Drove Midlana for the first time in a long while – no issues with the alternator bracket. The drive reminded me about something that had been going on for awhile, and still is; when letting off the gas, engine speed hangs at about 1500-1600 rpm for 2-5 seconds before dropping to idle. I earlier thought that the idle control valve was suspect, but also mentioned that it has very low hours on it since being cleaned. Turns out that the throttle cable appears to be sticking a bit. Pushing the throttle to above idle speed, then lightly releasing it showed that the throttle doesn’t always close fully. I’d add a second throttle return spring, except this throttle body, with its helical return spring, doesn’t lend itself easily to that mod. Since replacing the throttle cable is a real bear (everything has to come out, seat belts, seats, middle channel cover), I rather first try a second spring.
As the new alternator bracket was being machined, it dawned on me that it’s been over 40 years since I last used a mill. To make it more entertaining was that as machining progressed, the part had fewer and fewer parallel faces on it to clamp on to. Thankfully, there were only a couple critical dimensions so I managed to not wreck it. The odd contours are dictated by what the bracket has to avoid on both the block and alternator. As you can see by the surface finish, a roughing cutter was used and I didn’t see any point in cleaning it up. The most egregious bits are the radiuses around the alternator mounting holes, which were done free hand – no CNC here, yet.
With that off the list, the next item is a new engine cover. As mentioned previously, it’s not just for looks. Wind comes up over the windscreen and pushes air immediately above the passenger compartment aft. That air has to be replaced, which comes from the area over the engine bay, and therein lies the potential problem. Say half way up a hill climb course, a fuel leak develops and lights off. Airflow will push the flames forward into the passenger compartment, which is too ugly to think about, so the engine bay needs to be covered. The new one may or may not use parts of the old, particularly the louver subassembly. The one nagging part is paint, which wouldn’t be an issue had non-metallic paint been used. I haven’t decided what to do; I’m concerned that if I attempt it, it won’t match at all. I’m almost tempted to go the other way, painting it flat black, but it obviously won’t match doing that either!
The thumbnail picture issue is still unresolved. It appears that Internet Explorer 11 doesn’t properly display thumbnail pictures here, but strangely, only pictures created after mid-February 2019 are affected, which makes no sense. More puzzling is that other browsers seem to have no problem with any of the pictures. I’ve tried everything I can think of to resolve it but have come up empty-handed. Since no one’s complaining, perhaps most people don’t use IE11, so I’m going to stop wasting time on it. Maybe IE or one of the apps has a problem that’ll eventually get fixed.
(After writing this, I went to check if these thumbnails appeared, and surprise, they all do, even the problem thumbnails from earlier. Sigh, apparently the solution is to just not worry about it, and it fixes itself!)
Okay, some actual Midlana content. As you may recall, there was some concern regarding how the alternator bracket seemed to flexing more than it should – there’s a reason for that. The fabricated alternator mounting bracket was caught cracking through, no doubt due to a combination of hardening after welding, and vibration. The question is, how to fix it?
The problem is that there is very little space to work in. I can’t just move the alternator away from the engine to free up space for a beefier bracket. The combination of belt routing, the proximity to the chassis, and where the available mounting holes really box in this one solution. While the cracks could be welded up, it’ll just happen again, so some thought has to go into this to do better for Version 2.0 (or whatever rev this is up to). One good thing is that with the mill on-hand, it opens up the option of fabricating a replacement from one chunk of steel (I don’t trust aluminum in this application due to its propensity for work-hardening). That avoids the issue with the heat-affected zones ending up hard and brittle.
Oh, and I signed up for the Virginia City Hillclimb. To be honest, I’m a little uncomfortable thinking about all that could go wrong – and the dire consequences. But then I remember that I’m the one steering, braking, and accelerating, so no one’s forcing me out of my comfort zone. It can simply be considered a car vacation, and a chance to get some great shots of Midlana on the shore of Lake Tahoe 🙂
In other news, I finally visited the Carlsbad Craftmanship Museum and got schooled on the use of a macro lens. For some reason I thought that my lens would be perfect for this, but it was just the opposite. Due to its zoom, I had to back up about 10 feet to get the subject entirely in the frame, then everything but one point was out of focus. The two pictures here are after I gave up and used my phone. Instead, just click on the above link and you can see better shots that anything I took. As an aside, this museum was founded by Joe Martin, past president of Sherline, maker of miniature lathes and mills. You really do need a macro lens though, to see the detail. The aircraft has every rivet and actuator in it. The crowning object in the museum is a 1/6 scale 1932 Duesenberg SJ that runs, on gas, and the transmission(!), steering, and suspension works, all made from scratch. It is truly a miniature car – which took 10’s of thousands of hours to complete.