BW350b PSRU for 400 HP Engines

Auto PSRU's BW350b PSRU Specifications for 400 HP LS Engine Applications

Our PSRU products utilize our fully automatic, dry, centrifugal clutch which is the back bone of our system and the reason for our success. Our straight cut spur gear designs feature their own oil reservoir, oil pump and filtration system and built-in drive port for your hydraulic prop governor. All of our gearbox cases are CNC machined billet aluminum. These cases are lighter, stronger, and more beautiful than ever! Watch some of the machining process video sent to us by our machine shop.

The original BW350 had a cast aluminum case. The BW350a went to the current CNC machined case. The BW350b includes all the design improvements listed below.

The Centrifugal Clutch

The centrifugal clutch is the key to the success of this unit. The clutch operates due to the centrifugal force of the engines revolutions, so the pilot does no "shifting".

LS series V8 engines, having eight small lighter weight pistons that do not produce the violent engine impluses as those of the typical larger six cylinder aircraft engine pistons, offers the benefit of much milder engine impulses. These engine impluses are so much milder that the springs in the center of the clutch disc are sufficient to dampen harmonics. After all, the automotive industry has been using clutches to dampen harmonics between engines and transmissions for many years. Without a clutch in your transmission to dampen engine impulses between your engine and transmission, your car would hop and skip down the highway instead of rolling smoothly to your destination.

The higher the RPM's, the more firmly the clutch holds. The centrifugal weights are precisely balanced and designed to totally engage the propeller when the engine is running above idle. Disengagement happens only upon engine shut down and once the RPMs drop below approximately 800. As long as the aircraft is in flight the propeller will remain engaged. Because it will not free wheel in flight, you can use the propeller to slow the aircraft if you wish.

No more prop kick back upon start up or engine shut down!

Case dimensions

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Transparency of BW 350

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Improvements and Upgrades Since December 2012 included in BW350b

  1. Added seal retainers for both the input shaft and propeller shaft seals.
  2. Relocated the case breather   to the upper front of the case. This eliminates the problem of the old breather getting clogged up, reduces the required size of the breather, and allows increase oil capacity.
  3. Added an oil sight tube to the front of the case for easy checking of the oil level.
  4. Improved the Pressure Plate Assembly increasing the RPM limit from 4600 to over 6000 RPM. This is above the RPM limit of the engines valve train and the ECU rev limiter. It is also over 3600 RPM at the propeller which is beyond the limitations of the propeller.
  5. 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.
  6. 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.
  7. Additional improvements to the Pressure Plate Assembly were made to eliminate the tendancy of the centrifugal weights sticking for smooth reliable opperation
  8. A new oil filter mounting bracket has been developed to relocate the oil filter and eliminate any possible fatigue failure in the oil lines.
  9. A new drain hole was added to the bottom of the case and a new oil fill hole was added to the upper left side of the case to make changing and adding oil easy. Both plugs have safety wire holes and the drain plug has a high tempurature permanent magnet.
  10. Updated bolt design for installing the flywheel fingers making installation of the clutch assembly easier and eliminates frozen bolts for easier maintenance.


Auto PSRU's BW-350 PSRU for 400 HP Engines

Horsepower 200-400 HP for Experimental Application
Engine Applications Chevrolet LS1, LS2, LS6, LS3, and 5.3L Truck V8's as well as 4 cylinder V6 and Inline 6 engines, Ford 302, 351 Windsor, BMW - V12
PSRU/Redrive Weight 65 lbs
Centrifugal Clutch Weight 35 lbs
Prop Flange to Block Face 10.816"
Prop Shaft to Crankshaft C/L 7.687"
Reduction Ratio 1.667 : 1.00
Prop Flange All popular flanges
Lubrication Completely self contained, force fed by dedicated oil pump and filtration system, Included
Gear Type Straight cut spur gears
Prop Rotation Conventional
Clutch and Flywheel Assembly Included
Clutch Type Dry, centrifugal, dampens harmonics
Starter Type Lightweight, heavy duty, included
Price $15,100 plus crating/shipping
Delivery 90-120 days or less-call for lead times
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