The Autopian has been sorta-shopping for an RV for quite a while now, and part of the reason we haven’t pulled the trigger is that we’re looking for something special. Something stylish, vintage, reliable, spacious, and most importantly: something with a stickshift. It may come as no surprise to many of you that most RVs are automatic; America gave up driving the stickshift many decades ago. Still, if you look hard enough, you will find manual transmission RVs, and these two that I’m about to show you are the most compelling in my eyes because those standard transmissions are hooked to unkillable motors.
The one thing I care about when it comes to an RV is that it works. I’d rank “removing and rebuilding an RV’s engine or automatic transmission” somewhere between “debate with Tesla YouTubers whether the Model Y is the greatest car of all time” and “rebuild an automatic transmission valve body works” on the list of activities I want to do anytime soon. As such, the only RVs that remotely intrigue me are ones with manual transmissions (which tend to be easier to remove and way easier to rebuild than autos) hooked to unstoppable motors.
Recently, two RVs have popped up for sale in the LA area, and not only are they both relatively affordable, but they both feature engines known for Never Dying. The first is a smaller RV called the Clark Cortez:
This is a machine developed by a Michigan-based company named Clark, which is known for its forklifts, and also for pioneering those tractor-like tugs you see at airports. The Cortez motorhome is a compact front-wheel drive cruiser outfitted with a standard 225 cubic-inch Chrysler slant-six mated to Clark’s own four-speed manual transmission. And it’s gated!:
My colleague Mercedes Streeter has already written the full story of the Clark Cortez, so read that if you have a chance. Here’s a quote describing the vehicle’s basic layout:
According to Clark, 60 percent of the camper’s weight rides on the front axle for handling, traction, and stability. In terms of motorhome equipment, everything that you’d expect to be there is present. It sleeps four adults with a floorplan that includes a full kitchen and bathroom with shower and toilet. The coach’s engine feeds from a 25-gallon fuel tank and there’s storage for 30 gallons of water onboard. The brochure doesn’t note anything about waste capacities.
I’m a huge fan of the Chrysler Slant-Six. I daily-drove a 1965 Plymouth Valiant for an entire winter in Michigan, and I never had any issues with the Leaning Tower of Power, despite me having bought that old rustbucket for just $2 grand. The motor ran like a top!
If you don’t believe me, give this a watch!:
So I’m already sold on the Clark, even if I know it’s got more weight to carry around. The Cortez weighs 7,000 pounds, or over twice what my Valiant did (it helped that my Valiant had undergone some salt-induced weight reduction).
Anyway, here are some more photos of the Clark from the Facebook listing. The thing needs work — with rust on the roof, insulation missing, and a dashboard that looks like it was submerged in the ocean for a bit — but at $5,800, maybe it’s still an OK deal?
Still, even if that Cortez isn’t perfect, its trump card is the Chrysler slant-six. It’s a truly unkillable motor, and the prospect of that being hooked to a beefy four-speed built by a company known for its industrial machinery — I like it. You know what else I like, though? Like Clark, it’s a company that starts with a C. It’s also based out of the midwest, and it’s also in the heavy machinery business. I also spent a summer there working as an Advanced Concepts Engineering Mechanical Development intern.
I’m talking about Cummins.
That’s what you’ll find in this 1971 Grand Coach Crown RV conversion (clearly, this was once a bus). The engine is a Cummins 220 “pancake motor.” It’s mid-mounted, and hooked to a Spicer five-speed (some had Eaton Fuller 10-speeds; the seller on this one says it’s a five-speed) with a huge stick wrapped in a hilariously tubular boot:
And the living quarters appear to be in decent shape, too:
What do I know about the Cummins NHHS 220? Not a ton; it’s 12-liters of fury compared to the Clark’s 3.7, and it makes over 600 lb-ft of torque, which is a good thing, because this camper is humongous.
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It’s a fascinating motor — six cylinders sitting on their sides, all mounted in the center of the coach. This big-rig motor is unstoppable according to the commenters on Barn Finds, with HotPotato writing:
The Crown Supercoach is indeed iconic…and not just for the retro-future mega-Twinkie styling which was unchanged for 40+ years. Most school buses are built on medium-duty lowest-bidder beer-truck chassis. Crown built its own chassis, and every mechanical component installed was from the world of 18-wheelers. That’s the reason for the mid engine and the tall floor: there’s literally a semi powertrain under there, cleverly turned sideways to save space. It can be serviced anywhere with standard 18-wheeler parts, and it will outlast any other school bus on the road: a million miles is nothing, and literally the only reason these bad boys were retired after decades of service was because emissions rules required it.
