How To Build A Bulletproof Oiling System - How It Works
Moroso Performance Products explains how to build a bulletproof oiling system for max reliability and horsepower.
From the May, 2012 issue of Chevy High Performance
By Stephen Kim
If you’re Bill Gates or that kid who owns Facebook, you can probably spare a million bucks more easily than a regular working man can cough up a thousand dollars. That’s just the way things go, so there’s no sense in being a hater. For car guys, this means that regardless of your budget, whether you have a $3,000 motor or a $23,000 motor in your street machine, you probably bought yourself as much horsepower as you could afford. Given all the cash that hot rodders are willing to dump into an engine without thinking twice, it’s somewhat peculiar that the oiling system is often an afterthought. Not only does the slick stuff touch just about every moving part in an engine, but even if you lose oil pressure for just the briefest of moments, the entire lump can go kaput. That’s not much breathing room, and considering all the money that’s at stake, perhaps it’s time to take oiling systems a bit more seriously.
Whenever the driver is having fun, the oiling system isn’t. Every time you entertain yourself by turning the wheel, stomping the brake pedal, or popping the transbrake, g-forces try their hardest to uncover the oil pump pickup. Fortunately, a little ingenuity goes a long way in fighting the forces of physics. Oil pans with kicked-out sumps, trapdoors, and baffles go a long way in keeping the oil where it should be, but there’s far more to it than that. Accumulator systems store an emergency supply of oil to save a motor if starvation becomes an issue, and the ultimate in oil control is a dry-sump system. Granted these are well-known facts, but as oiling system technology continues to rapidly advance, plenty of new innovations are out there to help keep an engine lubed and happy. Furthermore, proper oil management isn’t just about component longevity. Plenty of horsepower can be had by optimizing oil flow. To get educated on the latest trends in oiling technology, we contacted Thor Schroeder of Moroso Performance Products. The company has been on top of the oiling game for more than four decades, and proper oil control is far more involved than slapping on a pan and calling it a day.
Once an oil pan is bolted to an engine, it’s impossible to see what’s going on inside the crankcase. Consequently, during the design process we experiment with transparent oil pans, high-speed cameras, and strobe lights to try to document the affects of windage firsthand. Over the course of a year, Moroso performs hundreds and hundreds of dyno pulls using our in-house DTS dyno. During the development process of a new oil pan design, Moroso builds versions with transparent windows to analyze how different features affect windage and overall oil control. This is done so that when the oil pan hits the marketplace it will be a top performer. At Moroso, our oil pans are built using brand-new oil pan cores. We use a laser cutter to cut each sump so that the tolerances are the same from oil pan to oil pan. Conversely, cutting each oil pan core by hand leads to variations from core to core when matching up the fabricated sump with the oil pan core itself. All of our oil pans are designed using three-dimensional software for perfect fitment.
Windage is a term that gets thrown around a lot, but it’s not always clearly defined. For instance, the windage tray has been broadened to encompass a couple different features in recent years. In many cases, the sheetmetal plate that goes over the opening of the sump, where it meets the body of the oil pan, has been called a windage tray. This is actually the anti-slosh baffle, which is designed to keep the oil contained in the sump so that it does not get back into the rotating assembly. The windage tray itself is the screen or louvered piece that is either mounted directly to the main caps of the engine, or in the oil pan itself, and usually has an integrated crank scraper. At Moroso, our oil pan and windage tray designs live and die by our in-house dyno, track testing, and our network of top engine builders and racers who we use to test our products. We feel windage trays are important in a high-performance oiling system. Some engines and oil pans can benefit more from windage trays than others. Engines that are static and employ big box oil pans—which keeps the oil away from the crank—and have a conservative rod and stroke combination are not as prone to windage. The same goes for engines that are operated in an rpm range that is less than 5,500. Conversely, a long-stroke, high-rpm engine with a small oil pan that is put through acceleration, deceleration, right turns, left turns, and quick up and down movements is more prone to windage. We have seen and heard of windage trays freeing up to 5 percent more horsepower on these types of engines. Also, a windage tray can help with oil temperature and pressure. How? By keeping oil off the crank so that it does not froth the oil, and put extra heat into it.
