converted into a bed (or bunk bed).

    If we are thinking futuristic some sort of diesel/hybrid drivetrain could work, with a focus on efficiency. I like the idea of moving the engine to the back, traction was not great on the FWD layout. People have been working on a clean replacement for the old Toranado drivetrain for a long time, and noting has really ever been come up with.

  14. Love this design. That passenger area with a modular layout seems somewhat inspired by the Renault Espace MK1, save for the twin bed setup which sadly wasn’t possible (that one seems more inspired by the Twingo).

    In the Espace you could slide the front seats all the way back, turn them around facing the rear seats and recline them in a way that allowed you to sleep somewhat comfortably, but the seats didn’t fully recline so it was impossible turn in into a flat surface and there was still a sizeable gap between the front and rear seats. It was ok though, I used to have an Espace Quadra that I used for camping at music festivals for a few years and it was 1000x better than a sleeping in a tent on the ground.

    https://preview.netcarshow.com/Renault-Espace-1984-1600-05.jpg

  15. Yeah, this is cool! My dad borrowed an original GMC which was a company vehicle back in 79 or 80 for a fall trip in New England. It was simply amazing to this pre-teen. The “dining room” in the rear was a queen size bed. We had plenty of room for the 3 of us. We would pull into an RV park or stop for gas and it would just attract a crowd! The air suspension was pretty cool to level out the rig, instead of outboard jacks.

    Yes, I sat at the table while moving, I had homework to do, but remember this was a time when no one wore seatbelts. We had a 70 Town &Country wagon and with 4 sisters I usually sat in the space between the 2nd and 3rd row seats.

    I’ll take one of these in brown with an orange stripe. Ahh, the memories!

  16. I really feel like, if this had happened under Roger Smith, they’d have wound up doing something insane, like sticking in Cadillac’s HT4100 – 0-60 would have been measured with a calendar, and the bustleback Seville would have seemed a paragon of durability and reliability compared to what pushing around a heavy motorhome would do to one of those. They’d build it for 4-5 years, get loads of bad press over engine failures, spend more than the original development cost re-engineering it with the twin V6s that turned out to be surprisingly reliable, then cancel it entirely after a year or two, because that’s how ’80s GM worked.

    1. Ranwhenparked- how did you read my mind?? That’s the exact backstory I had imagined for this thing, except mine involved cases of HT4100 engine fires from valve cover gasket oil leaks onto the manifolds and a class action resulting in head gasket replacement and cooling system retrofits.

      1. I’m sure that would have happened to. That company was a complete and total disaster during that period, it’s amazing they managed to lurch all the way into the 21st century before collapsing in bankruptcy

    1. Eh, fuck it, why not. Seems fun.
      BUT I GET TO PICK THE DRIVELINE. And we are not doing twin engines. Absolutely fucking not. You’ll get a Detroit Diesel 6V-71T with an Allison auto and you’ll be happy about it, because that will actually run right more than once per century.

        1. GM did this with the Scenicruiser buses for Greyhound!

          “Twin DD 4-71 four cylinder engines were mounted longitudinally, side-by-side, connected together with a fluid coupling whose output was fed to a solenoid-operated clutch, a three-speed transmission with synchronized second and third gear, and a two-speed auxiliary transmission to split the gears, for a total of six gears.”

          Reliability was horrible and Greyhound replaced the engines with a single Detroit Diesel 8-71 V8 when those engines became available.

          Source: https://www.curbsideclassic.com/curbside-classics-american/curbside-classic-gmc-pd-4501-greyhound-scenicruiser-everybodys-favorite-bus-except-for-greyhound-and-gm/

  17. Alright.. lets start off with the Basics:
    1. The “ancient” and or crude pic above.. is a 1971 Winnebago Indian in the 25-26′ models. I believe they also had a 31′ with a Chevy 454 and a 3spd with Overdrive. They had Chieftains and they were a bit longer.

    2. In my past life — yes, I have been around and seen some things, I drove one of these when they were 20-30yrs old with family of mine from one end of the Eastern Seaboard straight into Canada. One of the.. “cute” things about the Winnebago was.. it could sleep 6. You could sleep 2 in the back, 2 in the dinette set that folded.. and 2 above the driver area. The bed slid down on a Cantilever of sorts. When I mean, it could sleep 6.. I mean it could sleep 6, as in not just have 6 people sleep in it.. but 6 people functionally live AND SLEEP in it for a period of a week +. So all of their gear, clothing, food, water… entire human needs met.. by one vehicle.. for a week. Add in pets.. and lets just say… all 6 people have to be GOOD friends.

    3. If the RV from GM couldnt do that.. then they are missing something. If the re-iteration of the RV from GM cant sleep 6 and have enough human capabilities.. to last a week.. then something isnt right. Also remember: ya need a fullsize fridge, a pantry with dishes and other stuff, a generator, batteries to operate the RV and the vehicle seperately. Ya going to need tanks (grey, black and freshy water) as well as valves to control it all. not to mention a bathroom big enough to be at least 3-4′ sq.

    4. Ive been playing around with floorplans, Isometrics of Winnebagos and or RVs for the better part of 20+yrs and its incredibly difficult to put this all together.

    P.S
    It is fun… to see a Dual Steer RV, but the seating for 5 is wasting a lot of room. On top of.. we havent even gotten into Slideouts…

  18. Instead of the goofy dual engines driving a wheel each, I’d give it a hybrid system.

    Most of the power is needed just to get the beast rolling, and then less power is needed for steady state driving. Start in battery and engine mode, cruise in battery mode until the engine needs to kick in, park and let the engine charge the batteries while you set up camp, and then enjoy the quiet of living off of batteries for the night.

      1. Well, it is about the same color as the T.A.R.D.I.S.! Yeah, I had the Skooter idea after I had already done the layout and a bit of wishful thinking. Would likely need more rear overhang…. and thinking the spare tire(s) would need to go vertically behind the taillight panel.

        Front spare might need to go under the front floor…BUT my stupid idea was to have NO front spare…if you get a flat tire up front simply raise the affected tire with the air suspension and drive on three front wheels until you can get it fixed. Here’s a still from a Chevy Citation commercial where it towed a boat with no rear wheel:

        https://www.airforums.com/photos/showimage.php?i=33843

        I know…probably wouldn’t work…but would like to try…

    1. Remember, this is supposed to be a 1987 version. Hybrids weren’t a thing back then. Besides, with a twin engine design, instead of cylinder deactivation, you could have engine deactivation. Get up to cruising speed, put one trans into neutral, and turn its V6 off.

      1. Honestly, I wanted to use the contemporary Cadillac V8 FWD system but there is no way that would have enough power/strength. More realistic to have a big block GM motor mounted longitudinatlly in the middle, a short driveshaft, and a live axle like a giant Previa; but I want to keep the roofline low, at least in front like those GM Scenicruisers of the 40s-50s.

      2. The technology was around, ZOE Motors (the stillborn American Reliant importer, who might have been more of a money laundering scheme than an actual company) developed a gas-electric hybrid version of the Reliant Rialto, of which at least one running prototype was built, and Reliant themselves, in partnership with Lucas Industries, built a hybrid show car in 1982. But, it was all still very experimental and way too much work to productionize in the era of historically rock bottom oil prices

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