Mike Grimes, Lancaster, CA has recently completed an overhaul on a LeBlond 7 cylinder 7D iron cylinder 90 HP engine for Rick Livington's St. Louis Cardinal. Rick and the aircraft are at Columbia Airport in California. Folks who fly "Lil' Round Engines" in Rearwins, Porterfields, and a few other types using LeBlonds know how much work it takes to get a good engine. Here's Mike's story on the engine overhaul:
When the engine was originally torn down about six years ago it was found to have a cracked crankshaft, master rod and one piston. Not knowing how or where to get replacement parts the cleaned parts were reassembled to make a static display engine.
When the engine was placed in my hands I was able to locate the required parts through the generous help of a lot of friends and their contacts. The worst part was that the engine had been previously been worked on by a person(s) who had no business being near an airplane, much less working on one. All of the front cover studs had been stripped out of the crankcase and replaced with bolts that had about 2/3 of their heads ground off. Several of the cylinder hold down studs had been stripped also. The crankcase had to be set up in a P&W jig borer in order to recut the stud holes with an end mill so they could be helicoiled to again accept the proper studs. The accessory case studs had also been stripped out and the holes retapped to 3/8". This required making custom studs with 3/8" threads on one end and 5/16" threads on the other end. There was not enough metal left in the case casting to allow for overboring and installing thread inserts.
The replacement master rod was a late style that takes bearing inserts. It was in an unfinished condition so some machine work and polishing had to be done to complete it along with making a new pin bushing. Off the shelf bearing inserts were acquired to fit the rod and crankpin combination.
The replacement piston was +.020" oversize and had to be machined down to standard size.
The replacement crankshaft was from a 5 cylinder engine so after magnaflux, polishing and shot peening the old 7 cylinder counterweights were installed on it.
All of the valves were worn out or ground to a razor edge so new valves were made using Ford valves as blanks.
Several valve guides had to be made to replace guides that were loose in their respective heads. This engine has one piece, cast iron, cylinders with integral heads. The original paper cylinder base gaskets were discarded and the cylinder bases sealed with O-200 cylinder base O-rings. All new paper gaskets were made for the crankcase, accessory case, oil pump and magneto drive joints. Rick says it doesn't leak much oil but it certainly flings grease in every imaginable direction.
This is an old two main bearing engine so it will only be a matter of time before the crankshaft cracks or breaks from precessional loads. Hopefully the polishing and shot peening will lengthen its service life.
Rick has installed the engine on the early model St. Louis Cardinal and has run it. He's now waiting on a propeller before flying.