With the growing popularity of Pro Touring muscle cars and open track events, it’s not that uncommon to run into a racer in the pits who has suffered some kind of oil starvation issue. Several techniques can be used when designing an oil pan to address this. The oil pans that we produce for road race and autocross applications have a sump that is shaped like an upside down “T”. This shape serves many functions. It allows extra oil capacity without the sump being too deep, since road race and autocross cars like being lower to the ground for handling and braking purposes. Inside a proper road race oil pan there is trapdoor baffling, which are hinged pieces of sheetmetal that open up to a 45-degree angle during acceleration, cornering, and, in some cases, braking. These trapdoor baffles are attached to sheetmetal dividers. As a result, during hard acceleration a trapdoor baffle will swing open and release a pocket of oil that has been held back by the divider. The released oil then feeds the oil pump pickup without a disruption in oil flow. The sides of the sumps that tee out are called wings, and they also hold pockets of oil that are held by trapdoor baffling in each side. When a car that is equipped with the road race oil pan takes hard right or left turns, the trapdoor on the opposite side opens up and releases oil to feed the oil pump pickup. When the trapdoor closes, the reserve of oil builds back up to be ready for the next time that it is needed. For 2011, Moroso introduced a line of road race oil pans for C3 and C4 Corvettes, as well as other low ground clearance applications. This the first line of road race oil pans on the market that will clear a 4.125-inch stroke with most steel rods. In the coming months, Moroso Performance Products will be expanding our line of multi-baffled oil pans.
As engine combinations and racing conditions become more extreme, racers often step up to a dry-sump oiling system in both drag and road race applications. That’s because they are the safest and most dependable oiling systems available. They’re popular in any class of racing where the rules allow them, especially where low chassis height is important for good handling. Horsepower gain is maximized in a dry-sump system, because there is virtually no oil in the pan and no internal pump, allowing the windage tray or screen to run the full length of the pan. Other advantages of a dry-sump system include a remotely mounted oil tank for increased capacity, the ability to easily add remote oil coolers, more consistent oil pressure, adjustable oil pressure, improved scavenging, and increased ring seal due to greater oil pan vacuum. A dry-sump oiling system consists of the dry-sump pump itself, which can have anywhere between one to six stages. The stage designation refers to how many scavenge and pressure sections the pump has. For example, a four-stage oiling system would have three oil pickups in the oil pan itself. Each one of these pickups would be plumbed to the three scavenge sections of the oil pump. With this type of oiling system, a full-length windage tray can be used inside of the oil pan and the oil can be stored outside of the oil pan in a baffled dry-sump tank.
Can a wet sump work as well as a dry-sump system? Yes and no. Even though Moroso sells three different series of dry-sump pumps, production and custom dry-sump oil pans, and dry-sump tanks, certain applications are better suited to a wet sump oiling system. On street applications, all but the most exotic and high-performance street cars are better suited to a wet sump system. This is because a dry-sump system adds complexity, cost, more maintenance, and a user that has to be more mindful of what the system is doing. Additionally, in many racing classes dry-sump systems are simply not allowed.
Whether you have a street car, or you’re racing in a class that prohibits a dry-sump oiling system, there are several ways to enhance the performance of a wet sump system. A good place to start is with an oil pan with trapdoor assemblies that keep oil in the pump pickup area during acceleration, braking, and cornering. Likewise, Moroso offers billet aluminum wet sump oil pumps for small- and big-block Chevy engines. These pumps have a mounting area that’s three times larger than a stock pump to prevent braking. They also weigh a pound less, have larger pickups and inlet areas to prevent cavitation, and thrust bearing assemblies that increase housing and gear life due to improved driveshaft axial forces on the drive gear. Lastly, plumbing an oil accumulator into a wet sump system helps ensure a steady flow of oil in the event that the pickup is ever uncovered.
