Frequently Asked Questions

Does it matter which way I place a Boundary gear inside the pump housing?

Most oil pump gears are symmetrical, and it doesn’t matter which way you install them. There are a couple of exceptions:

  • Vane Ported or “Black Series” Gears always have their porting facing the pump cover. That is the cover that sandwiches the pump gears in the housing.
  • Other gears that have an orientation will be gears that have reliefs on the crank lands. If the gear has a relief in the center, that relief always faces the block.

What does Boundary do to the oil pump assemblies?

The process will start with a complete de-burr inside the pump. Each housing then receives a stoning to remove high spots on the sealing faces and thorough cleaning. Every component gets a check on form fit and function. From here, we create a quality record stating all the critical clearances in the assembly and package a copy of the blueprinting with the product.

Now that function is guaranteed, we lubricate all the components inside the assembly, minimizing priming time and wear. Then we apply any sealants, Teflon, or thread locker required and torque any fasteners to specification.

What are the benefits of Black Series gears?

The “Black Series” gears come with a patented Vane Ported design. This porting helps the engine survive beyond 7,000 RPM by increasing the maximum oil flow the pump can produce at high RPM. These gears are also specially treated with MartenWear and will never break down or wear with this treatment. The MartenWear treatment underwent testing to 15,000 RPM without any wear, ensuring full pressure at even F1 levels of abuse.

Do I need the CM-OPG-MUSTANG or the CM-OPG-F150?

The CM-OPG-MUSTANG fits almost every Mustang from 2011-2021. The only exception being the GT500 mustang starting 2008-2014 and the GT500s starting in 2020.

The fitment for the F150 is a little more complicated due to the changes in gears over the years. Here is what you need to know:

2015-2017 F150 truck has the same gearset as the Mustang (CM-OPG-MUSTANG)

2011-2014 F150 truck used a special gear set (CM-OPG-F150)

2018+ F150 truck also uses the special gear set (CM-OPG-F150)

When using the F150 gear set, you have been careful as they will fit into mustang housings but not produce any flow or pressure.

What is the difference between the BP-S1 and the BP-S2?

BP-S1 contains a non-VVT gear set inside the housing. This oil pump assembly would work well if you are running standard engine clearances and planning to run under 8,000RPM. The BP-S1 comes standard with 0 shims which the customer can specify at no extra cost.

BP-S2 contains a unique high-flowing gear set. The BP-S2 pump is a better option when the engine receives larger bearing clearances and needs additional pressure to cope with large bearing loads. The BP-S2 comes standard with two shims which the customer can also specify for no extra cost.

How many shims do I need for the BP pump?

The number of shims needed depends on how much RPM and horsepower the bearings have to sustain. The engine will survive more abuse with more oil pressure, but the drag on the motor is higher as pressure and flow go up. Your engine builders plan should include a recommendation of what pressure the engine needs to survive at the intended level of performance. While we can provide basic recommendations in the chart below.

ShimsPSIPower
0 Shims 60 PSI 200 WHP or below
1 Shim66 PSI 250 WHP or below
2 Shims72 PSI 300 WHP or below
3 Shims78 PSI 350 WHP or below
4 Shims84 PSI 500 WHP or below assuming large main and rod clearances
5 Shims90 PSI 600 WHP or below assuming large main and rod clearances
Shim table for BP pumps