If you’ve got the time, space and patience to try building, or rebuilding, an engine for your project car, you could save a bundle of money versus getting shop to do all the work. Well, that’s the theory. But as this video shows, you can still land yourself with a big bill.

YouTube channel IG Designs recently documented the process of building a Honda K24 engine for his Mk3 Toyota MR2 in a series of standalone videos. But the latest video crams the entire build into just eight minutes, and breaks the costs down for the individual parts and procedures along the way.

The 2000-2007 ZZW30 MR2 was a great handling car, but it wasn’t exactly over endowed in the engine department. The only engine available was a naturally aspirated 1.8-liter 1ZZ with variable valve timing that made 138 hp (140 PS) and 126 lb-ft (172 Nm) of torque. IG Designs’ earlier videos show how he previously swapped that for the short-stroke 180 hp (182 PS) 2ZZ that came with variable valve lift in addition to variable valve timing, and was fitted to the Celica. But for the MR2’s next upgrade, the YouTuber jumped ship to Honda.

Starting with a 2.0-liter K20A2 screamer, as fitted to the early 2000s Acura RSX, and a torquier 2.4 liter K24A4 engine, the kind you’d get in a Honda Accord from the same period, the idea is to build one great K motor that will give the unsuspecting MR2 almost twice the power it had when it left the factory.

Related: This Toyota MR2 Has A Supercharged Audi V8 Under The Hood

Those two used engines cost $200 and $300 respectively, but factor in some machine work to deck the cylinder head, install the valve guides and balance and polish the crank, and the bill is up to $2,117 before IG Designs has even really got started.

And the costs rise steadily from there. You’ve got your obvious expenses like new pistons ($512) and rings, but there are additional hidden expenses for the first-time builder, like a machine to gap the rings ($45) and ring compressor ($13), plus unsexy costs like $300 for a new timing chain and guides, and $180 for the tensioner. Not big money, maybe, but it all adds up.

And it really does do it quickly in this case. Having added $360 for an intake manifold, $375 for an oil pan, $449 for a clutch, $1,250 for a matching Honda gearbox and diff, then over $700 for a fuel rail and injectors, both IG’s credit card and his torque wrench are in desperate need of a vacation. Throw in the $451 for the conrods, a figure he forgot to add to the tally before uploading the video, the costs comes to $12,012.83, which must make the engine worth twice as much as the car.

But there’s a real sense of pride that comes from building your own motor, you always learn something along the way, and we’d love to give that 200+ hp MR2 a shakedown run.