Performance & Track

Miata racing. Pretty much the two greatest words ever. We love racing Miatas, and we love building Miatas to race! From engines to tires, we are all in. We currently build and support engines for all types of track enthusiasts. Our in-house capabilities include TIG welding and fab, roll cages, custom powertrain setups, suspension and alignments, fender rolling and flare install, vinyl graphics/numbers, and more. We have everything needed to take a bone-stock car all the way to a race-winning trim, all under one roof. Need help pouring over the rulebook to see what mods your car should have? We are happy to join in the quest for victory with you and figure out what your car needs.

Leroy Engineering OEM and Boost ready Engine builds.

Whether you need a restored OEM engine to keep your car on the road, or a built and race ready track monster- we’ve got you covered!


For our OEM rebuilds

We use all Mazda parts to take your motor back to exactly how it left the factory… or better.

Each motor is disassembled, cleaned and inspected. The crank, block and head are measured to ensure they can be reused. The block gets bored and honed for the new pistons (up .25mm from the previous size) the deck is resurfaced, and then the block is painted OE black. The head is resurfaced, valve seats ground down (and replaced if needed). Crankshafts are polished and balanced. We replace the oil pump, water pump, bearings, gaskets, pistons and rings with Mazda OEM parts. All external pieces are painted or powder-coated to the customer’s choice of colors. Injectors are cleaned and/or replaced.

For our Forged builds

Everything gets upgraded! We rate our boost ready builds at 450 HP capable, but that’s only because we’ve not tested beyond that to find the actual HP limit. Built motors are more customizable than our OE builds, depending on your application. We design-in the correct compression ratio, clearances, and rates for the application. And we will walk through your installation to ensure it integrates with the rest of your system.

Our standard boost ready engine includes forged rods and pistons, ARP main studs, rod studs and head studs, billet oil pump and a Fluidampr balancer. Blocks are align-bored, resurfaced, bored and honed. Heads are decked to meet the target COMP ratio. Optionally, oil pans can be fitted with welded -AN drain fittings, upgraded dampers, valve springs, camshafts, timing gears, etc- depending on what the need calls for.

BP Engine pricing and definition

Short-block: Oil pan to block deck. Includes rotating assembly, oil pump, rear main seal, oil pan and water pump.

Long block: Oil pan to valve cover, a complete short-block plus rebuilt head, timing belt, valve cover – everything assembled, timed and ready top drop in.

Complete Engine: a long block, plus intake manifold, injectors, throttle body, plugs and wires, coil pack, temp sensors- a plug and play drop in.

Core: used engine that will be rebuilt. This includes all the pieces that will be restored and reused. If parts are missing, no problem! We can source them separately.

(Prices assume a buildable core is provided)

BP OEM street rebuilds

Short-block: $4,500

Long-block: $6,500

Complete engine: $8,500

BP Forged Boost ready engines (Off road only)

Short-block: $6,250

Long-block: $9,150

Complete engine: Call for quote

Ordering Process

First step is to shoot us an email, or give us a call. We want to learn all about your application and will put together a build sheet that meets your needs. Everything from fuel type, compression ratio, HP targets to colors and cosmetic options.

Next we’ll have you ship us your engine (if you are sending us a core). Ideally, we’d like to engine fully assembled. (this prevents loosing parts) We will then disassemble the motor, determine why it failed (if it did). We will then order the parts needed for the rebuild, and update your build sheet if needed.

Normally, we can have an engine turned around in about 3 weeks. With the current parts lead-time of the world, we are realizing closer to 5-8 weeks at present. We do not require any payment up front, we bill monthly. If you’re job stretches out into multiple months, you will receive an invoice at the end of each that can be paid online.

Engines can be picked up at our shop, or we can ship them to you. Freight for an engine is usually around $350.


List of performance services


  • Roll bar/Roll cage installation
  • Racing seat installation
  • Custom carpet and door cards
  • Steering wheels


  • Engine bay cleanup
  • Powder coating
  • Vinyl graphics (race livery, numbers, class)
  • Soft top replacement

Custom Fab

  • MIG and TIG welding
  • CNC machining
  • Exhaust work
  • Hood vents
  • Hitches


  • Coil-over install
  • race alignments
  • Fender rolling
  • Sway bars
  • De-powered steering racks
  • Brake work

Contact Leroy Engineering