superior air parts slogan

We put the same quality and

care into our factory new

XP-Engines that 

you put in your homebuilt.

Better features. Better benefits. Better value from Superior’s XP-Engine series.

XP-Engine_generic_photo.jpgEach factory new XP-Engine is created from the most advanced designs and manufacturing techniques then individually hand assembled by experienced engine craftsmen using many of the same FAA certificated parts used to build the FAA certificated Vantage Engine. 

The components used to create Superior’s XP-Engines are the culmination of literally hundreds of individual design and manufacturing improvements we have made to our array of FAA PMA-approved parts and components over the last 40-plus-years. 

Today, the fit, finish and quality of all of our parts and components are of the highest possible quality and consistency. Our parts and components are not painted or alodined to hide blemishes or manufacturing shortcomings. The only reason we paint our Millennium Cylinder barrels or Alodine finish on the cylinder heads, crankcases, sump, cylinder heads and assembly drives on the XP-Engine is for corrosion protection. 

Why? The reason is simple: we have the best looking parts in the business and we don’t have to cover up any manufacturing flaws with paint. 

The obvious quality of the XP-Engine is just the beginning of the many performance and quality advancements it brings to piston-powered, experimental aircraft and helicopters.

Other examples of the XP’s many standard features and benefits include: 

Reinforced Crankcase


SAP_Mark_2C_Icon.jpg Direct lubrication available to the thrust face greatly reduces crankcase and crankshaft wear

SAP_Mark_2C_Icon.jpg Balanced oil system provides uniform lubrication to both sides of the crankshaft and camshaft. This reduces pressure fluctuations while equalizing oil-flow through the entire engine, including the filter

SAP_Mark_2C_Icon.jpg Reinforced cylinder deck strengthens key areas against crankcase pressure and helps eliminate cracking

SAP_Mark_2C_Icon.jpg Precision machined to accommodate cooling nozzles for high-compression piston and turbocharger applications.


Proprietary ESR Crankshaft


SAP_Mark_2C_Icon.jpg Electro Slag Remelt (ESR) process removes many more metal impurities than the standard Vacuum Arch Remelt (VAR) process used in the production of most prior-generation crankshafts

SAP_Mark_2C_Icon.jpg Oil journals are polished and coated to virtually eliminate the corrosion and pitting issues that were prevalent in many VAR produced crankshafts

SAP_Mark_2C_Icon.jpg Each crankshaft is balanced within exacting tolerances to ensure the smoothest engine operation throughout the power operating range.


High-flow oil sump 


SAP_Mark_2C_Icon.jpg Smoother intake manifold and plenum reduces aerodynamic turbulence for better breathing for all four cylinders

SAP_Mark_2C_Icon.jpg Unique plenum turbulator improves air-fuel mixing

SAP_Mark_2C_Icon.jpg Tuned intake tubes balance the intake runner length to further improve airflow and engine breathing

SAP_Mark_2C_Icon.jpg Polished, stainless steel tubes minimize rust and corrosion.


Horizontal Cold Air Induction System (Optional)


SAP_Mark_2C_Icon.jpg Air plenum is separated from the main sump body to keep inlet air cooler to provide more horsepower

SAP_Mark_2C_Icon.jpg Horizontally mounted fuel injection system allows builders to create more aerodynamic cowling designs

SAP_Mark_2C_Icon.jpg Lighter weight than conventional sumps

SAP_Mark_2C_Icon.jpg Machined to allow for installation of inverted oil systems. 


Millennium Cylinders


SAP_Mark_2C_Icon.jpg Through hardened steel barrel provides uniform hardness all the way through the barrel walls, ensuring even wear while withstanding extreme temperature and pressures

SAP_Mark_2C_Icon.jpg Very high quality casting creates aerodynamically smoother surfaces to improve overall airflow and cooling

SAP_Mark_2C_Icon.jpg Exhaust and intake ports are volumetrically matched for maximum output and performance

SAP_Mark_2C_Icon.jpg Computer-generated head fin configuration for more efficient heat transfer and fewer “hot” spots

SAP_Mark_2C_Icon.jpg Increased port wall thickness eliminates issues with warping and cracking

SAP_Mark_2C_Icon.jpg Manufactured from the most advanced alloys available to exceed industry standards for strength and porosity.

