The advantages of a dry sump oil system versus an OEM wet sump lubrication setup are significant. They include improving power through vastly reduced windage, the elimination of oil starvation during hard acceleration, braking, or cornering, allowing for a lower engine placement, and providing a regulated flow of cool, clean oil to reduce engine wear. Another key benefit is the ability to set up system optimized for any given engine and application, and that’s what we’ll delve into here.
For input on the matter, we’ve turned to John Schwarz, President of Aviaid Oil Systems in Chatsworth, California. The company is credited with introducing dry sump technology to commercial motorsports in the late 1960s and has built systems for a wide variety of motorsports applications across the spectrum. Schwarz has headed the company since the late 1990s.
Dry-Sump System Variables
As you might suspect, there are many variables involved in creating the perfect dry-sump system for a given engine combination. The “heart” of the system is the pump itself, which can range from a simple single-stage pump that only handles pan scavenging all the way to complex nine-stage setups with extra sections for power steering and fuel delivery. By far, most systems are three- or four-stage setups with one pressure section and the rest configured to evacuate the pan.
There are a number of variables to consider, the first being the individual pump size. Aviaid offers no less than five different-width sections, ranging from 1 inch-thick to 2 inches-thick in .250-inch increments. Obviously, the larger the section thickness, the higher the throughput. Then there is the type of pump section to consider. In addition to its popular gear-type Series 1 pumps, Aviaid offers a Series 2 design with Roots-type rotors instead of gears in all the scavenge sections. Besides capacity, these different styles have different efficiency ranges that can be tailored to the specific combination.
Pump Mounting and Drives
The pumps themselves are driven through various means, including Gilmer and HTD belts with crankshaft/damper-mounted pulleys, as well as cam drives and third-party accessory drives, like Alston’s CDS system. Of course, the act of driving the pump costs engine power, so ideally you’d want to find the proper balance of sections/stages to get the job done without overburdening the engine.
“There are many variables to contend with, including the engine’s displacement and scope of modifications, intended RPM range, type of competition, tank capacity, and more,” says Schwarz. “Based on many, many years of experience, we have developed baseline packages for a number of the more popular engine and application combinations that can be ordered with a single part number for convenience. But with others, it’s simply a matter of analyzing everything and coming up with an optimized package. To this extent, we have worked with many engine builders to develop packages for their popular builds.”
The mounting location of the pumps is an important consideration. As such, Aviaid offers both left and right-side brackets for a number of applications. For the Chevy LS engine, Aviaid has both cylinder head and block mounts, for both the right and left side, as well as one that utilizes the factory air conditioning bosses. Aviaid’s LT offerings also include both left and right-hand mounts. With dozens and dozens of dedicated mounting brackets and blades, plus plenty of “universal” designs, Aviaid can mount a pump on virtually any 4-, 6-, 8-, 10-, or 12-cylinder engine.
Sucking The Pan Dry
Then there are the oil pan options. Since dry-sump systems require the use of a special oil pan, it only stands to reason that Aviaid offers a variety of them. Just like standard wet-sump pans, dry-sump pans are manufactured from billet aluminum, cast aluminum, and fabricated aluminum, as well as fabricated steel. Like the rest of the components, there are a number of variables in each pan design. These include the number of pick-up points and their locations for scavenging, sump dimensions, weight, durability, and cost.
As you might imagine, billet aluminum pans are the most expensive of the lot, given material cost and manufacturing requirements. Advantages include an ultra-low profile, with as little as 1.75-inch pan depth for LS, Coyote, and Chrysler Gen-II Hemi models, and virtual indestructibility. On the other end of the spectrum is fabricated steel pans, which Aviaid has been building for over 60 years. They are by far the most popular and represent the best value. Over the years, literally dozens of special designs have been developed to handle myriad applications. Aviaid also modifies some factory pans in certain cases.
Dry Sump Tanks
Sump tanks are an integral part of any dry-sump system. Like every other component, Aviaid manufactures them in multiple sizes and capacities. The three most-popular diameters are 6.0 inches, 7.5 inches, and 9.0 inches, with varying heights to provide capacities from one through three gallons. According to Schwarz, “Two gallon tanks are a minimum for most applications, but for more radical big-inch engines we recommend more. A larger capacity tank can contribute to a cooler oil supply, but you have the penalty of added weight. Of course, the needs of a drag racer are different than that of an endurance road racer or off-roaders.”
The dry-sump oil tanks also perform a valuable function in removing any aeration (tiny air bubbles trapped in the oil that are a result of the oil being “whipped” by the rotating crankshaft assembly) for the oil feed. Besides the inherent benefit of the separate oil tank, special baffles are employed to “settle” the oil in its transition. It is also imperative to vent the tank.
Adjustable Oil Pressure
The ability to control oil pressure externally is another benefit of a dry sump system. While you might be able to go up or down 10 psi in a standard oil pump by changing the bypass spring, a dry-sump system offers much finer adjustment to dial in the engine. Depending on the setup, this can be achieved at the pump, through the use of a remote regulator, or with a combination regulator/filter mount. However, It is the volume of lubricant that’s most critical — which is addressed by the size of the pump section.
Of course, the act of routing the oil to the dry sump system begins and ends with special block adapters. Aviaid has CNC-machined billet aluminum adapters for this purpose, and also offers a cast-aluminum Traco-style adapter for use in vintage applications. Given the variations in mounting various system components. Aviaid does not provide the required “plumbing” — that falls into the builder’s wheelhouse — but Aviaid does offer a variety of fittings and braided stainless steel hose as an add-on. The company also inventories the appropriate coolers and filters for customer convenience.
While Aviaid has developed no less than nine dry-sump system packages for the LS engine, plus right and left-side systems for the LT in addition to other popular applications, the company’s strong suit is configuring an efficient lubrication system for virtually any engine. So whether you are looking for a pre-engineered solution, or an entirely custom dry-sump system for your setup, Aviaid should be able to provide you with what you need.
Ed. Note: This article was provided by the manufacturer, but contains sound information regarding the design and implementation of a dry-sump oiling system.