The most advanced PSRU’s available for 150 to 300 HP Engines.

Advantages

  1. Centrifugal Clutch
    1. Engages & disengages at 800 to 900 RPM
    2. Eliminates high starter loads and burnout
    3. Eliminates propeller kick-back & damaging harmonics
    4. Makes the engine think it’s still in a car
    5. Clutch stays engaged so propeller can be used as a speed brake.
  2. Straight Cut Gears
    1. Most efficient transfer of power
    2. Eliminates fwd/aft thrust loads into drive shafts and into front and rear of case reducing weight
    3. Light weight heat treated gears for maximum strength and crown shaved for quiet operation
  3. Separate Lubrication System
    1. Allows the use of proper gear lubricants
    2. All bearings (100% roller) are pressure lubricated
    3. Eliminates extra heat load on engine oil
    4. Supports hydraulic constant speed propellers
  4. Multiple gear ratios available
    1. Uses two gear sets available in 64 gear ratios making 150+ gear ratios from 1:1 through 3.54:1
    2. Multiple gear rations makes it very flexible for any engine between 150 and 300 HP
    3. The case is designed to be used with an adapter making it easy to mount on any engine.
    4. Typical applications are 4 cylinder Subaru EJ 2.5L, 6 cylinder EZ 3.0L engines, Mazda 13B engines.
    5. Fuel burn is 30% less per hour, plus higher cruise and maintenance costs are 90% less

PSRU for Eggenfellner Subaru Replacement to Retrofit Gearbox with Centrifugal Clutch and Flywheel Assembly

The Auto PSRU’s  200Z Zero Offset PSRU for Subaru was developed as a replacement gearbox for Eggenfellner Subaru 4 and 6 cylinder engines. This gearbox has all of the same features of our original BW-350 PSRU, including the centrifugal clutch and flywheel assembly, plus all the new features listed below that make it the 200Za. With this new PSRU, Subaru engine owners no longer have to tolerate the torsional vibrations that many have considered “normal”. Smooth and quiet operation, the double reduction gearbox offers over 150 different gear ratio choices. Gear ratios are easily changeable by returning the gearbox to Auto PSRU with your ratio choice. Charges for gear ratio change out are approximately $900 done by AutoPSRU’s.

The multiple gear ratios available means the 200Za can be adapted to any engine up to 300 HP. Please consult with us if you have any doubt on the best ratio for your engine.

Aircraft owners flying this gearbox report:

“No bad harmonics”
“Better fuel burn with cruise speed at lower prop setting”
“Starting is much nicer, and stopping now does not have the death shudder!”
“Temperatures for oil, water and GB much lower”
“Because it’s now so quiet I guess we can hear all sorts of things – it’s
nice not to have any bad harmonics!”
“No vibration felt on the airframe as you can touch the dash and it’s smooth”
“Much fun and sooo smooth”
“No rum rum rum harmonic”

Lee Apaka graciously allowed us to use photos (above) of his beautiful RV7 flying the Auto PSRU’s 200Z PSRU on his H6 Subaru Boxer engine, and sporting some fantastic new radiators by Ed Klepeis of Tech Welding in Paducah, KY. Lee reports fantastic engine cooling using this radiator and cowl configuration.

Check out this youtube video of Lee in his airplane in the skies over California:

To see a pdf documentary of Lee’s experiences as he replaces the Eggenfellner Gen III gearbox with the Auto PSRU’s 200Z PSRU click here…it is 47 pages long so be patient and give it time to open up.

Click here to view and download the Installation Manual

If you would like to know more about how to improve Subaru engine cooling log on to http://www.techwelding.com/index.html or call Ed Klepeis at 270-898-3776.

Please feel free to call us at (936) 827-5126 if you have any questions or comments, or email Stuart@AutoPSRUs.com.

Click here to see the 200Z Auto PSRU’s Zero Offset Gearbox being test run on Frankenstein, our test mule. We are running it with a 72″ Hartzell two blade hydraulic prop on a 350 Chevrolet engine under full load at full pitch. After 8 hours running non-stop, you can wrap your hand around the oil filter and it is barely more than body temperature to the touch.

The gearbox bolts on via an adapter plate. Your starter remains in its current location under most circumstances. Gearbox can be used with or without the Eggenfellner front engine mounting plate. (Front engine mounting plate not included, shown below for clarity)

Improvements and Upgrades Since December 2012 for the 200Za

  1. Added seal retainers for both the input shaft and propeller shaft seals.
  2. Added an oil sight tube to the left side of the case making it easier to check oil level, and add oil if needed.
  3. The oil plug on the upper right side of the case now has a breather fitting.
  4. Tested synthetic versus standard lubricants and found that synthetic lubricants run slighter cooler and resisted foaming much better even at 75/110 versus the old 85/140.
  5. Tested three different oil filters proving the old filter was the main cause of foaming in the lubricant. A new filter is now the standard for all of our gear boxes.
  6. Made additional improvements to the Pressure Plate Assembly to assure smooth and consistent operation of the centrifugal weights.
  7. The standard oil drain plug now has a magnet in it.
  8. Updated bolt design for installing the flywheel fingers making installation of the clutch assembly easier and eliminates frozen bolts for easier maintenance.
  9. Added a sight tube with markers for full and low making it easy to check the lubricant level.

Auto PSRU’s 200Za PSRU for Subaru Engines

Horsepower150-300 HP
Engine ApplicationsSubaru 2.5L 4 cyl & 3.0L 6 cyl, Ford and Chevy Inline 6 cyl, Mazda Rotary, adaptable to others requiring zero offset from prop flange centerline to crankshaft centerline via engine mounting plate
PSRU Weight2 lbs lighter than Egg Gen III (with flywheel) at 70 lbs (with automatic flywheel/clutch assy)
Prop Flange to Block FaceSame as Eggenfellner
Prop shaft to crankshaft centerlineZero inches
Reduction RationOver a dozen possible, engine specific, please inquire
Prop FlangeAll popular bolt patterns
LubricationCompletely self contained, force fed by dedicated oil pump and filtration system
Prop rotationConventional or counter rotational
Clutch and Flywheel AssemblyIncluded
Clutch typeDry, centrifugal, dampens harmonics
Delivery90-120 days typical, call for lead times

PSRU 40 lbs, Flywheel Assy 30 lbs.
Total 70 lbs (dry), 2 lbs less than Eggenfellner.
Firewall Forward Packages Available, pricing details on website for Subaru and Mazda engines.

Zero offset design – the input shaft and
propeller are on the same vertical plane
Perfect for horizontally opposed & rotary engines
Call for pricing.

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