This stock-looking MGB hides modern Honda power

Photography by John Webber unless otherwise credited

British car enthusiast Zach Merrill loves projects–as long as they are devilishly complex and take years to complete. He’s well known in LBC circles for his brilliant, resto-modded Morris Minor Traveller inspired by a Morris dashboard he created as a kid in a woodworking class; he hung onto that prize for 20 years before he installed it into his reimagined Traveller. 

And while he was at it, he powered the tiny wagon with a Toyota twin-cam 4A-GE engine and drivetrain, and added all manner of modern bells and whistles. His creation turned out to be marvelous to admire and drive. It was showcased at the SEMA Show, ran a couple of Hot Rod Power Tours, and won awards and acclaim at events all over the country. You’ll find the Grassroots Motorsports feature (from December 2009) on this wooden wonder archived online. 

[A JDM-Powered Morris Minor?]

This inveterate builder–who was raised in his dad’s junkyard, started driving when he was 8, and by 16 owned three motorcycles, two cars and a dune buggy–has finished another epic build. This time he’s somehow finessed a Honda S2000 engine and drivetrain into a 1966 MGB GT, and he’s finished this installation to such a high degree of excellence and complexity that you’d swear it rolled out of a high-end custom shop.

Not so. Zach imagined and engineered and hand-crafted this machine in his cluttered, old-school garage in Greenville, South Carolina, where he labors without the benefits of a shop stuffed with gee-whiz devices. No CAD or CNC machines here. He used mostly “heat and hammers,” as he puts it, along with an innate ability to translate, fabricate and package a mechanical vision into reality.

Obsessed With an Engine

This time, Zach can’t blame a dashboard, but he does admit the build may have been boosted by his “project-fixation illness”–or what his wife, Libby, might call “obsession.” 

No doubt those quirks contributed, but the primary driver (pun intended) of this eight-year odyssey was an engine. “After Honda’s S2000 was introduced,” Zach explains, “I learned that its compact, high-revving F20C engine produced more horsepower per liter than any other naturally aspirated, mass-produced engine.” 

To builder Zach Merrill, classic black paint showcases pristine bodywork and sets off the red leather interior. During a weeklong, 1400-mile jaunt, Zach reports that the a/c keeps the interior cool.

Naturally, he had to have one of these 2.0-liter, 240-horsepower engines, recognizing it as a potent powerplant for another vintage LBC transplant. But as he searched, he learned this package was both elusive and expensive, and Zach builds on a budget. 

After running down several fruitless leads, he spotted a low-mileage example on Craigslist, along with its six-speed transmission. After looking at photos, he took an uncharacteristic flyer and was delighted when his prize arrived in as-advertised condition. At the time, he had no idea what sporty little car this drivetrain might power. So it took up valuable space in his garage for the next three years while family, job and other projects filled his life. 

Searching for a Transplant Candidate

As time passed, Zach reflected on his Honda-powered vision, evaluating transplant candidates. He’s always admired Rootes Group cars: “forgotten and cool,” he calls them. 

He considered a Sunbeam Talbot and a Singer Gazelle, but one got away and the other presented potential challenges in accepting the S2000’s deep oil sump. As he researched, he thought perhaps fitting a Sunbeam Tiger’s front crossmember in a Gazelle might accommodate the Honda engine. 

Zach looked for that needed crossmember and discovered instead a complete, basket-case Tiger. His project-fixation illness took command, and he bought it. Then he spent two years restoring the Tiger to a high degree–only to part with the car to fund his engine-still-looking-for-a-home Honda project. 

In 2012, a friend mentioned that he had a needy, steel-dash MGB GT stored in his basement. “That happened to be my favorite of the MGB production run,” Zach notes. “The car was totally knackered but not rusty, and I reasoned that the unibody would handle the extra forces this conversion would subject it to. GTs offer good weather protection and usable interior space, and replacement parts are readily available.” 

Looking back, he concedes that his reasoning may have been flawed: “My mental justification ability is quite agile, but sometimes self-deceptive.” Translation: He bought the MG because he liked it, not fully knowing the trouble he’d face in installing the Honda driveline. 

MG, Meet Honda

Once the GT was his, Zach started haunting websites and junkyards, looking for MG and Honda bits he might use. As he did, he talked to a friend with a paint and body shop who was experiencing a slow spell and said he would be happy to complete the GT’s bodywork and paint. 

But once underway, progress turned glacial. It was a year later when Zach finally rolled the MG’s painted body shell–sans fenders, doors and several other pieces–into his garage. But that delay worked out, because he filled it with months of planning, measuring, cutting, fabricating and welding.

