Focus this week: COMBUSTION
In Lab Last Time
Forks: Used the parts cleaner to remove the grease from the forks. Unscrewed collars of the fork: tried a strap wrench, then Al used a machine to make the proper tool using the shape of the collar
Wheels: took off speedometer, unscrewed bolts, took out the wheel barings with a hammer, tried to press down in the valve to release the air, then removed whole value
Clutch: worked to get off the cover off of the timing side in the bottom part of the engine. Used manual impact wrench
Fasteners: measuring the engine cover to make a gasket, wasn’t successful
Bottom End: removing casing on the timing side with the clutch team, drained oil still inside the engine (there are 3 oil chambers – oil reserve tank (reservoir), center chamber where the transition is – lubricates parts, reservoir on the clutch side – lubricates and cools clutch parts)
Top End: separated head of the engine from the bottom, took off top of the piston, took apart rocker assembly, valves removed
Electrical: figured out how bullet connection works
Frame: took off little parts of frame, tried to use arbor press to push out the swing arm pin, but it was in too tightly. Used hydraulic press to push it out
#1 priority for this time: we want to get the black parts ready to be powder coated.
Chapter 2 in Shop Class as Soulcraft
No motorcycle references
Ale K: Making what used to be craftsmanship into work that requires less skill. This is what has made manual labor less valued – people don’t think about craftsmanship.
Ellie: Low labor cost is valued. Takes away from craftsmanship, too.
Diego: There are jobs that are hard to replace with machinery, but we’re on that trajectory
Prof. Littman: Governments and corporations attempt to mechanize work: increase volume and decrease cost
Ale K: More trade-based training in prisons? Standardized testing doesn’t allow for considerations of individual difference
Diego: Introducing human variables has economic risks
Izzy: Once you start moving from humans to machines, where do you stop?
Prof. Littman: Interesting discussions here about expert systems. You clearly don’t want to have people replaced entirely. What happens when computers make all the decisions in our lives?
Jamie: This is like Zen – fear of technology and its future.
Izzy: I agree. It’s not a really realistic view but it’s healthy to have a sense of apprehension.
Prof. Littman: p. 51 – creativity is the byproduct of mastery of the basics
Preston: Do you think we will always need skilled laborers, Prof. Littman?
Prof. Littman: From a consumer POV, we probably don’t. We just replace things instead of fixing them. But we have to pass down knowledge to the next generation.
Triumph Tiger Cub Engine Calculations
Prof. Littman demoed the ping-pong rocket!
– Vessel filled with water and a bit of acid
– If you hook a battery to water, the positive electrode will attract OH– and the negative one will attract the protons
– Columns filled with H and O, lit spark (increased pressure), ping-pong ball flew
Grace: Gasoline reacts with oxygen to produce carbon dioxide and water vapor
Prof. Littman: CC = cubic centimeters, our engine is 200 cc or 1/5 liter. This is a square engine- roughly 6 x 6 x 6
Diego: energy released is based on air-fuel mixture. Proportion of fuel to air can give you different powers
Parker: Air-fuel ratio is 15
Prof. Littman: It’s done by weight. A gram of fuel is 44K Joules. That’s a lot! (Boxer’s punch is 4J.) Take that fuel, react it with air, and the horsepower of the engine that is released is 50 J if none is wasted.
Parker: When you combust the fuel it heats up the engine block and you lose some energy.
Prof. Littman: Also, hot gas comes out of the engine. 1/3 of what’s available is what you get. If you run the engine faster, you get more horsepower (more explosions for time). THE most important thing about engines: the amount of oxygen. Engine breathing: take a gulp of air, react all of the air is the best you can do. If you want more energy per explosion, add more air.
Chris: You could pressurize the air or use a different fuel with higher Joules/gram.
Diego: Or a bigger engine.
Prof. Littman: Nitromethane fuel has oxygen in it.
We looked at model of Model T engine.
For Next Time: Article about combustion chemistry posted on library site, Chapters 5 and 6 of ZAMM