2.4L Engine Builder Kit "The Scalpel" The De-stroked Powerhouse

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This system by default includes the rotating assembly basics. Your Crankshaft, Connecting Rods, Forged Pistons. Configure the rest of your build using the menu system above. 

Use this page to properly order your Ford/Mazda L5-VE 2.5L engine conversion system. These components result in a robust 2.4L (2365cc) rotating assembly. Here you can choose which compression, bore and add on features you'd like, depending on your goals.

Why would I want to make my 2.5L a 2.4L?
If you've found yourself here and don't know why you'd want to "de-stroke" your beloved displacement away, we're glad you asked. The 2.5L gained it's popularity because it's a fairly drop-in and affordable way to beef up your powerband. Now that it's so prevalent, it's found it's way into turbo and supercharged builds, race cars and high output N/A configurations. The problem is fundamental with the engine though. In order for this 4 cylinder to achieve the massive 2.5L of displacement, the stroke was increased to 100mm! A 100mm stroke means your pistons are moving at an incredibly fast rate of speed. This means it's exponentially HARDER on your engine components when you go beyond the Ford Fusion 6300RPM redline. De-stroking that, along with several other improvements in the rotating assembly unlock a WAY more useful limiter, especially in a Miata. 

What are the results?
This conversion is the difference between a sub compact SUV (Ford Escape) engine and an actual race motor.  Forget 6300RPM and a powerband that falls on it's face before then. Wrap this setup out to 8000RPM with supporting head modifications and enjoy a table top torque curve while you're at it. On turbo or supercharged setups, don't stop at 300whp - this bottom end will support 500whp+ and more if you choose to sleeve the engine. 

Highlight features:

  • Forged Pistons - Our proven forged Duratec pistons that feature an enlarged 21mm tool steel wrist pin.
  • Forged Rods - Exclusive to Fab9, custom length H-Beam featuring ARP hardware. 
  • Forged Crankshaft - A balanced 2.3L crankshaft from Ford Performance. 
  • Billet Camshafts - Our in house camshafts that we've been shipping for years. Now manufactured as a full billet blank instead of a re-grind.
  • Harmonic Balancer - In collaboration with Fluidampr, Fab9 developed a proper 2.5L dynamic balancer. The 2.0L bonded balancer you removed for your swap is NOT up to the task. Keep your bearings happy and your RPM's high with this peace of mind.
  • Head Studs - Our Ultra Duty 2800 Stud System - Teflon coated, 280ksi+ 500whp proven. For you boosted folks, keep that cylinder head from the dreaded "head lift" that happens over 300+whp on these engines.
  • Keyed configuration includes a keyed crankshaft, keyed oil cog drive and a keyed Balancer if one was added. 


  • Ford Duratec 2.5L inline 4 cylinder
  • Mazda MZR 2.5L inline 4 cylinder

Compression Options: