The Excelsior Project, 41: Testing the Engine

The engine is installed. Excitement is building ...

Electric starter. Comes from a Sportster. Plugs in to the countershaft sprocket .

June 30, 2007

Pete and I got the motor into the frame, and hooked up the gas and oil lines. He timed the magneto, and discovered that one of the 80-year-old spark plugs had no spark, so it was taken apart and fixed. We took the Excelsior outside and put in fuel and oil. The 1920s Schebler carb was leaking gas out of the float bowl, so that needed attention too. I found a fire extinguisher, just in case. Pete operated the throttle and mag advance, and I plugged the hi-torque Sportster starter motor into the crank. This was the moment, and I pressed the button. The starter motor was really straining, the big V-twin barely turning, and then it suddenly spun a few revolutions and fired up! It is loud! Doesn't sound like a Harley either.

The motor ran, but the linkage still wasn't finished. These little pieces were very tricky to machine from 303 stainless. Hard part is figuring out how to hold them.

Here they are, in place, with the rest of the linkage.

After startup, the motor had to be pulled apart to see what was going on inside. It looked like the piston clearance was too small; the pistons were showing signs of seizure, and the Nikasil needed honing. It didn't look like the oil squirters were working either, so that needed checking out. The oil pump was setup in the milling machine to check oil flow, and I discovered my BIG mistake. I had copied an Aermacchi oil pump, which was fine, but I had got the rotation backwards, so the Excelsior oil pump was running backwards! (horror of horrors...)  I had already sent out the invitations for the official startup party on Sunday, July 8, so there was very little time to solve the oil pump and piston problems. It was back to working 8am until midnight. The barrels were honed out .002" for a total of .006" clearance. There was no bronze (the right size.. ) available in town, so I couldn't machine up another oil pump, I would have to modify the existing one by plugging existing oil galleries and machining new ones. The oil squirters were now working, but the pump was cavitating badly, so I had to go online and learn about machining anti-cavitational grooves to solve the problem. The engine was reassembled and installed into the frame at 11pm the night before official startup.  There was no time for additional testing.


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