Okay, here we go. This will be the start of a long drive. Strap in. Maybe order some take-out first.

Three years ago, I went to Southeast Sharkfest for the first time. It was held that year in Spartanburg, at the BMW plant. While I’d owned an E24 before—a 1985 U.S.-spec 635CSi with a stick and sport seats—I’d never seen a whole field of the big coupes together before, and there’s nothing like a hundred schooling sharks to help you notice the subtle evolution over the years, and the differences between the domestic and European editions.

I already knew that the early E24s were based on the E12 5 Series chassis, and switched to being based on the E28 in 1982—the 1983 model year for the United States. I also knew that the Euro cars weren’t saddled with the big obtrusive 5-mph bumpers the U.S.-spec cars had. But I had never actually seen an early Euro in the flesh until Sharkfest. Someone—it may have been CCA National Capital Chapter vice-president James Laws—had an E12-based Polaris (silver) Euro 635CSi, with a black sport interior and black stripes on the sides of the car, including on the air dam.

I just kept staring at it. Those close-in Euro bumpers completely change the look of the E24, clipping half a foot off the length. On this particular car, the combination of the bumpers with the air dam, the silver paint, the black stripes, and the black sport interior did it for me in a visceral way. We’re talking weak knees and mumbling. I resolved that, if I found a shark configured that way, if it was anything close to affordable, I’d try to make it mine.

A year later, an identical-looking early Euro 635CSi showed up on eBay, Craigslist, and the bigcoupe.com forum. The seller was asking $8,500, partially because he’d sprung for some expensive goodies like a newly-refinished set of BBS RA wheels, an M steering wheel, and an Optima battery. Unfortunately, the car had issues; it had lost its original M90 engine and dogleg gearbox, replaced by a U.S.-spec M30 motor and overdrive tranny. And it had 220,000 miles on it. And the gas tank leaked. And the wipers didn’t work. And from the look of the inner fenders, it was evident the car had taken a pretty good hit to the front. And—it had no air-conditioning. For all those reasons, my left brain ruled it out.

But man, it had all the visual characteristics of the car that had blown my skirt up at Sharkfest, and my right brain kept guiding me back to the ad and staring at the pics. The car was in Berlin, Connecticut, which was close enough for me to have a look.

When I saw the car in three dimensions, I found it even more compelling than it was in two, and when I drove it, leaky gas tank and non-functional wipers notwithstanding, there wasn’t really that much wrong with it. But $8,500 was way too much money, considering all of the demerits the car had. I walked away. Besides, my own advice is that if you want a car with working air-conditioning, you should buy a car with working air-conditioning; it’s ridiculously expensive to retrofit or resurrect it if you have to pay someone else to do it. And on paper, there are there are plenty of sharks in the sea. (Sorry; that was really bad.)

Of course, there aren’t plenty of early Euro sharks in a particularly compelling color scheme within a two-hour drive of the portion of the sea in which I swim. I couldn’t put the car out of my mind. Its pull was so strong that I was willing to—gasp!—forgo air-conditioning. The car was cool enough without it. Besides, I, who have gone to truly ridiculous lengths to either install or resurrect air-conditioning in a variety of my vintage BMWs, could do it again.

I negotiated with the seller over a period of several months, and eventually got him to sell me the car without the goodies he’d bolted into it. I went down to Berlin with a set of wheels, a steering wheel, and a battery, forked over $3,750, attached the parts, and towed my new silver Shark home. I soon put a set of 17" BBS RC090s on it, which I like almost as much as the RAs that I passed on.

That first winter, I fixed the leaking gas tank (or so I thought; long story) and the wipers. I had the best intentions of at least starting the a/c retrofit, but life and other projects intervened.

In 2016, I drove the car back to the scene of the crime: Sharkfest, which that year was in Chattanooga. As the event was the weekend straddling April and May, the 750-mile drive would be in late spring, and I told myself that perhaps I would be okay running without air-conditioning. And I was—until I got about 150 miles from Chattanooga. The temperature topped 90°F. I hit standstill traffic on the Interstate. I wilted. I resolved that the next time I made a long trip in hot weather in the shark, it would be as nature intended it to be: cold-blooded.

Now, the recipe for retrofitting a system into a vintage car isn’t really all that bad. I cover it in my first book. But the newer the car, the worse it is, as the dashboard and under-dash area become more complex, and the connection between the under-dash a/c components and the rest of the car becomes progressively more intertwined. I’m not sure that I’d want to tangle with it on anything much newer than a car like my ’79. But looked at from 10,000 feet, the project breaks up nicely into the following chunks.

