What is a Bi Metal engine bearing ?

Bearing consisting  of two layers bonded together and it is usually an aluminum alloy on steel. King Bi-metal bearings are AM, SI, and HP.


What is a Tri Metal engine bearing?

Bearing consisting of two layers bonded together with a plated overlay third layer. King Tri-metal bearings are CP and XP.


Does King have different undersizes available?

Yes, usually std’s thru 040’s.  The widest assortment in the industry.


What is the King undersize if I want to increase my clearance by .001”?



Can I mix a STDX and a STD or a STD and a .001 to get my desired clearance?

Yes, but do not mix a STDX and a .001


Does King have a ¾ groove main bearing?

Yes, but only in the HP Series.


Does King have oversize OD bearings?

Yes, on some applications.  Usually on the more popular ones including the new cracked rods.


Can I Scotch Brite King Bearings?

No.  You should never use any kind of abrasive pad on the bearing surface as this practice will reduce bearing life significantly and is harmful to the overlay.


Can I use plastigage to measure my oil clearance?

Yes, but using plastigage only gives you a close reading.  A more accurate method is to use a dial bore gage.


Is it safe to change the crush height of a bearing to decrease oil clearance?

No.  You should never alter the height of a bearing  as this might cause the bearing to spin in its bore.


Should I resize my rod and main housings before installing new bearings?

Yes.  The housing size and shape can be altered due to previous extended use.


If I am building a street/strip drag race motor, what King bearings is best suited for this kind of use?

The perfect King bearing for this application is HP because it will take high loads for short durations of time while offering superior embedability and conformability characteristics.


If I am building a circle track engine with lots of horsepower and torque, what King bearing is best suited for this kind of use?

The perfect King bearing for this application is XP because it has the capacity to sustain very highs for extended periods of time.


When do I use a heavy  and light viscosity oil?

Generally heavy viscosity oil is used with large clearances and lighter viscosity oil is used with tighter clearances


Can I have too much oil pressure?

Yes.  You only need enough oil pressure to keep a sufficient amount oil at the main bearings. Anything more is only wasted.


Does King offer Cam bearings?

Yes.  Our cam bearings are solid one piece Babbitt type including high performance versions.


Is it a good idea to use a high silicone bearing (SI/HP) on a nodular crank?

Yes. Silicone particles help reduce/eliminate microscopic ferrite peaks on improperly polished nodular cranks.


What King bearing material is best suited for steel cranks?

Both the HP & XP Bearing can be used with steel cranks.


What does King Bull’s Eye Tolerance mean?

King manufactures it product to the tightest wall tolerance in the industry.  +/- .0001” (overall .0002”) vs other manufactures +/- .00025”. (overall .0005”)


How King’s pMAX Black material can affect the journal surface?

– There is absolutely no effect or damage causes by Pmax Black to the journal surface. – Pmax black bearings differ from the competitive bearings due to a special surface treatment of the overlay. The treatment produces a strong ultrathin (nano-scale) skin which inhibits formation of fatigue cracks. Therefore load capacity of Pmax black bearings is at least 17% greater than that in the competitive racing car bearings. Hardness of Pmax black overlay is also higher than that of the competitive overlays (by 24%). – The value of hardness 18 HV in comparison to 11-14HV of competitors is still low enough to provide excellent anti-friction properties of the bearings (embedability, conformability and compatibility). For example hardness of aluminum alloy in bi-metal bearings is about 40HV. – The extremely low (nano scale) thickness of the hardened surface layer of Pmax black bearings guarantees that the journal surface can not be damaged (scratched) during metal-to-metal contact. If direct friction occurs the surface shield wears off from the overlay surface producing no scratches on the steel surface. – The effect of direct friction between tri-metal bearings (surface hardened and non-treated) and steel journals has been tested in King Test Rigs. The results proved total indifference in regards of the journal surface damage between the treated (Pmax black) and non-treated bearings.

 What does King Racing XP series consist of?  

King Racing XP series consist of rod & main bearings that  meet the most challenging demands  of today’s and tomorrow’s racing engines. Incorporating technologically advanced geometrical and metallurgical features, King XP race bearings  meet these requirements. See King Racing XP brochure for details.


Are King Bearings narrowed for aftermarket crankshafts?

Yes, All King HP and XP performance bearings  are narrowed to clear large fillet aftermarket crankshafts.

How to read King’s set label: