| A fellow
customizer, Kartsa, asked me to race against his 1949 Roadmaster at the
Street Slide drags,
and I accepted the challenge. Just for fun, of course. His Roadie is
retrofitted with the ever popular SBC
350/TH350 combo, and he's running the same 2.73 rear gear as I
do. I would quess our cars weigh as much, too, so we already knew the
winner. We were both busy to attend other happenings the same day, so
we only had a chance to have one pass at the strip. We arranged in the
lineup so that we could race against one another. Oh boy, what a
thrill ! The engine was still under run-in, and I didn't have the guts to rev it higher than 3500-3700 RPM between shifts. My first gear is really too tall, and my starting RPM was too slow, so I failed launching the car. If you remember, I set up some performance goals in my May 2002 entry, in particular: It will pass 1/4 mile in less than 20 seconds, and have a trap speed of over 60 mph. Well, mission accomplished, as I ran 19.53 sec at 72 mph. Kartsa's '49 ran 17.62 at 80 mph. With some training, I might reach high 18's. Anyway, I was a happy man! |
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I also set another goal 3 years ago: Highway Mileage shall not be worse than 16 mpg (about 15 L/100 km). According to my calculations over the last few hundred miles of highway driving at 60 to 70 mph, and one cruising night at the Helsinki city, the fuel mileage has averaged 18 mpg (13 L / 100 km), which is very nice. A fellow with an original 1948 Roadmaster with a stick shift, says he can't get better than 12-13 mpg (18-20 L / 100 km). Even my Cobra, also with a 2.73 gear, but being 1600 lbs lighter, is thirstier at 17.7 mpg (13.3 L / 100 km), in pure highway cruise! Not bad for a 1940's technology, not bad at all. I would address this "fuel economy" to the tall rear gear, and the improved efficiency of the engine. |
 The original 6-volt starter has been giving me a hard
time. The symptoms were like a bad starter drive: many times when I
started, I just heard the starter rev up high, sometimes it cranked the
engine a couple of turns, and then slipped, sometimes it cranked fine.
I thought the culprit was a bad starter drive. I got a new (yes, NEW)
starter drive from eBay and installed it, to no avail.I was using the original 6-volt starter with 12 volts (I never tried it with 6 volts). During the initial build-up, I replaced two out of three bushings (don't remember which ones) and brushes, and trued the contact surfaces inside the solenoid. I also adjusted the pinion travel to specs by adjusting the solenoid plunger stud. During the initial startups, the starter cranked just fine, over and over. Then, all of a sudden, it began to miss, and the problem seemed to get worse. There is no way to adjust the contact pattern between the pinion and flywheel teeth, because of the starter mounting system. The starter acted like the solenoid was closing the main contacts too early. But like I said, it had been adjusted to specs. I asked for help at various web forums like the AACA BCA forum and Buicks.net, and got some good advice, like missing gear teeth on the flywheel (they were fine when I assembled the engine), or a burnt "holding coil" in the solenoid. All of these made sense to me. Someone suggested to try a 12-volt solenoid on the 6-volt starter, as that had worked for him in several cases. That's what I did. I was able to get a 12-volt solenoid from a 1953 Buick, and it seems to work. The starter may still miss occasionally, maybe 1 out of 20 starts, but I can live with it. It could be that the gear teeth have been damaged from the repeated misses, who knows. My theory is that, with 12 volts, the 6-volt solenoid acts too fast, closing the contacts before the starter pinion has engaged properly. I was thinking if I could have run a ballast resistor in series with the solenoid wire, effectively dropping the 12 volts to 6 volts for the solenoid (for not to burn it, and to slow it down). However this is not possible. In the picture above you'll see an internal relay that connects the actual hot wire from the battery terminal to the solenoid, and it cannot be by-passed. Running a ballast would only drop the voltage to this relay, but the solenoid would still get full 12 volts. |
 This is the 12-volt solenoid. It bolts on the 6-volt starter without modifications, although it kicks the pinion as deep as it can go before it closes the contacts (contrary to the 6-volt solenoid, the plunger depth is non-adjustable). The mounting holes were elongated but I filed them a bit longer to gain some adjustability. Moreover, the battery cable studs are of larger diameter. If I had the energy, I would still try the 6-volt solenoid, but this time I would adjust the plunger depth so that it would kick the pinion as far as it goes before closing the contacts. The 6-volt solenoid grounds through the voltage regulator. When the engine is running and the generator is charging, that ground switches to +6 volts, preventing accidental cranking while the engine is running, should the carb switch fail. The 12-volt solenoid grounds itself through the body, so there isn't any backup system. Actually I had already lost that feature when I converted the whole system to 12 volts with an alternator, and simply ran a wire from the solenoid terminal to the ground. Now it's 1 wire less. |