Remanufactured to exacting specifications

The core products our technicians work from are vital to the remanufacturing process. These products are the raw material from which the reman process begins.

But before you purchase a remanufactured engine from Gearhead Engines, that product completes the following strict, remanufacturing process.


“Close enough” doesn’t apply when we’re remanufacturing products. For example, engine configurations vary between vehicles, so identifying the right engine is crucial to ensure you purchase the correct solution. With our experienced staff and a comprehensive cataloging system, know that you’ll get the right product for your needs.


All of our products are carefully taken apart and cataloged for the machining process. Once dismantled, all reclaimed parts are tagged and kept as a group so they can be built back into the same finished assembly. This method of manufacturing ensures tight quality control, consistency, and a better finished product.

Removing 'wear' parts

Parts that wear over time like pistons, rings, gaskets, and bearings are always replaced with new.

Initial testing

Our skilled machinists thoroughly test reclaimed component pieces to ensure they can be brought up to new OE specifications or better. Testing includes wet magnaflux (magnetic inspection for tiny cracks), pressure testing, dimensional measuring, and preliminary testing of all surfaces.


Using the latest technology, cutting-edge machinery, and decades of engineering know-how, our teams take into account every available update and improvement to the original design.  Sometimes this means your product will be better than new.

These machining steps include:

  • 100% align honed — All block castings are align-honed, providing the best surface finish for optimum bearing life, heat transfer, oil clearance, and alignment of the rotating assembly.
  • 100% deck resurfacing — All engine blocks and cylinder heads are resurfaced, providing the strongest-possible head gasket seal. This machining is performed parallel to the crankshaft centerline, ensuring equal compression.
  • 100% cylinder reconditioning — All cylinders are bored 90 degrees to the crankshaft centerline. The cylinders are then plateau diamond-honed to achieve the proper cylinder size and surface finish, assuring optimal compression and oil control.
  • 100% cylinder head reconditioning — All valve guides are reconditioned to better-than-OE-specified tolerances. All cylinder head valve seats are three-angle machined for optimum sealing and flow. High-temp valve stem seals provide superior sealing and oil control. Valve stem heights and lash are measured to specification, ensuring optimum engine performance.
  • 100% crankshafts reground — All crankshafts are reground to better-than-OE tolerances for clearance. Crankshafts are ground on both stroke and index and are micro-polished to a glass-smooth surface finish.
  • 100% connecting rod reconditioning — All connecting rods are reconditioned to better-than-OE-specified tolerances. Connecting rods are machined perpendicular to the housing bore, providing true journal alignment and minimal bearing stress. All rods are diamond-honed to achieve proper size and surface finish.

After our precision machining process, the parts get a thorough, cleansing wash before assembly.


Each remanufactured engine is assembled according to our quality assurance system’s documented, detailed instructions. To ensure you only get the highest quality, our technicians use a large percentage of brand-new OE grade parts during our assembly process.

Final testing

Our complete engine assemblies are fully tested using simulated and/or live-run test stands. All critical engine parameters are checked at this step by highly-trained technicians, verifying correct timing, correct valve train setup, compression, oil pressure, oil flow, vibration, knocking or unusual noises, variable valve-timing actuation, and fluid leaks. Finally, our technicians pressurize the finished assembly to verify water jacket integrity.


Most of our engines are shipped in durable, returnable, high-impact-plastic shipping containers. These containers eliminate shipping damage and make core returns a breeze by providing a safe, easy way to return cores without spilling any residual liquids.