Boundary Engineering created the High Flow Billet Oil Pump Assemblies to address the issue of finding a high quality, high performance pump that’s ready to bolt on to the engine.

These pumps feature:

• CNC machined housings to increase pump size and flow

• Custom machined super strong 4340 billet oil pump gears for each housing

• Housing are fully de-burred to reduce turbulence and increase flow

• Outlet and inlet passages bored and precision honed to reduce turbulence and increase flow

• Blueprinting verification using signed and dated sheets stating your particular pumps clearances and processes.

• Cleaned with ultrasonic, air blast, and visual inspection triple clean technique

• Assembled with Teflon impregnated grease

• Sealed in air tight heavy mil bags to prevent foreign contamination

The MX-5’s oil pump gears are known to be a weak point in the motor. Every time the engine is brought up past its stock redline, or past its factory power level you are pushing a pump that was designed to the lowest denominator using powdered metal casting technology. This process of casting produces parts that are between 5%-10% the strength of 4340 billets. On top of that cast components tend to crack, not bend, so when the oil pump assembly does self destruct its likely to be a catastrophic and sudden failure that can ruin Carrillo rods, JE pistons, and high performance camshafts in a matter of seconds.

If you do take the risk of assembling your high performance engine with a powdered metal stock oil pump it still takes sophisticated measuring equipment to ensure the replacement pump you ordered is in specification for your housing. Measurements down to .0005 and surface rougness are both measured very accurately using the Boundary Engineering inspection process. The tools do this step alone are worth thousands, and with this purchase its already taken care of for you by highly qaulified machinists.

This product takes all the guess work out of assembling your motor. Purchase, bolt on, drive, and never worry that your engine’s next redline visit could send 8000 RPM components into a steel on steel grinding match.

Gaskets which you should check to make sure you have in the gasket kit you are using:

• Oil pickup gasket
• High Pressure Oil Pump Seal (o-ring)

Flow Increase

9% Flow Increase $389.10 22% Flow Increase $459.12

Oil Relief Spring Shimming

Stock Pressure ~60PSI 1 Shims (+7PSI) 2 Shims (+14PSI) 3 Shims (+21PSI) 4 Shims (+28PSI) 5 Shims (+35PSI)