Here’s what commenter Dave Wright had to say::
They moved 80,000 GVW trucks all over the country even before freeways. Geomechs is on the money as usual…….220 Cummins built the prosperity we have today moving 80,000 of whatever wherever we needed it.
And here’s a quote from skoolie.net:
I would guess it’s most likely a Cummins 220 HP (non-turbo). If it runs well it’s a very fine engine and with
a 10 spd. behind it it’s very close to a perfect combination. The NHH-220 specs: 743 cubic inch 220 hp @ 2100 rpm,
606 lbf/ft TQ @ 1600 rpm. The key is that the engine only produces about 600 ft/lbs of torque and the transmission
is built to take 900 ft/lbs and pull 80k lb. trucks all day long. You just can’t stress that transmission enough with that
engine or fully loaded Crown to cause any real heat build up.
Cummins itself writes about this “Pancake” motor on its website, noting that in 1954 it powered America’s very first diesel school bus:
The Crown Supercoach was the first diesel-powered school bus, with a Cummins NHH-200 hp horizontal ‘pancake’ engine mounted midship underfloor. The 12.2-liter diesel was ideal for hill-climbing and enabled the chassis to add a third axle, increasing to 91 seat capacity for school districts with growing student populations. Known as the ‘royalty’ of school buses due to exceptional build quality, the 40 ft. long Crown featured 26 roll bars in the roof for added strength and safety.
Clearly, these buses were beasts. But they also weighed at least 20,000 pounds.
So which of these — the lightweight slant-six “Leaning Tower Of Power”-equipped Clark mated to a four-speed or this huge Cummins-powered Crown hooked to a five-speed — do you think would be easier to maintain and last longer?
Topshot: Facebook Marketplace/Cummins/Plumkrazygarage
The Crown Supercoach is a part of the Autopian RV/Bus Expanded Universe, too!
https://www.theautopian.com/this-vintage-crown-bus-has-a-mid-mounted-diesel-engine-a-manual-transmission-and-a-wonderful-interior/
If it were my money, I’d get the Crown. Those old buses were built to last and the conversion looks like it was done professionally. Let Sheryl work her magical cleaning powers and we could sleep in it almost right away.
On the other hand, the Clark was built to be a motorhome from the start. It was also built with an all-steel body for longevity. Unfortunately, this one hasn’t lived the best life. We’d have to gut that roof. Then, there’s the FWD powertrain. This isn’t the Oldsmobile UPP with a Chrysler engine, but a more bespoke setup with parts that’ll be hard to find. Ignoring all of that, the poor engine has a lot of steel to move.
My vote is for neither of them but then again I know this writer as some sort of SM guy with a never ending and growing list of projects so I’d say ; perhaps save the potential $10+ amount of money you’re going to spend on this and book 50 days of nice hotel rooms @ $200 a night.
By the time you actually used up all those nights it’s a couple of years further down the road, both these rotting carcasses will have been recycled as they should have been a decade or two ago and you will have plenty of opportunity to get something new, waterproof and electric to go everywhere instead of being kicked out of every scenic spot because you’d be bringing a gas engine spewing more toxic exhaust fumes than all cars of the nearest medium sized town together nor are you covering a square mile of trees with enough soot for them to stop doing photosynthesis for a month.
The Cummins wins here, but you’ll need a Hazmat team and an exorcist before anyone should attempt entry…
I can smell that Crown through the pictures.
Both – the Cortez is small enough that the Crown can tow it, and with both a Smart and an i3 attached to it, both Mercedes and David will be happy. And the symbolism of the Cortez representing the Crown in its conquest of parts of the former Spanish colonies of the American West will be the brutal, bloody, genocidal icing on the cake.
You couldn’t park that bus in 70% of the cool campspots in CA so, include that thought.
Sorry David the Slant 6 isn’t so much reliable as the entire Dodge/Plymouth cars that used it just failed quicker than the motor. My 2 brothers and myself owned a Valiant and 2 Darts in the early 80s. We maintained them because nothing else to do. My Valiant had a tendency to shut off on left hand turns, not electrical just couldn’t maintain fuel pressure on left hand turns. My brother’s Darts didn’t fare better.
