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Napp Motorsports

Boundary Oil Pump - Miata

Boundary Oil Pump - Miata

Regular price $329.00 USD
Regular price Sale price $329.00 USD
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The Boundary BP oil pump starts with a fully torn down and inspected housing. This housing is then assembled with our billet oil pump gear and sealed. This pump also and comes with the option for a high flow billet backplate for those running over 7000 RPM consistently.

All assembled billet pumps undergo the following:

  • Pump is completely taken apart, all parts under go ultrasonic cleaning, air blast, and hand inspection.
  • Pump is hand de-burred.
  • Our industry leading mirror finished gear set is used
  • Stainless Torx heads replace the stock fasteners
  • All fasteners are torqued to spec
  • Loctite applied to fasteners to prevent back out or loosening
  • Anaerobic sealant applied to critical areas to boost pump up speed and reduce aeration.
  • Assembly lubricant applied to all critical surfaces to get oil flowing fast on startup
  • Parts are blue printed and issued with specification sheet.

Stage II pumps increase the overall flow by machining a deeper pocket into the oil pump and fitting larger gears in this pocket. This increases the strength of the pump, increases mid-range oil pressure, and increases the strength of the oil pump gears.

The Stage II Pumps have these additional modifications:

  • Larger gears are fitted into the oil pump which increases mid range protection and insures compatibility with VVT.
  • The pump is shimmed increasing maximum warm pressure from 60 PSI to 70 PSI.


  • BP-S1 (Stage 1) - 1991.5 - 2000 Miata (Long Nose Crank) - Not Recommended For VVT Engines
  • BP-S2 (Stage 2) - 1991.5 - 2005 Miata
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