Bubbles

Having cleaned the fuel tank and installed the fuel-level sender, the next step was to pressure test it. The tank has as a lot of TIG welding and if there’s a leak you want to find it before you install it and fill it with gas. I temporarily plumbed a Schrader value into the top left NPT port, a pressure gauge to into the top right NPT port and a  ½” NPT to -10 AN fitting with a cap in the bottom port. I pressurized the tank to 5 psi and went to dinner. When I returned the tank was down to 3 psi – I had a slow leak.

To find the leak, I mixed dish soap with a little water and brushed it on all of the seams. Fortunately, none of the tank seams leaked, but all of the NPT ports were leaking. I was surprised and how many bubbles a slow leak produced. I tightened the brass fittings as much as I dared, but they still leaked. While NPT threads are tapered, they don’t have a flare like you’d find in an AN fitting and they are often sealed with Teflon tape. However, Teflon tape isn’t compatible with fuel and if you’re not careful a piece might wind up in a fuel injector. Instead, I bought some Permatex Aviation Form-A-Gasket, applied it to the treads and no leaks! Next step is to install the tank.

Good Project for Hot Day

It was hot and humid which presented a good opportunity to remove all metal chips and dust from the fuel tank. The NPT openings were sealed with brass plugs and the fuel filler opening was sealed with this rubber end cap from Home Depot. The tank was filled with water via fuel-level sender opening and Connor was recruited help spill it out of the tank. The first rinse didn't result in any debris that I could see, but my OCD required that do it three times. Connor was having fun and he demanded that we do it a fourth time, so it's one clean tank.

When then tank was dry, I poured several cups of acetone into the tank and sloshed it around on all sides to remove any residue. 

The fuel-level sender provided in the kit is very nice. It is customized to take the unique shape of the tank into account and it measures capacitance so it has no  moving parts. The sender was mounted with five 10-24 bolts, #10 washers and the supplied cork gasket. Loctite 442 (aka blue Loctite), which is compatible with fuel, was applied to the threads.

Vacation and RPVs

I’ve been on vacation and I haven’t had any time to work on the car. However, I have been doing lots of research and ordering things. This of course causes a debate with my son when I try to get him off the iPad. He just doesn't see the difference between "research" and playing games.

Everything in the SL-C is low and the brake master cylinders are no exception. They are mounted below the brake calipers and gravity will cause brake fluid from the calipers to drain back into the master cylinder which causes excessive caliper piston retraction which results in a longer brake pedal stroke. To solve this problem, a residual pressure valve (RPV) is installed. A 2 psi RPV is firm enough to prevent fluid from flowing back but not so firm as to extend the caliper piston which would cause the brakes to drag. Since there are two master cylinders (front and rear) two valves are needed. The kit came with valves, but some builders have had issues with them leaking so I upgraded them to Wilwoods.

Fuel Tank: Part 1

I finally got around to removing the cage, interior tub and back panel to get access to the fuel tank. As with many Superlite parts, it's custom made and beautifully TIG welded. The pipe passing through the middle of the tank (you can see all of the way through it in the first picture) provides the straightest possible path for the shift cables... it's a mid-engine car and the drivetrain is behind the driver. It angles downwards from the driver side towards the passenger side.

The first step was to tap five 10-24 holes in the fuel level sender flange... and then start ordering lots of parts to start connecting things.

Seat Brackets

I wanted to see what it feels like to sit in the car so I installed the seat brackets. I'm likely going to upgrade to Tillet carbon fiber T5s in the future, but these will work for now. Comments at bottom of each picture.

Body Dolly

I removed the body today and built a dolly so that I can move it around. I was going to stand the sections up to save space, but I didn't want to store it in a way that might cause the body to deform. I also love looking at the car and I wanted it around to inspire me, so I built a whole-car dolly out of 2x 4's and 3/4" plywood sitting on six lockable caster. It raises the body a bit so it doesn't look quite as bad ass...

Note that I ran out of time and the nose and tail aren't sitting right... I'll fix that later. Can you find the dog in the picture below?

It's Here!

My car was delivered last week... about as good as Xmas morning when I got a Six Million Dollar Man action figure, a Guns of Navarone mountain and a bunch of military/automotive models. Reflecting on it, that’s a glorified doll, a multi-story doll house and models that required glue that causes brain damage if sniffed… what the hell were my parents thinking?

In any event, there was lots of tape residue on the car. The more options, the more residue. I did a bake off between Goo Gone, Goof Off and WD-40. Goof Off worked the best.

Father / Son Boondoogle

My son had vacation this week, my daughter had school and my wife was in Europe. What to do with a 10-year old? Take him to California to spend some time with the grandparents. For some reason I couldn't find a direct flight from Boston to San Francisco so I had spend a night in Detroit on the way there... so we went to the Henry Ford Museum.. and along the way we somehow stumbled into Superlite Cars / RCR...

MoTec Quality

The MoTec ECU, GPS transceiver and digital display were delivered today. The quality of the case is outstanding not to mention the display itself. MoTec appears to have their act together with respect to software and product modules. Many of the features in their embedded devices are activated via software keys. I assume the branded USB stick in the foreground does exactly that. It will be quite some time before I know for certain if MoTec is as good as their reputation, but so far I'm impressed.