 11. CAD drawing of exhaust...  11. CAD drawing of exhaust system from Patten Cycles. |
 12. Unpolished versus polished...  12. Unpolished versus polished rear pipes. |
 13. Polishing exhaust and...  13. Polishing exhaust and making a mess of the workshop. |
 14. Full exhaust system v...  14. Full exhaust system view. |
 15. Gas tank vent and overflow...  15. Gas tank vent and overflow hoses. |
 16. Fuel pressure sending...  16. Fuel pressure sending unit. |
 17. Main fuel line along rear...  17. Main fuel line along rear of frame. |
RoutingChoices: The first choice you will make is whether you want an undercar or side-exhaust system. The latter avoids much of the clearance issues and can be simpler to connect to the exhaust header or manifold. If going under the car, you'll have to find the straightest route that will clear the major components and allow for enough space to avoid exhaust heat in the transmission tunnel, under the floor, and the gas tank.For our project, since the '63 didn't have side exhaust as an option, we wanted to retain the undercar location. We also, however, wanted to include a C5/C6 styling element, as we had with our '62, by routing the exhaust tips through a cutout in the center of the rear valance. The valance had to be cut to the height and width needed to clear the four Corsa exhaust tips, which are shown in Photo 10.
Design: We went a little further than usual for our project by having our initial design converted into a CAD program. We worked with Ken Kleitz of Patten Cycles on the design, and they bent the system on their mandrel bender equipment. This was quite an involved process because it required taking precise measurements to attain the angles needed to mate with the collectors, clear the transmission, hit the center of the transmission crossmember openings, clear the floor and differential, and end up with the exhaust tips exiting where we wanted. Photo 11 shows the CAD drawing made by Patten Cycles, which was used as the guide for bending the pipes.
Polishing: As with everything else on this project, there were many hours spent in grinding welds, smoothing all the components, and polishing. While the smaller pieces can be done using a stationary buffer, we found the longer pipes had to be prepared by hand. After removing any marks left from the bending equipment, we began by using the Dynafile with a Trizact belt and then a random orbit sander with finer and finer grits of sandpaper. Then it was into the hand work, using strips of sandpaper from a 220 through 2,000 grit to remove any scratches and prepare for polishing. Next, we used the Porta-Cable random orbit buffer and various polishing compounds for the final finish. Photo 12 shows a comparison of the pipes before and after polishing. Photo 13 shows the polishing by hand, and the small mountain of used sandpaper and grime on the floor. Polishing the mufflers was a bit easier as they are round, and we were able to make a jig to hold them in our wood lathe. That allowed us to turn the mufflers to grind the welds and smooth the surface to prepare for polishing.
Finished System: Photo 14 shows what our finished system looks like from a rear overhead shot. Since we don't have the car ready to run yet, we don't know what it will sound like, but it should be great.
Fuel System-Key Design Factors:The key components in the fuel system are the fuel tank, fuel pump, fuel supply and return lines, fuel pressure regulating, fuel filtering, and fuel level monitoring.Fuel Tank: For the LS engine, most folks use a fuel tank with an in-tank pump. We used the stainless tank from Rock Valley. We did make a few design changes, such as having the outlet and return lines located at the top of the tank rather than at the bottom. This kept the bottom of the tank clean and also made it easier to route the supply and return lines. The tank has an in-tank LS fuel pump. Photo 15 shows a rear view of the tank, the vent, and overflow lines.Tank venting can use an original vented-style gas cap or use the vent/check valve setup supplied with the tank. Either one should work fine, but we went with the supplied check valve and used a locking nonvented gas cap. Rather than running the vent hose over the tank, we chose to run it into the filler boot that you can see in the photo. You can see the drain line from the boot, which also uses a braided hose. To retain its shape, a 5?16-inch fuel line was inserted into the braided hose and then bent to shape. It's held in place by a fitting bolted to the rear crossmember.