Cold War Engine Swap: Meet the 1963 Buick Wildcat With an A-12 Archangel Start-Cart Engine

From A-12 Oxcart to ’63 Wildcat: this Nailhead V8 has had an interesting life, to say the least.

byPeter Holderith| UPDATED Jun 25, 2021 3:40 PM
Cold War Engine Swap: Meet the 1963 Buick Wildcat With an A-12 Archangel Start-Cart Engine

With a top speed of Mach 3.35, or 2,221 mph, the Lockheed A-12 "Archangel" or "Oxcart" is the fastest air-breathing jet ever built—even faster than its larger two-seat cousin, the SR-71 Blackbird. But getting an Archangel into the sky is no easy task. Spinning up its massive J58 engines takes a lot of grunt, which is why hugely powerful "start carts"—comprised of two American V8 engines and two automatic transmissions with a single output shaft—were created to turn the engines over and get them to idle speed and ultimately keep the CIA's private air force of A-12s in the sky. 

Today almost all of these carts, known as AG-330s, are in museums, standing silent forever with the planes they helped start. But more than a decade ago, an engine from one of these carts escaped into private hands. After spending most of its life fighting the Cold War, a Buick 425 lifted from an AG-330 is finally making its way into an actual car after years of uncertainty. This story is without a doubt one of the most interesting engine swap tales you'll find, and the car it's going in—a 1963 Buick Wildcat convertible—is equally special.


Really, it's surprising any of the engines used in AG-330s survived at all. The two V8s were mounted side by side in the cart complete with cooling systems and a few vital accessories. Then they were mated together rather crudely with a massive foot-wide rubber belt. The belt was in-turn hooked up to a 90-degree gearbox which got the engine output facing up in the right direction. This output could be extended vertically into the engine nacelle of the A-12/SR-71, at which point it would spin up the J58, sustain the RPMs (hopefully) long enough for the engine to fire, and then fall out once the jet power was sustained.

This didn't always go to plan, though. Sometimes the engines would still be cold and wouldn't like being revved up to redline. Sometimes the J58s wouldn't light, and multiple restart attempts were necessary. On multiple occasions, V8s were grenaded in the name of operational readiness. As a Blackbird crew chief we spoke to will later explain, he was "involved in the deaths of several 425s." Before we get to any further descriptions of mechanical carnage, however, let us tell you how this cart actually escaped a museum. It's an interesting story by itself.

A Stolen Oxcart

After a hard life being punished by Archangel ground crews, the engine's journey into private hands began back in 2007, when the CIA decided that for its 60th birthday, it wanted a new lawn ornament put in front of its Langley, Virginia headquarters. More specifically, it wanted one of its A-12s back. There was a problem with that, though: these incredible aircraft weren't exactly just in storage somewhere. Just 15 A-12s were built with six lost in accidents over the years. The nine remaining were all prized museum pieces, so for the CIA to get its birthday gift, it became a matter of which archive of aviation history was going to lose its crown jewel.

In the end, it was decided that the CIA's bird would be taken from the Minnesota Air National Guard Museum, a decision that broke many hearts at the time. Ultimately, though, the A-12 was still government property, and the government could do what it pleased with its property. It was disassembled, shipped across the country, and re-assembled in Langley.

Smithsonian National Air and Space Museum via YouTube

Fast forward to 2011, and the museum had been without its A-12 for a few years now. It was not, however, without the AG-330 start cart matched to that very aircraft. Having no A-12 to park it next to, the museum decided to sell the engines out of it. This was a relatively straightforward process, but there was a problem. After a troubled existence cranking over massive jets, one of the V8s turned out to be completely seized. That one wasn't worth anything to most people. The other engine, however, was still in OK condition. It was removed without much fuss, put up for sale, and sold for just $800 along with its Dynaflow transmission to a user on the Jalopy Journal forums. Yes, this guy bought a start-cart Buick 425 matched to the A-12 mounted in front of CIA headquarters, serial number 60-6931, for $800. (I actually wrote a story about the whole ordeal last year before I worked at The Drive.)

According to the user, he planned to put it into a 1936 Ford Coupe, also known as a five-window coupe. For one reason or another, that didn't happen. After a bit of time passed, the engine was sold to an experienced Nailhead builder out of the midwest named Jerry Wright. The current owner, Eric Godtland, purchased the rebuilt and refreshed engine from Wright. After reading my story, he contacted me and provided many of the details you're reading now.

The Project

The phrase "I know what I have" is a classic among boastful car enthusiasts, but in Godtland's case, he really does know. Godtland shared a letter with us that was given to its first owner by the Minnesota Air National Guard Museum, proving the motor's authenticity. 

Eric Godtland

He also shared with us the receipt from the engine builder, Wright. Apparently, this was the last engine the elderly Wright worked on before retiring. It was bored thirty thousandths over, received a slew of new bearings for the cam crank and rods, new gears in the oil pump, new pistons, and a variety of other top-end upgrades like a new Carter AFB carburetor and an updated ignition system. Wright also threw in a set of cast aluminum finned valve covers to replace the old pressed steel ones, an eye-pleasing update.

As mentioned, the previous owner wanted to put the engine in a '36 Ford Coupe, but that never happened (thankfully, if you ask me). In my original article on Hooniverse, I suggested that a 1965 Buick Riviera GS might be more appropriate. Speaking to Godtland, however, he disagreed.

Godtland was considering purchasing a 1963 Buick Wildcat convertible, but it was in rough shape. The engine in the car was not original to the chassis, and spending money on an old Wildcat that needed a full restoration—without a numbers matching engine—was a turn-off to him. When he stumbled upon the start-cart 425 built by Wright, however, he knew it was the perfect engine for the project, and not just because of its provenance.

