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Boundary Engineering upgraded oil pump

Boundary Engineering upgraded oil pump

Regular price $339.00 USD
Regular price Sale price $339.00 USD
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At high engine speeds or high power levels, your oil pump is subject to damaging vibrations coming through the crankshaft. The gears inside are made of sintered metal, which can withstand about 6 Ksi (6000 psi) of stress before they shatter. Then you lose your oil pressure and very shortly, your engine.

Boundary Engineering has developed 90 Ksi 4140 chromoly steel gears for the Miata oil pump. Yes, that's 15 times stronger than stock. No more shattered gears, no more blown engines!

Pumps are available in various stages. We recommend pairing them with an ATi damper for best protection of your expensive engine.

Stage 1 is a complete pump, assembled with the upgraded gears. They're built to the 1991.5-2000 size and volume using factory housings.

Stage 2 is a complete, high volume pump. The factory housing is machined to accept the deeper VVT gearset, providing high volume and increased oil pressure. The relief valve is also shimmed to raise the maximum oil pressure from 60 psi to 70 psi. This is our favorite option.

Stage 3 takes a Stage 2 pump and adds an upgraded relief valve. Stock valves can sometimes stick, which leads to a loss of oil pressure. The 3 has a hardened steel sleeve pressed in for the relief valve to ensure there's no chance of the valve sticking.

Note that if you have a 1990-91 short nose crank (four-slot front crank pulley and a VIN of 209446 or lower), the only option available is the Stage 2.

Please note that these pumps don't include a front seal so you can choose your own. You will need a new gasket for the oil pickup as well, but the O-ring to seal it to the block is included. These are usually included with engine rebuild kits, so check to see if you have one already. If not, you'll need to order one separately.


Instructions are not currently available.


Ships free in the US.

There are no shipping restrictions on this item.

What does it fit?

Fits: 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1999, 2000, 2001, 2002, 2003, 2004, 2004 MSM, 2005, 2005 MSM


Emissions do not apply.





Customer Reviews

Based on 4 reviews

Awesome sauce

Just Shy of Amazing

Overall, the Boundary Racing Pump is a solid purchase if you plan to make any "big power" mods for the stock block. I own a 2002 Mazda Miata with a 1.8 VVT motor. I bought the stage 2 SN and it's great...until you realize the seal that comes with the oil pump is utter garbage.

AFTER taking the entire front of the motor apart, tossing it back together, the front main seal began to leak. After some forum reading, I found out that the front main seal from Boundary is garbage. I suggest you replace it with an OEM right out the gate. Aside from that? Just as good as OEM, if not this is an OEM+ Product

good pump, bad ancillary components

nice pump, looks great on the bench... installs just like stock, but oh... don't forget to check the oil galley plug before you install... the pump comes with the wrong plug (admitted by Boundary themselves) and the plug usually fails to seal... go to Miataforum for more info on this... other than that... it's a great product... maybe they fixed this? I doubt it since it's been several years of complaints on the forum and my new pump still had the wrong plug

Great product!!

Pump was easy to install and works great with the new forged turbo build replacing the stock pump.