This is a 1974 Ford Maverick with a 5 litre 302 cubic inch Windsor V8  running and driving on a single lawnmower carburettor. Why? Because people said it couldn’t be done.


Meet Luke, aka Thunderhead 289 – why’s he called that? It doesn’t matter. He gets a kick out of driving and maintaining cars others only deem fit for the crusher. He bought the Maverick on a whim inspired by its, rough as sandpaper and searing on the eyeball appearance . It was also cheap. Filthy dirty, get it outta here, no refunds, cheap. Luke suspected the fugly Ford was good for a little summer fun before it expired. The rotted out old Maverick just would not die. He beat it up and down the highway, put 30000 miles on the old V8, fiddled with it and tweaked it, and it just kept going. Luke loved it.

So. the lawnmower carburettor: The concept of sticking a tiny lawnmower carb on a V8 engine has rattled around forums for years. Luke posted an April fool of a lawnmower carb set up for his car. It caused a stir, just not as he anticipated…
‘It can’t be done, It wont climb hills, you’re talking shite, you’ll suck the float bowl dry,  it will kill the engine, you’re an idiot’

That’s the sanitised version. Surprised by the outpouring of social media bile, he was inspired to go and do it for real. He’s been tuning and experimenting, with carburettors for years, so with an engineering degree in his back pocket, and as he says, just enough knowledge of fluid dynamics to be dangerous, he did the decent thing, and went to his shed.

He wasn’t thinking of just slapping a lawnmower carburettor on there. He knew it needed a little tickling to be even a half viable option. He obtained a compatible lawnmower carb that used a float bowl. He ran a CAD session using Fusion 360 software then fired up his 3D printer to make adaptors to fit the carb to the V8. He added two horizontally opposed air filters and fabricated a mechanical throttle linkage. To stand a chance of operating, he advanced the timing and initially set the carb to run rich.

For the car to run effectively he needed to control the fuel air mixture to provide a flow to suit different driving scenarios. He used an off the shelf Arduino board- a microcontroller you can adapt for multiple uses, and modified it to offer dynamic settings for the air to fuel ratio. Using free software off the internet he created an app to link its operation to his mobile phone. He called it his carb cheater. Basically, it works via a valve to adjust the vacuum pull on the carburettor.

Once the timing was dialled in, the car fired up and idled smoothly. It ran faultlessly on a 60 mile test run, able to accelerate through the gears and reach and maintain highway speeds. In essence, the 5 litre V8 now performed like a motor with a tiddler engine, lacking horsepower but providing a welcome benefit. The Maverick usually managed 24MPG. It was now returning 40. Luke filmed the whole process,  posting it on YouTube, and the US automotive media picked it up. The naysayers remained unimpressed.
‘You’re talking shite, you;re faking it, The MPG was BS, do some real miles, you will kill the engine…..’

 Luke took The Ford on a 1000 mile jaunt, then stuck it on a Dyno. The V8 Maverick peaked at just 59HP. Then he drove it home. Job done. His tiny home made carb set up ran without incident, and in the middle of a $5 a gallon gas crisis in the US, enabled the ratty, decades old Maverick to return 41mpg (US not Imperial) on a V8 engine – to put that in perspective his 1970s five litre V8 was averaging  just a few MPG less than a new US market Toyota hybrid.

Luke has no plans to run the Maverick on the carb full time. He doesn’t advise it. After all, if your priority is fuel economy, buy a small economical car, not a V8. He only did it because the absurdity of the idea appealed to him. His success was in large part to his self designed, home built, carb cheater. It proved two things.
1) Yes, technically a V8 will run on a Lawnmower carb
2) Never underestimate the ingenuity of a bloke tinkering in his shed.

For the full story, see his engaging “lets just see what happens” video about the experiment here

About The Author

Steve Swanson

Steve turns any opportunity to write about cars into a roadtrip. It's seen him ride shotgun in a Bentley Blower with Clive Cussler, and cross paths with automotive YouTubers in Canada and the US. His work has been published in Magneto, Classic Cars, Classic American and some magazines that no MotorPunk reader has ever heard of. When he's not writing or driving you can find him kicking tyres at seedy auctions and hawking junk optimistically described as Automobilia

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