While doing research for the previous posts on the EMD 567 engine, I came across a short article written in 1958 on the Burlington Railroad’s power assembly overhaul shop in West Burlington, IA.
What’s interesting is Burlington used a converted 14″ American Pacemaker engine lathe to bore the cylinder liners in one operation. The article states:
Liners removed from the lye vat are placed eight on a special trailer for sand blasting. Water ports on the C liners are protected by steel plates, and liners with lower seals have the seals left in place for this operation. After being returned to the conveyor line, they are checked and marked for rebore, honing or scrapping.
Ridge reaming is not done. Instead, rebore operations are based on 0.030 in. and 0.060 in. oversizes, then the liner is scrapped. Liners worn about .004 in. are honed. In this case, the port relief zone is not touched. Liners are then wiped clean, lower seals removed (uppers seals are left on for a water test), and they are moved on the conveyor to an American Pace Maker lathe adapted for boring. The boring (unreadable) roughing and finishing tool, and does the job in one operation, including the port relief. No honing is done after boring.
The next operation is an 80 psi water pressure test. Following final cleaning, studs are inspected and checked for length. All seal surfaces are wire brushed. The edges of holes on the inside of the port relief zone are chamfered, and the new size is restenciled on the liner. From here they go to assembly. The present output of rebored liners is 16 per day.
I’ve always thought American Pacemakers, especially the post-war machines, were the best heavy engine lathes ever built. Despite having been in service over 40 years, my machine still holds tolerances normally associated with cylindrical grinding machines.
How is that possible? American’s unique system of hardened tool steel dual prismatic ways:
I’m also rather partial to the Pacemakers because I own one and hope to own at least one more. Many parts of the Paulding Racer will likely be produced on this machine.
You can read more of the 1958 West Burlington power assembly overhaul shop article at the link below. Unfortunately, the pages have been cropped so it isn’t possible to determine where the article was originally published. If you have any information on the article so I can properly attribute it, please let me know.