Tuesday, November 25, 2008

Nature Abhores a Vacuum

I ordered a cheepo vacuum gauge from Ebay and it arrived yesterday. Hooked it up and I'm pulling about 25 hg at idle. Cool! I then went to my toolbox to put it away and layed it carefully atop my old vacuum gauge.....DOH!!!!! I sorta forgot that I already had one. I'll tell ya, old age ain't pretty and it ain't for sissies, either.

Several people have told me that I need a vacuum storage cannister. I looked around the shop for something to make it out of and spotted an old oil filter. I zipped off the top with a die grinder and soldered in a disc with a hole for the GM one way valve and grommet. I then soldered in a barb fitting for the hose going to the booster and, Voila, one Po' Boy freebee cannister. It's not as large as was recommended, but I think it'll be OK.

Sunday, November 23, 2008

Musings of an Uneducated Man

I barely escaped from high school. I took no algebra, no science classes, no foreign languages. Just shop, necessary classes for graduation and various yoyo courses. I may have ended up with a "C" average, but I doubt it. All of this in spite of the fact that I was tested in grade school, because of some unusual talents that I displayed, and was found to have a higher than average IQ.

I digress.

I was watching the Speed Channel this morning, eating my bowl of "Count Chocula" and listening to some guy telling me how performance can be improved by painting the underside of an intake manifold with white paint. According to the expert, white reflects heat and keeps the incoming air/fuel charge cooler, therefore, denser and as my Hawaiian buddy sez, "Mo bettah, brah."

Nice try.

Firstly, colors refect or absorb radiant heat, such as sunshine. Put a black object and a white object in the sun and it's easy to see that the white one will be demonstrably cooler than the dark one. Put the same objects in the oven, set it at 350 and check them in an hour. They will both be 350 degrees. In an engine, the friction, and combustion heat will transfer to all parts of the engine regardless of their color, just like the oven. Some areas will, naturally, be hotter than others. The exhaust manifolds will be much hotter than the intake, but not because of their respective colors. Additionally, colors do not exist in the absence of light. The inside of an engine is black. You can paint it pink if you like, but in the complete darkness of a lifter gallery, it is still black.

Maybe you know something that I don't, but for now, I believe this to be pseudo science, like concrete sucking the life out of a battery.

Saturday, November 8, 2008

Switch Panel

One of the big fears among BH riders is the frame breaking at the juncture of the rear down tubes. There is quite a distance between that point and the shock mounts. It is, certainly, not the best engineering. I figured that I might as well install gussets in that area while the bike is down. While cutting cardboard templates and trying to determine what size and shape to make them, I thought, "Why not make them large and use one of then as a switch panel." So I did. Now the left side cover will come off easily since it is no longer "wired" to the bike.
I also took some time to clean up the wiring a bit. There were still a few bad splices hiding under large wads of electrical tape. Some solder and shrink tubing did the trick. I tucked all the wiring up and as far foreward as it would go and now I have a nice shoebox sized area ahead of the battery to add a toolbox. I'll make a mockup from cardboard and then do some tin knockin'. I wish I had a sheetmetal brake, but a coupla pieces of angle iron clamped in the vise will do.

Thursday, November 6, 2008

The Better Mousetrap

The past few days have been spent installing the NOS Datsun brake booster on the bike. I had none of the brackets or any other hardware to make it work, so I improvised. I welded up a bracket to bolt to the side of the block in the holes provided by Chevy for the clutch linkage pivot ball. So far, so good. I rigged up an arm that pivots on the foot peg mount and engages the booster push rod. I then ran the clutch cable to the arm. Squeezing the lever pulls the arm and pushes the booster. A short. adjustable push rod goes from the opposite end of the booster to the throwout arm. I ran a vacuum hose to the booster and fired it up. It felt like the cable was welded to the frame. Two finger pull my butt!! Realizing that I may not be pulling enough vacuum, I went on my merry way to the junkyard in search of a vacuum pump. GM used them on a bunch of 4 cylinder stuff in the early 80s. I figured I'd pick up a couple just in case. Yeah, right. We have two large self serve yards nearby and not one lousey early 80s Citation/Sunbird/Cimmaron to be found. Too old for the regular yards and not old enough for the antique/oldies yard. So I went home and stared at it. I thought that something like a Harley mousetrap might be the answer, so I fabbed up this unlikely looking contraption. It pivots on the old swingarm hole. I went to the hardware store and grabbed two of the heaviest springs that they had. One end attaches to the lower end of the mousetrap and the other to a tab welded to the frame just under the seat. The springs are stretched tighter than a bowstring. A link attaches the mousetrap lever to the throwout arm. As it sits, the spring is over center and holds the mousetrap in the engaged position. As I pull the clutch lever, the contraption goes over center in the opposite direction and the tension of the springs assists the vacuum booster. The springs are a bit less powerful than the Belleville spring in the pressure plate, so when I ease off of the lever, the clutch re-engages. It seems to work very well. I still have some fine tuning to do. The hardware store springs look like they're stretched to the limit. I'm going to look for a more powerful spring to replace them. Maybe a hood hinge spring off of a large car or truck.
Of course, all of this didn't go without some hassle. The fuel pump had to be relocated. The On/Off/Reserve lever now pokes through the side cover. It looks better than what I had before. The hidden switch panel that I had, so cleverly, built also got the heave-ho. I need to find a new spot for them. I didn't like the key switch on the side cover because the leather fob rubbed on the paint and left a worn spot. I'll sit on my little thinking stool tomorow and stare at it some more