Eric Godtland

The Nailhead was built in 1963, which makes it especially rare. Very few cars rolled off the line in 1963 equipped with the 425, at which point the engine was still mated to the old Dynaflow automatic transmission. "In 1963, only at the very end of the year, did they make 425s for any of the cars.... only about 30 cars apparently came with the 425 engine," Godtland said. 

So this is a rare engine even before its AG-330 roots enter the picture. If he brought together this Wildcat and this Dynaflow-equipped 425, he wouldn't be doing an engine swap just for the sake of an engine swap. It would make the restoration even more interesting.

With that in mind, he purchased the Wildcat and the Nailhead engine. Work is currently moving forward to restore the car to a condition worthy of one of the coolest Buick V8s out there. Talk about a conversation piece.

Cranking Over a Blackbird

Beyond wanting to know about the project car Godtland was putting this motor in, I also wanted to know what it was like to start the fastest jet ever with two screaming Buick V8s. Really, the best person to talk to would be a Blackbird crew chief. 

"The J58 used a chemical called triethyl borane (TEB) for starting and to light the afterburner. It is a highly volatile liquid that ignites when it contacts air," Greg Edmondson, a Blackbird crew chief told us. "If everything was working right, the 425s would start the J58 no problem." 

Edmonson was in charge of an SR-71 ground crew at Beale Air Force Base from Oct. 1982 through Dec. 1987. As well as working on the Blackbird, he was crew chief for two other aircraft, the F-4 Phantom II and the A-10 Thunderbolt II. He's a Buick guy, and was so before beginning his tenure with the SR-71. 


"The carts were very loud. The outboard pipes were about a foot long, The inboard wrapped around the bottom of the engines and exited below the outer pipes. You could easily hear the 425s over the J58s. Double hearing protection was worn at all times."

Despite their bone-rattling soundtrack—a video of which is embedded below—Edmonson is clearly very fond of the 425-powered AG330s. He's decidedly less enthusiastic about later carts which, due to reasons we'll discuss, had two Big Block 454s from Chevy. They were babied a bit more than the Buicks.

"I never knew exactly what modifications were done to the 454s, but according to the AGE (Aerospace Ground Equipment) guys, it was a lot. The 454s got a reputation for being fragile because of the way the different carts were handled. The Buick's were brought to the airplane cold or the crew chiefs would pull them from the ready line ourselves. The Chevy's however would be brought out to the airplane by AGE running and fully warmed up," Edmonson said. 

He went onto say that the 425s would often only get a few minutes to gain some temperature—SR-71s were typically in a hurry, believe it or not—but despite this they would pull all the way to redline consistently and normally without issue. It wasn't that way every time, though. He states he was "involved in the deaths of several 425s."

"During a late night/early morning launch during an Operational Readiness Inspection, we were starting the right-hand engine of the SR. I was at the controls of the cart. Right on cue, the left 425 started missing real bad just as we got the TEB shot, so we had to continue the start." If you're a Nailhead fan, you might want to skip the last part of this paragraph. "With one engine sick I had to rev the snot out of the Buicks, so much so that the wounded left engine deposited some of its internals on the floor of the shelter. Parts of 2 connecting rods and some piston fragments were waiting for us after the launch was complete."


Since the two engines were mated together with a belt, it wasn't the end of the world if one was running rough. It was a much bigger problem if the SR-71s weren't ready for their missions, however. If it meant killing a 425 so the Blackbird could snap the right photos, it was a sacrifice the ground crews had to make.

Later carts were equipped with 454s not because they were deemed superior, but because Buick ended production of the 425 back in 1966. This created problems with finding parts to repair stricken engines, but having a fondness for 425s—and indeed the Buick brand—Edmonson would go the extra mile to try and keep the engines going.

"Myself and a couple of my Buick buddies frequented the local wrecking yards, and would let the AGE guys know of any 401/425s we came across," he told us. "I never knew if they actually stripped parts from the local yards, but I was led to believe they did."

So yes, the fastest air-breathing jets ever built were kept aloft in part by straight-piped Buick 425s, some of them likely rocking junkyard parts. Simpler times.


Today, Edmonson is still a Buick enthusiast—actually, that's sort of selling him short. Not only does he still have his first car, a 1970 Buick Gran Sport Stage 1, but he also owns a number of other vehicles built by the automaker. "Several stablemates," as he describes them.

"A '70 Wildcat, two '70 Estate Wagons, three '70 GS coupes, a '70 GS convertible, a '70 GSX and my daily driver a '86 LeSabre Grand National."

The Coolest Buick Out There

Some of Edmonson's other stories will have to hold you off in the meantime, because the start-cart Buick project has yet to be completed. When it is, though, we'll be certain to have pictures of the build for everyone to see. The car's current engine needs to be removed, the interior needs work, and obviously the paint, convertible top and trim are going to need to be addressed as well. 

Godtland says it will be repainted in a metallic brown color; Bronze Mist. He also plans to install a saddle brown interior. Combine that with some nice weather, a 425 Nailhead with one heck of a story, and the top down? I'm not sure there will be a cooler Buick anywhere. 

Eric Godtland

Godtland told me he's glad the project is coming together, saying that it seems silly he ever considered not buying the Wildcat after getting his hands on the incredible engine that's going to power it. And the cost of all of this interesting history? Well, that may surprise you as well.

"The price of the motor and the price of the car were actually both pretty low," Godtland told me. "But the combination of the two, you know the universe opened up, and quite clearly was screaming at me: 'You should do this!' Right?"

Absolutely right. I can't wait to see it finished.

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