The Crown definitely. It’s literally built like a tank and that engine can be rebuilt with a hammer and a 1/2″ drive socket set. Also it,unlike the other one doesn’t look like it’s been left in a swamp for 40 years.
Maybe we need to let David’s cats make the decision.
Or his storage yard.
They probably wrote the article. There is a theory put 100 monkeys in a room with 100 typewriters for 100 years and they will write the entire works of Shakespeare. So David’s cats writing this? Not a surprise. JK
honestly are you trying to make for an interesting article or a real question? Because it really isn’t a contest. If you guys are really an automotive journalism company looking for an RV it’s the diesel crown all day long, its big enough for several members of a professional staff to share, it can TOW ANY car or truck you guys bought across the country and need to move to California HQ etc. The Slant 6 thing is just more David Tracy fun for him to play with and sand rust off of
Hey I submitted far better RVs problem is too reliable and dependable. Though DTs recently found common sense I’m surprised he even asked this question.
Diesel coach, ten thousand percent. I drove diesel motorcoaches for 5 years and got plenty of opportunities to compare them to gas powered RVs, it’s night and day difference. A proper coach is built well and will keep chugging for a literal million miles plus while the dinky gas ones are always overburdened and will break early and often while getting horrendous fuel mileage.
When comparing the Crown and Cortez specifically, the answer becomes even more obvious to me. Rust and water issues should remove the Cortez from the running right away, but the Crown’s issues are much easier to fix with much lower risk of the problems snowballing as you dig deeper. In the end, the Crown will be a much more solid platform for any changes you want to make and will keep delivering on anything you ask of it. Any time it does need work, anyone and any nearby shop that works on semi trucks will be able to fix it. (These are everywhere, if you consider how common semi trucks are) Plus, with a diesel it’s pretty easy to hook up a trailer with the next holy grail project car on it so you can adventure and bring home goodies!
Which of these will be easier to maintain and last longer? As The Fine Article states, the Crown “can be serviced anywhere with standard 18-wheeler parts” and it has much better bones. Case closed!
+1
More or less what I was thinking.
I saw a Lil Bugger based on an early ’60s Beetle driving past the Burbank airport on Friday. I vote you chase that down and make ’em an offer.
That Clark Cortez looks really rough for that price, and I don’t think you have the time anymore to spend fixing that up to the point that it’s going to hit the road for a long roadtrip. The Crown looks like it needs needs a lot less attention, and the platform is made to cover hundreds and hundreds of thousands of miles. It looks like it just needs a carpet replacement cosmetically (or maybe just a really good cleaning, but I’d replace the carpet with some LVT planks or something that isn’t going to capture dirt. It may have been a conversion, but that Crown looks like it was a very professionally done conversion. If parts availability isn’t an issue, the Crown would be my choice.
The Cortez is awesome for its uniqueness, but unfortunately the roof and ceiling damage say stay away unless you want to peel off the entire roof and rebuild it. If you don’t you’ll be fighting leaks and problems forever.
The Crown’s interior needs plenty of TLC, but that’s not really all that hard to do. (Especially not compared to fixing the Cortez’ roof.) Mechanical and suspension work on the Crown shouldn’t be any worse than any other truck or bus running gear work. Big parts, big tools needed, and some big price tags for big hunks of steel, but not too scary as long as it’s not rusty and/or neglected. Of the two, the Crown is the much more likely candidate.
David,
You’ve done enough resurrections to know that rust is forever. This alone should help make your choice.
With the culling of his Michigan fleet and the acquisition of SoCal cars DT is probably getting nostalgic about rust.
I’m starting to worry David may be experiencing multiple personalities. He recently writes about moving on from projects he won’t finish, and wanting to grow and do different things with his time (LA David). Then he throws a giant rust bucket, that is rusting from the opposite side of the vehicle he’s used to (Detroit David).
The Clark looks like you’ll get impromptu showers inside every time you pass through some rain. That could actually be a feature and not a flaw. The Crown looks like a bigger project with much higher operating costs. I just want you guys out on the road, and hopefully making it to the East Coast, so just get one!
As a Plant & Equipment Manager I had a bus with similar rust around the roof transferred to our branch. After taking it to a panel beater to have the rust cut out, we decided to sell it. The more they stripped it back the more rust they found, it was definitely not worth repairing. Don’t waste your time and money with something like this. As mentioned by someone else, the type of engine should be dictated by its intended use, if it is going to be infrequent short trips, don’t buy a diesel, they need to run hot to remain efficient.
