Engine of the Week is presented by
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We were first introduced to Ramiro Ramirez last fall when he messaged us on Instagram to tell us about his shop and his engine work. Located in Monterrey, Nuevo Leon, Mexico, Ramiro’s shop, Fatboys Racing Engines, has been building high-performance engines for 16 years. Needless to say, we were impressed and wanted to know more.

Fatboys Racing Engines has a focus on naturally aspirated and nitrous engine builds, and has recently started to offer forced induction builds as well. The shop’s engine builds are most commonly used for street/strip, drag racing and sand drag applications.
As Ramiro has taken a deeper dive into forced induction builds, he reached out to us again to tell us about the details of a competition level, forced induction engine he was building for a Trans-Am WS6 chassis. The engine is a turbocharged 427 cid LSX, and because it’s forced induction, it’s a little bit different than the usual stuff Ramiro cranks out.

The build started with an LSX short-deck block with a 4.125˝ bore. The shop machined the block to accept ½-inch ARP head studs. Ramiro opted for a 4.000˝ stroke crank and 6.125˝ rods. He used ARP hardware, Clevite coated main and rod bearings, Wiseco pistons with heavy-duty piston pins, and Total Seal turbo racing rings.
The LSX build also got equipped with a Melling oil pump, Moroso oil pickup and oil pan, a solid roller camshaft from Steve Morris Engines, COMP Cams solid roller lifters, COMP Cams pushrods, T&D shaft-mount rocker arms, and Mast 305 Black Label heads with solid roller springs good for .800˝ lift.

Up top, the LSX engine got an LS7 CID intake 4500 plenum, a Wilson Manifolds 105mm 4500 billet elbow and a Wilson Manifolds Hi-Boost 105mm billet, dual-seal throttle body. For fuel, Ramiro used Atomizer racing injectors, and to put power to the wheels he used a Power Glide transmission and billet converter from FTI Performance.
Lastly, the LSX features a 94mm Garrett turbo and a water-to-air intercooler system that should help this engine build make somewhere between 1,500 horsepower and 1,800 horsepower.

Engine of the Week is sponsored by PennGrade Motor Oil, Elring – Das Original and Scat Crankshafts. If you have an engine you’d like to highlight in this series, please email Engine Builder Editor, Greg Jones at [email protected].