For more details on Superior Air Parts Millennium Cylinders click here:

 Millennium Cylinder page


Computer Optimized Camshafts


SAP_Mark_2C_Icon.jpg Superior’s camshaft is designed for better cruise economy, lower valve-train loads and smoother idle and power operation

SAP_Mark_2C_Icon.jpg Lower valve-train loads reduce camshaft and lifter spalling while decreasing wear and friction to the valve-train and guide

SAP_Mark_2C_Icon.jpg Precisely timed camshaft lobe valve events eliminate re-ingestion of exhaust gasses, improving economy and overall performance

SAP_Mark_2C_Icon.jpg Idle and power vibration characteristics are also computer optimized to “passenger car” standards to reduce vibration, pilot fatigue and component wear.


Roller Lifters

Our roller lifters were developed to provide a smoother running engine and to help reduce wear between the camshaft lobe and the roller face, minimizing the occurrences of cam-lifter spalling.

SAP_Mark_2C_Icon.jpg Superior Exclusive!

A unique feature of our roller lifter design is that they can be removed without opening the engine case, which reduces costly maintenance and repairs.


Connecting Rods


SAP_Mark_2C_Icon.jpg Precision machining of the entire connecting rod surface a better finish and more consistent weight and balance

SAP_Mark_2C_Icon.jpg Forged 8740 steel per AMS 6325

SAP_Mark_2C_Icon.jpg Individual connecting rods are statically and dynamically balanced

SAP_Mark_2C_Icon.jpg Tongue and groove design reduces shear loads.


Component Balancing and Matching

SAP_Mark_2C_Icon.jpg Connecting rods are individually statically
and dynamically balanced

SAP_Mark_2C_Icon.jpg Crankshafts are balanced to within
¼ ounce-inch

SAP_Mark_2C_Icon.jpg Connecting rods, pistons, piston pins, connecting rods and bolts are all weighed and balanced as a set to closely match the weights of all opposing components results in smoother engine operation.


Tri-Metal Bearings

SAP_Mark_2C_Icon.jpg Tri-Metal Bearings are 40% stronger than conventional aluminum bearings.


Superior’s Machined Parts versus the competition’s cast parts.

Superior has elevated the production of many seemingly simple parts to a higher art. For example, instead of using lower cost and quality processes including casting and painted, or plastic (filler tube) processes, and materials like our competitors, we have machine numerous parts from billets and then alodine these parts against corrosion.

Superior billet-machined parts include:

SAP_Mark_2C_Icon.jpg Oil filler tube and level gauge

SAP_Mark_2C_Icon.jpg Vacuum pump drive

SAP_Mark_2C_Icon.jpg Oil filter adapter

SAP_Mark_2C_Icon.jpg Prop-governor drive

For more information about Superior XP-Engines, please contact:


*NOTE: Superior XP-Engines are approved for 100LL Avgas per ASTM D910, 91/98 (lead optional) and motor gasoline with a minimum antiknock index (R=M/2 method of 91 per ASTM D4814 (European EN228). Use of auto fuel blended with alcohol (ethanol) is forbidden.

  • The XP-360 Engine® series, when operated with pistons of 8.5:1 or lower compression ratio, can operate and perform at rated power using unleaded auto fuel. Engines with a compression ratio of 8.5:1 must be operated on a minimum of 91 Octane auto fuel. Engines with compression ratios of 7.2:1 or lower can operate on a minimum of 87 Octane auto fuel.

  • The higher the octane used in the XP-360 Engine®, the greater the detonation margin during high power and/or hot operation. When operating on unleaded fuel, Superior recommends using fresh, premium, auto fuel available at a major brand, reputable gas station.

® XP-Engine, XP-320 and XP-360 are Registered Trademarks of Superior Air Parts, Inc.
® Millennium Cylinder is a Registered Trademark of Superior Air Parts, Inc.
® Vantage Engine is a Registered Trademark of Superior Air Parts, Inc.

superior air Parts Search

  • Over 2,000 FAA-approved PMA parts and components available
  • Manufactured with the most advanced materials
  • Sold through a global network of dealers and distributors

superior air Millennium Cylinders

  • Advanced aluminum alloy heads
  • Computer-generated head fin design
  • Through hardened steel barrels
  • 37 month warranty

superior air Vantage Engines

  • FAA certified
  • 180-horsepower
  • Runs on Avgas or automotive gasoline*
  • Millennium Cylinders®

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