5th Bearing Retro Kit


The Corvair 5th Bearing Retro Kit was originally designed by Dan and Jim Weseman to reduce the bending loads the propeller generates during flight and direct them into the case. In stock form the loads are taken between the #4 crank bearings and across the #6 rod throws. This configuration puts the load into the new 5th and #4 bearing, taking the bending loads off the over stressed #6 rod throw and directs it to the new front housing and engine case.  See MORE HISTORY HERE.

SPA has over 240 combined Generation 1 (Retro Kits) and Generation 2 5th Bearing kits installed on engines to date.

5th Bearing Retro Kit

Our Corvair 5th Bearing Retro Kit is designed to be installed on assembled Corvair flight engines.

If you are assembling a new engine see our 2nd Gen 5th Bearing Option HERE.

 5th Bearing Retro Kit for Assembled Corvair Flight Engines


  • CNC Machined Billet Front Casting with Standard Size Bearing Installed
  • Heat Treated 4340 Bearing Hub
  • Oil Seal
  • Oil Inlet Fitting
  • Complete Instructions

(Fulfills FlyCorvair Part Number 3001)

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Installation Kit

The installation kit is required for a successful installation of the 5th Bearing Journal and Housing.  This includes drills, reamers and guides, dial indicator and mount to install the housing and dowels quickly and accurately.  The kit is free to use, we simply charge $20 for shipping.  We charge a refundable fee of $150 for the kit and refund the amount to you once the kit is returned.

William Wynne style Gold or Black Hub Mod

To get your WW style gold (2501A) or black hub (2501B) modified to use stock safety shaft and hybrid studs CLICK HERE 

This also retains prop flange location.

(Fulfills FlyCorvair part # 3002 or 3003)



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