Cylinder heads and Crosshead machine work
New Cylinder heads (front and rear) were cast to be thicker and provide better sealing. Each head had a "cone" that was added by Southern Pacific when the pistons were converted to a "light" design. The cones were cut off the original heads and will be welded back onto the new heads.
The crosshead is being machined to accommodate the new tapered wrist pins.
The cylinder saddle (not shown) also had a lot of machining work done last week. All the pilot holes for the taper pins (used to attach the cylinders to the frame) were drilled. The cylinders are getting close to being permanently installed on the frame!
|New front cylinder head casting as delivered and during machining|
|laying out location of cone extension to cylinder head. All four cone portions are being reused from old castings. These cones were added by the Southern Pacific when the pistons were converted to a light weight design.|
|New rear cylinder head casting during machining process.|
|Crosshead being set up on CNC machining center to re- machine correct taper for wrist pin, on centerlines with minimum material removal.|
|VIDEO of Crosshead machining (8MB, AVI file)|