Engine Rebuilding & Performance Builds
From a stock refresh to a full forged bottom end ready for boost — we build engines the way we'd build them for ourselves.
There comes a point in every build where the factory bottom end stops being the limiting factor and starts being the failure point. That's where engine rebuilding comes in. Whether you're refreshing a tired daily driver, prepping a platform for big boost, or stepping up to a dedicated race build, we handle every stage of the process — disassembly, measurement, machine work coordination, component selection, and clean assembly to documented spec.
We work on most common performance platforms: GM LS/LT, Ford Coyote/Modular, BMW N54/N55/S55/B58, Subaru EJ/FA, Honda K-series, Mitsubishi 4G63/4B11, Nissan VQ/VR/RB, and more. Every build gets a spec sheet — what's in it, what it's good for, and what it's not.
What's Included
Every engine rebuilding engagement at Rapid Racing covers these essentials.
Teardown & inspection
Full disassembly, photo-documented condition report, and root-cause analysis if the engine failed.
Machine work coordination
Honing, line-honing, decking, valve work, balancing — done by trusted local machine shops to your spec.
Forged internals
Forged pistons, H-beam or I-beam rods, balanced rotating assemblies — sized for your power target.
Bearing & clearance work
Measured bearing clearances, proper torque specs, and clean assembly in a controlled environment.
Head work
Valve job, springs, retainers, port matching, and head gasket selection paired to your boost/RPM goals.
Tune & break-in
We don't just build it — we put it on the dyno, break it in properly, and tune it for the long haul.
Street rebuild vs. race build
We scope every build around what the car actually does. A daily-driven, occasionally tracked build needs different rod selection, different ring packs, and different piston-to-wall clearance than a dedicated drag or road-race motor. We'll walk you through the trade-offs so you don't pay for race-build clearances on a street car (or try to street-drive a build that lives at WOT).
What it costs
Engine builds vary widely with platform and goals. A short-block refresh on a common 4-cylinder platform might come in around $4–7K in parts and labor; a fully-forged big-power V8 build with head work can run $12–20K+. We give itemized quotes — no mystery line items, no surprises.
Lead times
Machine work is the long pole. Expect 4–8 weeks for a typical build once parts are on site, longer for builds requiring custom components or hard-to-find OEM parts. We keep you updated through the whole process.
Common Questions
My engine knocks/burns oil/has low compression — does it need a rebuild?
Maybe. We start with diagnostics — leakdown, compression, oil pressure, and a borescope inspection — so we know what's actually wrong before recommending a build. Sometimes the answer is rebuild; sometimes it's a cheaper repair.
How much power can a built engine hold?
Depends on the platform and the build. A properly forged 2JZ can hold 1000+whp. A built K20 can live at 600+whp. A built LS short-block with the right heads can take 1500+whp. We'll set realistic targets based on YOUR platform and budget — and we won't sell you more build than your goals require.
Do you do block / head machine work in-house?
Some — primarily assembly-side work. For honing, line-boring, valve jobs, and balancing we use trusted local machine shops we've worked with for years. You get specialist quality without the runaround.
Can I supply my own parts?
In most cases yes, though we may push back on parts we don't trust for your application. Build quality is our reputation — if a part is going to come apart, we'd rather you not run it.
How long does a rebuild take?
Plan on 4–8 weeks from "parts on site" to "car on the road" for a typical build. Race builds with custom components run longer. We update you weekly.
Ready to Get Started?
Book your engine rebuilding appointment online or call us to talk through your build.