Quick pictoral review of the Woessner Gen 1 Hayabusa 81mm bore off the shelf pistons. I have no knowledge of piston alloy,
strength of the piston, expansion, manufacturer reccommended ring end gap, etc.
These pistons are competitively priced with other shelf pistons.
Exterior packaging typical of a set of 4 pistons.
Interior packaging typical of a set of 4 pistons.
Spec sheet that came with the pistons. This is the only area where the Woessner pistons are lacking. The spec sheet just
doesn't contain enough information about the pistons such as compression distance, diameter of the piston, ring groove
dimensions and spacing, +/- cc of dish, coating information, etc.
I have mentioned this to John Noonan and he noted that the spec sheet will likely get better in time and that the retail
market is fairly new to Woessner. FYI, Compression Distance is 1.055".
Rings, Pin, Clips, etc, typical of a set of 4 pistons
Next, a few views of the piston:
Generous taper on sides of pin bosses
Anti-friction coating sprayed on skirt.
Gas porting on top ring evident in this picture. 8 gas ports total spaced around the perimeter in each quadrant
Piston crown is well finished. Almost all edges are pre-chamfered the only area that will need a any significant prep is in
the valve pockets near the center of the piston where it is difficult to machine a chamfer. A generous radius is machined on
the top edge of the "dish".
Pin bore conains two "lobes" at ~ 2:00 and 10:00 to aid in oiling.
Finish on the underside of the piston is also very complete. Almost all of the original forging has been processed.Note the
chamfers on almost all edges even on the bottom of the piston.