I’ve had a Cortez. Run away. The slant 6 is begging for mercy in that heavy steel body.
And the rust – there will be 10x more hidden. Parts are hard to come by and much of the drive train is fragile.
I’ve made a lot of terrible automotive purchases in my time and the Cortez was at least top 5. They are just awful in every way, don’t let the charming style trick you.
If you MUST have a Cortez the later V8 ones are much better.
Bigger is better. More space to bring more readers on more adventures. You can surely cook up some mental stories, videos, and streams with a ton of people fixing up and partying around in a huge Moho
The Crown, but just for personal nostalgia. I grew up in San Diego and all the schools I went to through high school used Crown buses. Some 2 axle, some 3. I can totally hear the Cummins in my mind. Also makes me think of the green seats inside. I can still feel the weird textured vinyl or whatever it was.
Yeah I’m thinking Cummins is the way to go. More room and it will actually move faster than a glacier
They are both unique, and I really like Chrysler and the Slant-Six but this Cortez will need a lot of work and doesn’t have as much room…so in this use case I would definitely say the Cummins since diesels last way longer and it’s bigger (That’s what she said…)
The answer depends on what you’re gonna use this for. Drive within 50 mile radius and park at car shows? I’d go with the fun factor Clark. Run across country and accumulate thousands of miles per year? Crown for sure.
But either one will be a time sink/money pit if you want to upgrade to current standards and maintain it at full functionality.
You need the Crown. It’s an oversized vehicle, for an oversized task. The drivetrain is designed to move things that are as big as, or larger than, what it’s being asked to move in this particular situation. The slant-six may be great in a ’65 Valiant, but this ain’t that. Besides, Mercedes has the appropriate CDL.
The second choice for this endeavor would be Jason’s guest room… cottage… whatever it is today. Just because I’ve been hearing about it being immobile since… and it should move again.
I agree. Cortez is cool but there is something to say for an over built, under stressed rig.
Weirdly, I don’t have a CDL! But both of these have RV registrations so that part wouldn’t be much of a problem.
That said, you make me want to put David and Jason behind the wheels of big buses and see if they take out signs and curbs. 🙂
Last I checked, class b cdl is just a test. And if you are using it as a company vehicle instead of personal, you may have to have one.
Wait a minute, I knew that. You’ve written about that. D’oh! Wasn’t thinking…
I too would like to see what Jason and David would do behind the wheel of a bus. Would it be this one, yours, or someone else’s? Considering the condition, this one would probably be the better choice for taking out signs, curbs, etc…
Oh, and immediately after posting my previous comment I felt like a jerk for volunteering you to drive.
The Cortez is a cool looking rig, but the roof may be about ready to leave the chat – look at the bubbling above the gutters. That said, the 225 is a solid, dependable motor. I had a few cars with the Leaning Tower of Power and never had a lick of trouble with any of them. When I worked at Dodge dealership in the 70s we had a steady stream of 225s in the shop every day and rarely had to do anything to the engine beyond tune-ups and some carb work. But that roof would scare me! The Crown is probably unstoppable, as long as you know a heavy truck mechanic to tend to its needs. Being that you’re based in California, does emission testing that Cummins come into the conversation?
The Cortez has a real je ne sais quoi that the bus just doesn’t, snazzy stripes notwithstanding. Also, the Cortez would be easier to navigate in more places than the bus.
And a commenter, Shooting Brake, pointed out that Vincent Price had a Cortez which is indeed a compelling reason to go with the Cortez, ha (if you do some reading about Vincent Price you’ll see what a genuine mensch he was 🙂 this aggregation of tweets by a Vincent Price expert is as good a place as any to start: https://www.upworthy.com/vincent-price-was-a-real-life-hero)
People have been pointing out the issue of parts availability with the Cortez but it seems like the bus would be more of a nightmare to work on, that is, the Cortez seems more DIY-friendly whereas the bus would require specialized equipment and specialized knowledge. It may not be directly comparable to be talking about double-deckers but this YouTube channel https://youtube.com/@LondonBusRestoration?si=Fe0TV4TNd2wEU_RS gives a good idea of what it takes to work on buses. While they could perhaps use better video editing their videos provide some insight into the nuts and bolts (ha) of keeping vintage double-decker buses running and can be quite worthwhile watching.