SKU: 24589925900

King Engine Bearings Main Bearing Set (MB5721XP)

Sale price$81.67 Regular price$90.75
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Description

King Engine Bearings Main Bearing Set (MB5721XP)Todays sport compact race engines make more power than ever before. Yesterdays engine bearings load capacity no longer works for todays sport compact race engines. Tomorrows engines will be even more powerful. King bearings meet these demands with higher performance benchmarks, advanced materials and unique geometrical features. King Racings SV, GPC, XP, and XPC series of rod and main bearings were developed to meet these challenges through

Today’s sport compact race engines make more power than ever before. Yesterday’s engine bearings’ load capacity no longer works for today’s sport compact race engines. Tomorrow’s engines will be even more powerful.

King bearings meet these demands with higher performance benchmarks, advanced materials and unique geometrical features.
King Racing’s SV, GPC, XP, and XPC series of rod and main bearings were developed to meet these challenges through technologically advanced geometrical features and a unique metal structures. Together, they drive the industry to a higher level of durability, performance and expectation.

pMax Black is a unique tri-metal structure the has been developed to meet the ongoing demand for bearings with increased load capacity. As engines evolve and gain more power, engine bearings have to be able to handle the extra loading.

pMax Black consists of three layers that come together to form the strongest tri-metal bearing in the industry with load capacity exceeding the competition by as much as 24%. King Racing’s new hardening technology modifies the overlay molecular structure and creates a fatigue resisting shield.

The intermediate layer of a typical race bearing contains 2-3% tin, with hardness values of 90-95 HV. For a superior pMax Black intermediate layer, we increased the tin content to 4.5%, making it 22% harder (115 HV), with a load carrying capacity of 17,000 psi.

The overlay of a typical high performance bearing consists of a leaded alloy that contains 2-3% copper. It achieves a hardness level of 11 – 14 HV, and a maximum load capacity of 8,000-8,500 psi. King’s pMaxBlack overlay is significantly stronger than conventional overlays due to its 5% copper content and an innovative nano-scaled hardening process.

The pMaxBlack overlay contains 5% copper. It is further strengthened by a proprietary nano-scaled hardening process that modifies the molecular structure and creates a black fatigue-resistant shield. The outcome is a significant 29% increase in overlay hardness (18.1HV) and overall 24% increase in load capacity (10,200 psi).

SecureBond – Maximum tri-metal structural integrity

High loads and high RPM’s create critical stresses that travel through the multi-layer construction of a tri-metal race bearing. SecureBond is a micro-etch surface preparation process that strengthens the tri-metal structural integrity. SecureBond reduces the likelihood of catastrophic failure due to delamination of one layer from the other under extreme load conditions or metal–to-metal contact.

 



Check your bearing size using our fitment calculator here
Shipping Notes
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Exchange/Return Notes
  • We offer a 30-day return/exchange service after receiving.
  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
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SKU: 24589925900

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Mads
Battle Creek, US
★★★★★ 4
Its Great! Except one tiny detail
Style: Wi-Fi, Size: 512GB, Color: Pink, Configuration: Without AppleCare+, Style: Wi-Fi, Size: 512GB, Color: Pink, Configuration: Without AppleCare+
Ipad works great, easy to set up and everything transferred from the cloud from a backup I had (thank god because my other ipad is completely dead). Everything is in order except they put the magnets in the wrong spot xD. It doesnt matter functionality wise and I feel its more hassle to exchange than its worth so I am going to keep the iPad. With the case its in it doesnt really matter because theres a spot already for the pen. 4/5 stars
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Reviewed in the United States on May 13, 2026
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Riz
Omaha, US
★★★★★ 5
Great iPad
Style: Wi-Fi, Size: 128GB, Color: Blue, Configuration: Without AppleCare+
Great iPad, so much faster and stable than our old one (5th generation). Totally worth the price to upgrade.
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Reviewed in the United States on June 4, 2026
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Amazon Customer
Phoenix, US
★★★★★ 5
Overall a Great Item!
Color: Y-starry Night, Color: Y-starry Night
This case is very nice and feels sturdy. The color is accurate to the photos, and the print layout looks great. It includes a side pocket that can hold some paperwork, and the material feels durable. The magnetic closure works well and closes securely. I’m not completely sure about the strap yet, but there is a designated spot for the pencil, which snaps in well and stays secure. Overall, the cover fits nicely and provides very good protection for the tablet.
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Reviewed in the United States on December 31, 2025
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laura dunman
Boise, US
★★★★★ 5
Functional and great protection!
Color: Light Purple
Very nice case. Love the color. Case is exactly what I was looking for, it protects the iPad all around, corners and sides aren’t exposed. Pencil case is very convenient. Magnetic flip closure secures the case. It is a little heavier but that’s to be expected with it being PU leather and having a magnetic lock. I like the stand with different viewing angles as opposed to a case with a small trifold stand. Outside pocket is good for keeping papers you need to reference while working. Very compatible with my lifestyle. Great case for the money.
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Reviewed in the United States on June 11, 2026
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Professor
Boise, US
★★★★★ 5
I love the design of this iPad case!
Color: 1-Black
This iPad case is one of the best purchases I have made in a long time! I love the design and the quality of this product. It has the feel of genuine leather and the stitching around the edges is very tight with no loose threads. A magnetic flap holds the iPad cover firmly closed when not in use, and at the same time can hold the cover open when the front cover is folded back behind the iPad case. An elastic strap on the inside front cover aids in holding the device with one hand when the front cover is folded back. It doesn't matter whether you are left-handed or right-handed; it will work either way. Just turn the iPad upside down if you want to hold it in your right hand with your hand through the elastic strap. The power button at the top of the iPad is easily accessible through a precisely positioned slot in the TPU back shell, as is access to the USB-C port at the bottom of the iPad. There are also holes in the top and bottom of the TPU back shell for the speakers. The two volume buttons on the right side of the TPU back shell interact well with the volume buttons on the iPad itself. There is also a place on the right side of the TPU back shell to securely hold a Pencil 1st Generation (Apple or non-Apple brand), and it is easy to remove when needed. A pocket in the cover is a perfect place to put a small microfiber cloth so that you can periodically clean the glass of your iPad. This iPad case is going to last a long time!
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Reviewed in the United States on July 29, 2025

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