Since we wanted to maintain as much recognition as possible with the new Z06, we chose to use the OEM dry-sump reservoir. It also has provisions for the dipstick and tank vent lines to the engine. However, the stock tank is too tall to fit within the C2 engine compartment, and so we contacted Line Precision who makes the OEM tank. working with them, we were able to retain the original upper and lower cast portions, along with a new center section that was shorter and wider in order to maintain the original 10.5-quart capacity of the stock tank.
In researching the details of the dry-sump setup, we found quite a few details on the stock system. There are two fittings on top of the tank. The rear fitting on the reservoir runs to the "dirty-air" connection on the front passenger side of the engine and to the PCV. The forward fitting runs to the clean-air fitting ahead of the throttle body. The tank contains a volume of 10.5 quarts, which is the minimum required to run an 8-quart service fill with the LS7 engine. When 8 quarts are added to the tank, 1.2 quarts fill the lines and cored passage in the oil pan, leaving 6.8 quarts of oil in the tank. The remaining volume of the tank is intended to provide for oil conditioning, de-aeration, and a fresh-air provision to prevent sludging and PCV separation. If you use an aftermarket tank, it's important that you create these provisions for crankcase pressure equalization and PCV system flow. The LS7 uses two oil pumps: the scavenge pump pumps 25-percent more volume into the tank than the supply pump draws out. This extra volume is air, which will pressurize the tank if you don't have a way to equalize the pressure with the crankcase. It will also draw down the pressure on the crankcase to unacceptable levels, so there should be a line connecting the tank to the crankcase for pressure equalization. It's also recommended that you provide fresh air to the tank and draw foul air off the crankcase through the PCV system.
The oil lines from the engine to the oil reservoir are unique fittings. If you can run the OEM lines, these will work fine. If not, or if you are using an aftermarket reservoir, such as that from Peterson Systems, you can get adaptors that convert the lines to an AN12 fitting. There are several sources for these fittings, such as Street & Performance.
To mount the tank, two lower brackets were made that fit into tabs welded to the frame and one upper bracket that mounts to the firewall.
To gain space for the oil reservoir, which was placed in the rear of the passenger side of the engine compartment, the battery location had to be moved. In some cars, the battery could be placed in the trunk area (if we had one!) or the rear of the passenger compartment. However, we didn't like the idea of a battery in that location or running the cables that far from the engine. We decided to fabricate a new battery mount on the driver-side framerails just behind the inner fender panel. For access to the battery, a panel originally used on A/C-equipped, big-block midyears was used in the rear of the inner fender panel.
You may be able to use the stock exhaust manifolds. They do have a unique outlet though, which makes making the rest of the system more difficult. You may also run into clearance issues with your frame or engine mounts. Street & Performance made a set of headers for us with larger primary tubes, a flange to match the LS7 port shape and with the necessary clearance. Stainless collectors were used, which will be mated to the rest of the exhaust system that we will cover in a future installment.