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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  • Except Preorder products are shipped in 48 hours.
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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]
  • Please click here for more details>>> Return & Exchange Policy
SKU: 24589925900

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4.8 ★★★★★
Based on 27 reviews
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R.
Lowell, US
★★★★★ 5
Great product
Color: Navy Blue
Awesome product. It does everything I need it to. Very smooth and stylish as well.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 12, 2026
K
Verified Purchase
Kindle Customer
New York, US
★★★★★ 4
keyboard and case is phenomenal, trackpad is borderline unfunctional
Color: Black
I bought this case, because of the keyboard and trackpad, i wanted to use my ipad more like a laptop. the keyboard is phenomenal and certaintly better than other cheap ipad keyboards i have tried, I can actually use this one without having to repeatedly slam or hard press certain keys and can actually have a flow of typing. additionally, everything else regarding the case itself is amazing. it isnt cumbersome or bulky and it is very easy to swap between ipad and laptop mode on the fly. the trackpad however is genuinely unusable. the sensitivity on the trackpad is horrid and I cannot figure out how to change it, and additionally, clicking using the trackpad is outright impossible. you try to left click, it registers as a right click, or you try to click and it instead snaps your cursor to the bottom of the screen instead. it is also impossible to use any gesture functions with the trackpad, even something as simple as scrolling up and down or left to right is impossible. it is outright impossible to have any kind of workflow using the trackpad. it is unfortunately just a lot easier to use the keyboard and touch screen! its a shame that the keyboard and case itself is very nice too, so I will now have to spend more money on a separate mouse, which is additionally ANOTHER item i will have to carry around, just to make what I already bought work the way I expected.
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Reviewed in the United States on June 4, 2026
J
Verified Purchase
Jessie A.
Houston, US
★★★★★ 5
Great quality at a great price range!
Color: Navy Blue
Works very well for the day to day. Great quality at a great price range. Would definitely buy again if needed.
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Reviewed in the United States on May 14, 2026
A
Verified Purchase
Allana W
Carnegie, US
★★★★★ 5
Solid case.
Color: Sky-Blue
Love this case. Fits great and the color is great! The keyboard is nice and it even has a little spot for a stylist.
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Reviewed in the United States on June 3, 2026
N
Verified Purchase
Nosiest
Battle Creek, US
★★★★★ 4
Cheap and good
Color: Black, Color: Black
I chose the color black and it gives a really nice look, especially with the multicolor led lights around the keys. It is very easy to clean and you can shut off the keyboard to prevent any mess with the iPad. The magnet is very nice and keeps the keyboard in place. The keyboard doesn’t easily slip or anything so it holds the iPad very well. Only bad thing is that over time the iPad begins to scrape off the pain and it leaves your keyboard with some white spots all over :/ but if looks isn’t something that you care about, this is the keyboard for you. Don’t use it for gaming because there is a delay in functionality when you press a key and then try to use the pad. Also, you have to press the keys a bit harder than the usual keyboard. But for the price? This is a great item! Definitely worth my money
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Reviewed in the United States on January 18, 2026

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