Monday, December 29, 2008

Putting the pistons in the blocks


I went up to the museum Dec. 29th and got to see the new 25 ton GE delivered the next morning. It was kind of a day that you know was too cold to be out for long but you cant leave because it was so interesting.
After checking the fit on the rods one last time I went in the freight house and put the piston pins in connecting the pistons and the connecting rods. I put each piston/rod in the vice and put the new rings on the pistons. I had made a ring compressor for 6 3/4 pistons,from sheet metal and used a large vice grip to compress the rings. I was able to get the pistons in the blocks. It felt good to get that done.

Wednesday, December 10, 2008

Fitting Rods to the Crankshaft


To fit the connecting rods to the crankshaft, I turn the bare crank over using a tire iron in the teeth of the ring gear. When a journal is just past TDC I take the nuts off the connecting rod and remove the rod cap making sure the insert bearings and shims do not fall out. I put the top half of the rod though the hole in the top of the crankcase and reach through the hand hole on the side of the crankcase and put the cap on the rod. I hold the rod cap on with one hand from the top and reach through the side hand hole and put the nuts on the con rod bolts. This is not fun and a strech since the side hand holes are down in the loco frame. I reach down through the side hole and tighten the rod nuts with a 1/2 inch ratchet wrench inside the crankcase. After torqueing the nuts if the rod is too tight I have to take it out and add a shim. If its too loose I remove a shim. Do that 2 or 3 times on each con rod until the rod turn freely with no other play. It took a day and a half to shim the rods the first time. I took the rods home and decided that a couple inserts were rough and that there were better ones. I swicthed out the rough shells. I spent another day sitting on the crankcase fitting the rods. I took them home again and noticed a few of the shells moved laterally when the caps were bolted in place. I didnt want any shells moving when we were assembling the engine or running it. I did some research and decided to mount them in place using high temperature bearing mount. I used Locktite 620. After mounting the inserts I spent another day checking all the rods in the crankcase. They had changed a little bit and I had to shim two rods.

Monday, December 1, 2008

Insert Bearings


I spent most of the fall of 2008 fitting the connecting rod bearings to the crankshaft. I coud not find new bearings from the major manufacturers, Clevite and Federal Mogul. I would like to have a new set of bearings (number 12 187). The ID is 3.5 inches and they are about 3 and 1/4 inches wide. I bought brass shim stock, 7 thousands of an inch thick and cut 30 shims. To make the bolt holes in the shim without tearing them up, I clamped the shim in between 2 halves of the connecting rod and drilled though the bolt holes in the rod.. The design of the bearings is different from the babbited rods that I have worked with. To fit these bearings correctly the insert shells would be fit to a 3.5 inch mock up journal. Then the rod cap shimmed to fit the journal. I collected all the inserts that I could find from the 2 engines. Four of five sets of shells were destoyed from overheating and when the Whitcomb engine siezed. I matched up the remaining bearing shells by striations in the inside and outside of the shells. After pushing the pistons out of the blocks I numbered the rods and pistons trying to keep the pistons in the same holes that they came out of. I put the bearings in the rods and number the shells to match the rods.