786 restoration Progress

All 4 cylinder heads are being replaced and strengthened. Inside each head is a "cone extension" that matches the profile of the piston. The purpose is to reduce the volume in the cylinder when the piston is at top/bottom dead center. This improves the efficiency of the engine. The cone extensions were earlier cut out of the original cylinder heads and will be welded onto the new heads after all the machining is done.

After some minor delays (vacations & machine availability) work resumed on machining the cylinder upper frame rails and we are now getting 8 hrs per day. Current schedule has this pace continuing as the mill is operating 24/7. Photos to follow.

The attempted repair to the drawbar casting was started and stopped. It has been determined that is is better to make a new drawbar casting rather than continuing to try to repair the old one. Currently the drawbar casting with drawings are at the pattern maker and a pattern for a steel casting is about 8 weeks out. This is a fairly complex casting. Here is a photo of the original drawbar casting. We'll add photos of the new drawbar as available.

The smokebox bottom has been delivered to Bob Yuill, Historic Machinery. It has already been drilled to mate to the cylinder saddle. Bob will weld it on to the bottom of the smokebox for later assembly.

New front and rear cylinder head castings are almost complete at the casting house and will be deliverd to TMC for machining. The preliminary drawings have been completed.

Photo shows one new rear cylinder head casting in the steel shot blaster during cleaning. The round boss areas below are casting risers required for metal flow and will be removed prior to shipping.

Photo: Steam Operations Corporation

Cylinder head inside cone extensions being repaired and machined flat at TMC. When new cylinder head front and rear castings are machined these cones will be welded on to obtain correct clearance of the piston to the cylinder heads front and rear. These extensions were applied when the piston was changed from a standard three piece bull ring style to a modern light weight design.

Photo: Steam Operations Corporation

New cylinder heads arrived at TMC on 6/1/09.

Photo: Steam Operations Corporation

Ronnie Jones truing up piston ring grooves. The replacement LFM Universal Packing rings per the new original cylinder bore and the repaired grooves are designed and in the CAD program.

Ongoing:

In addition we are using CAD to position the pistons with the rings in the new cylinder bores to finalize the ring location at each end of the stroke to determine the exact location of the counter bore location vs over travel of the piston in the cylinder. This needs to be complete prior to final boring the cylinders and counter bores.

Photo: Steam Operations Corporation

Machining piston ring grooves true for application of new rings.

Photo: Ronnie Jones LTMC/SOC

Terry Allen welding tire clips to wheel centers.

Photo: Ronnie Jones LTMC/SOC

Repairing broken weld on threaded plug on back of crank pin needed as a grease reservoir for the rods.

Photo: Ronnie Jones LTMC/SOC