How did the Honda drivetrain line up? “Let’s just say it wasn’t even close,” Zach admits. “While it may not have been as bad as, say, trying to fit an Allison engine into an Isetta, it was worse than I had anticipated.” 

In terms of size, the engine barely squeezed between the fenders. To accommodate this bulk, he had to reshape the left frame rail, open up the bell housing area, and perform major surgery on the MG’s transmission tunnel to fit the Honda’s taller, more robust six-speed, including moving the shifter opening aft.

Photography Credit: Zach Merril

Installing the Honda engine wasn’t a bolt-in proposition. An obscure vintage Koolaire (a long-gone a/c manufacturer) logo graces the vent plate, and a period Radiomobile (U.K. radio maker) badge hides a Bluetooth-equipped stereo system. The six-speed shifter looks like it was born there.

Drawing on a lifetime of experience, Zach built with no plans, just an evolving mental image. He conceived and fabricated every crossmember, mount, interface and subsystem from scratch, mocking up assemblies and tacking them together, fitting, refitting and modifying. He built heat exchangers, headers and an exhaust, an a/c system, fuel delivery, engine management, air intake and filtration, a cooling system, clutch and brake systems, and suspension. 

Under the hood, these components not only had to function, but they had to conform to Zach’s vision of what looked appropriate for a 1966 MGB. “I wanted to give it a Speedwell Performance Conversion theme,” he says, “or at least make an attempt to have it look like there was such a thing. BMC built some Special Tuning cars in their Works Group, and I wanted a car along those lines.”

Honda, Speak to MG

While maneuvering the drivetrain into position and securing it proved to be formidable challenges, persuading the Honda’s VTEC variable valve control and its ancillaries to converse with a 50-plus-year-old MG was equally difficult. 

“Since I didn’t have a complete donor car, I had to find the bits to make it work,” Zach says. He joined S2Ki, the S2000 forum, and started reading posts. He also bought an S2000 service manual and took a deep dive into its engine management section. 

He faced dozens of challenges. Here’s one example: Since his vintage MG key wouldn’t have an anti-theft chip, he needed to defeat that function in the Honda’s ECU, along with a few others not needed in his conversion.

He researched reflashing but learned that the ECUs tied to his Honda engine cannot be reprogrammed to change functions. He could have opted, as some racers do, to install a programmable ECU, but he wanted to retain Honda’s factory programming for his stock engine, along with its check-engine function for OBD II scanning. 

“I like my Honda ECU,” he says. “It makes for a well-behaved engine with good levels of drivability and economy.” So with help from computer whiz Caleb Holloway at Izze Racing, Zach used what Radio Shack (remember those?) called an experimenter box. It now houses two tiny circuit boards and a tunable resistor bridge, each piggy-backed with the ECU to control engine management.  

Photograph Courtesy Linda and Randy Sellet

Overall, Zach estimates he spent “hundreds of hours” designing and routing circuits, fabricating harnesses (from portions of two Honda engine harnesses and three MG harnesses), devising and building circuit protection, and testing and retesting. 

Consider this: This car’s fuse count went from two to 26, and the relay count from zero to 12. He wanted all those components hidden. Packaging under the dash, he tells us, proved to be a far bigger challenge than under the hood, not to mention harder on the back.

The bespoke work continues beneath the sheet metal, as the front suspension features a custom crossmember. The rear is suspended by a five-link setup.

During the long build process, wear and tear on his body caught up with him. He underwent back surgery, hernia surgery and eye surgery, gained two new knees, had a kidney stone procedure, and endured Achilles tendon surgery–twice. For months, he was reduced to shoving himself around the garage on a rolling stool, pushing off with a boot on his left foot. 

Despite all this, he never lost his determination to finish his project or his sense of humor. For him, the finished product made all the agony worthwhile. It exceeded his high expectations. “Somehow, as a total package,” he says, “it seems greater than the sum of its parts. I like this little car a lot!”

Public Unveiling

The Southeast British Car Festival in Dillard, Georgia, was the GT’s first outing, where it prompted some head scratching–well, it looks stock–regarding classification. Officials, despite Zach’s pointing out the obvious, put the car in the stock class. That didn’t last long. 

After several complaints, they moved the GT to British Modified, where it won first place. Like any modified MG, this Honda-powered creation elicits a lot of conversation among the faithful. Overheard comments ranged from “That’s just wrong!” from the staunchest purists to “It’s the coolest car here” from the more tolerant. Regardless of enthusiasts’ positions on the stock-versus-altered spectrum, Zach says he got a lot of compliments on the car and his workmanship–plus several inquiries as to whether it was for sale. 

