|The Cannonball Rig has found a new home..sweet memories|
|A very special thank you to our family in the Confederate|
Chapter of the AMCA for this extremely special award
Our Cannonball bike has enjoyed a warm reception in the several motorcycle shows and events that she's been displayed at. Our very first event was the 2012 Barber Vintage Festival, where our extended family at the Confederate Chapter of the AMCA invited us to display our bike and mobile machine shop for the public to see. We were honored when the club presented my dad and I with the "Atta Boy" award for our service to other teams during the race. Next up on the docket was a local car, truck, and bike show where the BSA won the coveted "Ladies Choice" and first place trophy in its motorcycle class. Finally, my friend Joe Sparrow, who was a roadside savior many times during the Cannonball invited me to bring Elizabeth down for display at the J&P Cycles Storefront during the 2012 Lone Star Bike Rally in Galveston, Texas. Joe and the gang took very special care of her for the duration, and she received plenty of
attention from the crowds. Now that winter has arrived, I can finally give the bike the much-needed rebuild that it deserves.
|I knew when I saw this sign that Elizabeth was in good hands....|
|On display in front of the J&P Cycles storefront during the 2012 Lone |
Star Rally in Galveston, Texas. Special thanks to my friend Joe Sparrow
for the invitation, and for taking such special care of my lady.
With the end of the race, Elizabeth lay pretty torn, tattered, and beaten. Over the course of 2,557 miles we burned through two pistons. The first of these pistons, a NOS original that was sourced in England, was removed in Sturgis, South Dakota. Excessive mountain grades, hard running, and high temperatures in the cylinder melted the oil ring and led to multiple seizures in under three miles. We replaced that piston and rings with the brand new machined setup from JP Pistons in Australia. An interesting note: the second piston was actually quite a bit heavier than the NOS unit, and JP rings haven't had the best reputation. When removed and examined, we discovered that this piston had gotten so hot that the gudgeon pin partially melted to the small end bush and the side of the piston skirt had been badly scored.
- Motorcycle Mechanics 101-
- Question: "What causes a massive failure with the piston and gudgeon pin like this?"
- Answer: "Heat, obviously."
|Piston number one: Note the melted oil ring...ouch!|
Okay, so this kind of extreme heat can come from only three major areas. Firstly, a motor that is incorrectly timed will either detonate the mixture too early or too late, creating vast variances in the heat. A fuel and air mixture that is too weak can easily be a source for major heat, often leading to holing the piston. Finally, and the problem with Elizabeth, lack of lubrication is major no-no. That being said, what caused the oiling to be incorrect? Here's the long and short of it. Part of the blame probably lies on me, but a major reason comes from a design flaw.
|And piston number two: Check out the small end bushing |
on the gudgeon pin
Lubrication systems on these 1920's Brit bikes aren't exactly up to snuff for a happy motor, and definitely don't like to be beaten up over 4,000 miles. Most early four stroke motors relied on "splash oiling," where the flywheels dip into the pool of oil at the bottom of the crankcase and splash it up. Not opportune. If you'll recall, the bike has a combination of manual and "automatic" oil pumps. In 1927, BSA recommended that riders utilize the automatic pump as a primary, with the manual oiler as a supplemental. Drip rates on the automatic pump can be set with the top mounted control knob, and I usually varied from one drip every three seconds to one every 6-8 seconds. Used in conjunction with the manual hand injector, the effectiveness on the oiling was minimal to say the least. What I found was that not enough oil was making its way to the top end of the motor and more often than not, the piston and gudgeon pin were under-oiled. Aggravating still was the fact that this condition varied without me even changing the settings; one day would have the motor running at a normal operating temperature with semi-effective oiling, then the next would have it way under-oiled. To try and combat the lack of oil to the piston, I used three different methods.
- Usually with every fuel stop I would add about an ounce of 2 cycle engine oil in with the petrol. This small amount injects oil directly to the top end of the motor through the carburetor mixture, and also provides an efficient way to keep the slides and jets of your carburetor clean and lubricated)
- With the small oil can that I carried in my panniers, I would douse my tappets, valve stems, and valve springs with oil at every few stops. This small bit of oil would eventually make its way to the combustion chamber.
- While riding, I periodically closed the air and fuel levers momentarily. This lapse creates a vacuum that sucks oil from the crankcase and big end to the top of the engine.
Overall, the lubrication system on these old sidevalvers is pretty much "hit or miss." Towards the end of the race, after we installed the newly rebuilt motor, I learned something new about the oiling. At times, the drip rate will actually lie to you. What looks like one drip every 3 seconds will actually be a constant flow of oil. Five minutes after an easy start with no problems, the motor will start oil fouling plugs left and right. Upon further examination, you'll discover that your brand new crankcases will be completely full of oil, and your oil tank empty. It took several times of almost ripping my hair out before we finally figured out the cause of the problem. The exterior oil pump body contains a worm drive towards the bottom of the pump, which is what stops the flow of oil when the tap is turned off. During the rebuild, the drive had somehow worked itself loose and was allowing oil to bypass the pump. Once firmly set into place, it was back to life. It's always something with these old machines...probably why they're so addicting to me- how to solve problems
Overall, the problem was diagnosed...poorly performing lubrication system. Now, how do we go about addressing it? Well, I'm down with a sinus infection, so I'm feeling pretty beat at the moment. That'll just have to wait and be the subject of my next post. Stay tuned, caped crusaders.
Cannonball Rider #3
Carson Classic Motors Race Team