  • Find an air-conditioned parts car and buy every interior a/c piece—the evaporator assembly, console, switches, relays, wiring, any duct pieces and little brackets, and any special hard hose lines that are needed to cleanly route the plumbing behind the glovebox. You don’t really need anything from the engine compartment (compressor, condenser, fan, hoses, receiver-drier), as you’ll be replacing all of that with new and improved components.

  • Unless you know beyond the shadow of a doubt that the evaporator assembly was out of a car that had working a/c, and that you’re going to be using the same kind of refrigerant and oil that was in it, you’re strongly advised to disassemble the evaporator assembly and flush it out, and while you’re in there, you probably want to replace the expansion valve.

  • Procure a compressor and the bracket needed to mount it to the engine. The cost-effective way to do this used to be—and pretty much still is—to buy a Sanden 508 or one of its inexpensive Chinese-made clones and a BMW-specific mounting bracket, but it has become way more complicated than it used to be (we’ll get to that). Fill the compressor with the oil that’s appropriate for your choice of refrigerant (we’ll get to that, too).

  • By a combination of careful measurement and sanity-checking your results on enthusiast forums, identify the largest parallel-flow condenser that will fit in the nose in the car (last week I wrote about doing this on my 3.0CSi). Source the biggest cooling fan you can for the condenser. Mount the condenser and cooling fan in the nose of the car.

  • Remove the old console and install the evaporator assembly. This is the worst part of the job, as it usually requires drilling holes in the firewall for the hoses, and a hole in the transmission tunnel for the evaporator drain. (Satch says to use chassis punches, not hole saws.)

  • Find a convenient mounting location for the receiver-drier. Then have hoses made, or buy a crimping tool and make them yourself, and connect the compressor, condenser, drier, and evaporator.

  • Wire up the system. You need to make it so that when you turn on the a/c switch (which is generally the switch for the fan in the evaporator assembly), it turns on the compressor, and, via a relay, also turns on the condenser fan. For a car like a 2002/E3/E9, you may be running new wires to the fuse box, but for a newer car like an E24, the a/c control panel may plug directly into the existing climate controls.

  • Test for leaks, repair as necessary, then evacuate and recharge with the refrigerant of your choice (long topic there).

So, in pursuit of the first bullet, in order to procure the under-dash components, I needed to locate an E12-based Euro 635CSi or a U.S.-spec 633CSi that was being parted out. $300 rotted E24s aren’t quite as ubiquitous on Craigslist as they once were, and besides, I didn’t really want a parts car in my driveway (I live in one of those tony Boston suburbs, ’member?). I went round and round last winter with a guy on Craigslist advertising a rusty 633CSi that he wanted gone. He kept threatening to have it crushed. I offered him a few hundred bucks to come down to Providence and pull out what I wanted, but he only wanted to sell the whole car. I never took the bait (or the parts).

Last spring, BMW guy with E24 a/c parts #1, Mark Pepke, called me, saying that he’d read about my desire to condition the shark, and that he had a few E24s he was parting out that could generate the pieces I needed, and he could box it all up and ship it to me. “Awesome,” I said. “Let me know what we need to do to start the process.” Somewhere between my 58th and 59th year on this planet, however, I forgot who it was who had called me (rather rude, actually, for him to make a personal phone call rather than send an e-mail where I could perhaps search for the topic and recover the contact info).

So when BMWgwE24acp #2, Jonathan Stupar, put up a post on Facebook saying that he was parting out an early Euro 635CSi, I eagerly asked if the a/c was intact. Indeed it was. I asked Jonathan what he needed to get to pull out every interior a/c component, photograph the removal, and pack and ship everything to Boston. We both circled around each other electronically for a week without either of us mentioning a number or firmly committing to a deal. Finally I asked if $200 shipped was enough to do it, and he said yes.

Less than a week later, two rather large boxes arrived on my front porch, and I began sorting through what Jonathan had sent me, and sourcing the other new needed components.

So the Great Shark Conditioning Project is on. As I write this, August is closing down. If I whack away at the project and don’t get distracted by life, the RV, the dead Lotus, and a thousand other things, I should have it cold by the next Sharkfest.

(Next week: The ins and outs of mounting a Sanden 508 on an M30 engine. Probably.)—Rob Siegel

Rob’s new book, Ran When Parked: How I Resurrected a Decade-Dead 1972 BMW 2002tii and Road-Tripped it a Thousand Miles Back Home, and How You Can, Too, is now available on Amazon. Or you can order personally inscribed copies through Rob’s website: www.robsiegel.com.