“Most everything I heard at the show was overwhelmingly positive,” Zach recalls, “and several owners told me the GT got their vote for best in show. One of my favorite overheard comments: ‘Everything about the car looks like it was done on purpose.’” 

The black knob under the oil pressure warning light activates cruise control; the green button sets cruise speed and steps it down; the yellow button resumes cruise and increases speed. Photograph Courtesy Linda and Randy Sellet

Marque expert Glenn Lenhard, owner of Glenn’s MG & British Car Repair in St. Petersburg, Florida, spent time with the GT and came away amazed with the level of finish and detail, including the sly way Zach integrated his obscure Speedwell Performance theme under the bonnet. 

“There are just so many things to catch your attention,” Glen tells us, “like the Jaguar Series 3 XJ6 air filter assembly with matching air intake pipe and Lucas Injection sticker, plus Lucas stickers on the Honda engine harness and injection components. You’ll find a Bluecol antifreeze sticker on the radiator, Girling stickers on the brake system, and an original-style MGA cap on the brake master cylinder. 

“Many hoses are held in place with period-correct brass metal band clamps–no plastic wire ties in sight. I found something new every time I looked, and the best part is that all of that work is exactly the way the MG factory might have done it. Or better!”

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More like this
ZachMerrill New Reader
9/6/21 6:54 a.m.

A big "Thank you" to both John Webber and  Classic Motorsports Magazine for producing this feature article!

wspohn SuperDork
9/6/21 11:08 a.m.

Nice conversion.

These engines have been transplanted into Morgans and a particularly nice conversion on an MGA as well. 


I wanted to use that engine in my Jamaican bodied MGA, but back in 2007 when I looked for an S2000 engine, none were available so I used a GM V6 instead. Still wish I'd had an available S2000 engine.......

Sine_Qua_Non SuperDork
9/6/21 2:16 p.m.

I am hoping to put one in my Volvo 1800S in the near future but crikey has anyone seen the insane prices for Honda S2000's lately? If it continues upwards on this path, it will likely never happen. frown

Datsun310Guy MegaDork
9/6/21 2:55 p.m.
Sine_Qua_Non said:

......but crikey has anyone seen the insane prices for anything car related lately? If it continues upwards on this path, it will likely never happen. frown


joeymec New Reader
7/3/22 11:44 a.m.

My first car 50 years ago....A Tan converted to jet black MGB-GT!   What I really like about this example is that it looks totally original even down to the Smiths gauges and yet it is a rocket ship and.....reliable..... nice Job....  Still one of the prettiest coupes ever made............

theonlyiceman53 New Reader
7/4/22 7:28 a.m.

Absolutely a beautiful car!  I can see where it would be placed in the stock class as it looks like it was built by MG.  The valve cover seals it for me!  Great job.  I looked at using that engine on my latest project but because of the price, I used a 1UZ instead.  It's a long way from finished and it will not look like it was created at Abington although I can see the attraction of building that way.  

wspohn SuperDork
7/4/22 12:24 p.m.
theonlyiceman53 said:

  The valve cover seals it for me!  

I did something similar on a GM V6 swap I did on an MG.  Had a friend at a local technical college do a 3D scan of a factory MGA Twin Cam cover with engraved emblem and them modified it to suit the different curvature of the GM upper plenum and used a computer operated milling machine to cut it on the GM plenum.  Painted it MG red and it looks right. 





joeymec New Reader
5/20/23 12:22 p.m.

 Almost a year later and I am commenting again.   Zach, you are a true craftsman and I like your style.  In the past year, I acquired a New Hampshire barn find 69 BGT virtually rust free and am bringing it back to the vintage 66 look.  Sorry, s2000 powering is beyond me.  I will leave that to you.  Just love this project!!!  Best!!!

ZachMerrill New Reader
5/20/23 1:58 p.m.

In reply to joeymec :

Thank you for the kind words! The car is continuing to deliver stellar service and big fun. A month ago, Libby and I made an 1100 mile round trip drive in the car to sunny Florida to participate in the MG "Gathering of the Faithful".  Even though the car is decidedly non-stock, it was still openly embraced by all but the most unyielding of the MG purists. MG enthusiasts are good that way... Building and using the car has been a very rewarding endeavor. I hope you have a similar experience with your BGT!  Zach


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