My timing side crankcase was broken, and the previous caretaker had epoxied it back together. This was part of the discovery phase way back, and now it is time to address. I had sourced a case half and checked alignment, measured my crank, measured bores, skirts, and ring gaps, but was still tentative about the build. I had talked to George Yarocki a couple of times on the phone, and decided that if he had any time available I would go see him for an evaluation. I needed to get out of town for a few days anyway. He was agreeable, so I loaded up a box of motor parts, and Sunday am of labor day weekend I headed to CT. I would spend a day or two, meet the guru of all things 101, and put my lower end together. What could go wrong?
Our first order of business was a quick tour. It truly is amazing the amount of time and thought George has put into his place. Everything is labeled, orderly, and clean. Parts were everywhere, lots of stuff I had been trig to find. Next we unloaded my boxes, and inventoried what I had. Then started with the cases.
I had welded the baffles back in the cases, and welded them on the top side. I was not aware the piston skirts dropped that far down, and they were hitting at bottom center. Now the next item that reared its head, was the case halfs lined up perfect on the crank bearings, but the cylinder bores were off. After some discussion, we decided the sourced case for the timing side was a 37 cu-in and mine are 45 cu-in. Since that was only a small inconvenience, we set up to remedy the problem.
After making a fixture to center the cases in the mill, we bored the 37 case to a 45, and cut the high spots off my welds.
It took all day, but by the time we were through, we had a good set of matched cases, with new bearing races and good clean case bores! The long ride in the truck was now justified.
Next, I wanted some help setting up the crank. Centering the rod inside the crankcases is critical on these motors, and I wanted to learn about it. First we had to build a crank. I wanted a bullet proof bottom end, and had decided to use new pins, wheels, and rods for the cannonball. I assembled the crank with Truett Osboure flywheels and carrillo rods.
Carrillo Rods honed for new races.
On first assembly, we ran into problems. We were trying to measure the end play of the rod, but instead found the rod was hitting the crank and binding. So back apart it came, and we finally found the problem. I knew people have used Carrillo sport scout rods before, but these were defiantly hitting the crank. It seems the carrillos are just a little beefier than stock, and the TO flywheels are a little beefier that stock, and the combination rubbed. The stock flywheels have a recess dished into the side to allow the rod to clear, and the TO wheels don't, so a die grinder was enlisted to remedy this problem. A couple of attempts, then a couple of test assemblies grinding thrust washers, and we had a good crank.
Run out was way less than .001", and the assembly balanced nice!
George was adamant that the rollers in the bottom end all be miced. So I selected 120 rollers all within one tenth of a thousandth, or .0001". I was surprised how much variation there was in new rollers.
Measuring the case depth.
adjusting the thrust washers
With all the tolerances correct, shaft end plays correct, crank true and balanced, and case half's matched I assembled the motor one last time. I really feel good about this motor now, and have defiantly learned my way around the inside of a 101 Scout motor. But best of all I got to learn from a true craftsman, and I thoroughly enjoyed every minute of it.
George had told me way back on Monday that I would assemble and take the motor apart 17 times before we were thru. I wish I would have counted, because I don't think he missed it far!