The purpose of a vacuum pump is to remove air, blow-by gases, and other contaminants from the crankcase of an engine. The vacuum pump’s ability to remove the air in the crankcase results in overall engine vacuum. This vacuum increases horsepower by allowing the use of low tension compression and oil control rings. The combination of low-tension rings and crankcase vacuum reduces frictional horsepower losses, blow-by, intake charge contamination, and the potential for detonation. Moroso’s purpose-built racing vacuum pumps offer all these advantages and more, whether the engine at hand is a naturally aspirated small-block or a nitrous-equipped Pro Mod. The components required to install a vacuum pump system are the vacuum pump itself, a mounting bracket, a vacuum pump pulley, a crankshaft drive pulley, a drivebelt, a vacuum pump line kit, a regulator, and a breather tank.
Many late-models develop oil control issues with their PCV systems, but fortunately, there’s an easy remedy for this problem. From the factory, excess crankcase vapor and residual oil are vented back into the intake manifold. This is compounded by today’s ethanol-enriched fuels. The oil mist can cause detonation, and leaves deposits on the intake tract and the valves. To fix this issue, Moroso has developed air-oil separators that plumb into the PCV system and capture this oil mist. The oil mist enters the separator, where the oil sinks to the bottom and the rest of the gases are plumbed back into the intake. The oil can then be drained from the separator as necessary. Some of these air-oil separators are generic, but Moroso now offers vehicle-specific kits for cars like the fifth-gen Camaro. They are available in two sizes and feature billet aluminum bodies, stainless steel mounting brackets, inlet and outlet fittings, and high-quality rubber hose for plumbing it into the PCV system.
For cars with wet sump oiling systems, adding an oil accumulator is a great way to reduce the potential for oil starvation. An accumulator is essentially a hydraulic cylinder with billet aluminum endcaps that stores oil under pressure. It releases an instantaneous supply of oil when the oil pressure drops below a safe level, and it can also be used to pre-lube the engine before startup. The accumulator can be tapped into the return line of an oil cooler, directly into the oil valley in the block, or through a sandwich adapter that mounts between the spin-on oil filter and the block. When the engine is running, oil pressure forces a supply of reserve oil into the accumulator and compresses the air ahead of it inside the hydraulic cylinder. If the engine’s oil pressure should suddenly drop because of hard acceleration, severe cornering, or hard braking, the air pressure immediately sends oil out of the accumulator and into the main galleries. When the severe conditions subside and the oil pump is once again primed, the oil pressure forces oil back into the accumulator where it is ready for the next potential emergency.
For an accumulator to function properly, it needs a valve assembly so each Moroso accumulator comes with a manual ball valve. The valve has to be manually opened by hand before starting the car to pre-lube the engine and manually closed before turning the engine off. As an option, Moroso offers solenoid pressure valve kits in oil pressure ranges of 15-24, 35-40, and 55-60 psi. These kits release just enough oil to prevent starvation, which allows for quicker filling and discharging. They work very well in remote mount situations where accessing a manual valve is not an option.
Accumulators aren’t just for road racing. They are very effective in drag racing applications as well. Many independent tests have shown that over 85 percent of engine wear is caused by starting an engine, and these dry starts cause premature engine wear. An accumulator is beneficial for pre-lubing the engine before start-up, especially since drag cars tend to sit for a long time between races and between rounds. Also, during hard acceleration, an accumulator helps guard against oil pressure fluctuations. For drag cars that accelerate very hard, the oil can rush to the front of the pan during shut down or if the driver needs to brake. Accumulators provide a safeguard of oil in reserve during these situations. Drag racers have also used accumulators to free up horsepower by running less oil in the oil pan, or using them in classes that have oil pan design limitations. CHP