Wet & Dry Sump Oiling Systems
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Wet & Dry Sump Oiling Systems Oiling Systems Oiling Choosing the Right System for the Right Job By Larry Carley, Technical Editor [email protected] f you are building a customer’s classes to keep costs down. the pickup starts to suck air, which “dream engine” what type of oiling Regardless of what type of oiling leads to a sudden and precarious drop Isystem should you use? The answer system you and your customer in oil pressure. If the situation isn’t to that question will depend on the ultimately decide upon, don’t cheap remedied almost immediately, it can application (street, drag, circle track, out to save money. A customer who be bad news for the rod and main road race, off-road or marine), engine has already spent a ton of money bearings. Consequently, it’s essential RPM and how much your customer for block work, pistons, rods, heads, to make sure the oiling system’s is willing to invest in a lubrication valve work, a forged crank or stroker capabilities match the application. system. crank, balancing, a hot cam, lifters Your choices may also be limited and valvetrain may feel like he’s Street Performance by track rules that restrict what spent enough already and might try Recommendations type of oil pump or oiling system is to pinch pennies when it comes to Street performance is normally allowed. A lot of dirt tracks and road the oiling system. Bad mistake! The not that demanding, but it can be courses don’t allow dry sump oiling oiling system is not an afterthought. the equivalent of drag racing or systems in entry level and stock It’s the key to protecting all of these road racing depending on what’s other components and keeping them happening at any given time. Most lubricated. stock oil pans can handle “normal” A stock wet sump oiling system acceleration, deceleration and with a stock oil pump and stock oil cornering forces without starving the pan are usually adequate for everyday pump. But as G-forces in any direction driving, but not much more. If an go up, so do the changes of sucking air engine is being built to rev higher, into the oil pump’s pickup. make more power and accelerate a A recommended upgrade for a vehicle faster, the stock oiling system wet sump system would be to replace may run out of pressure at the worst the stock oil pan with a good quality possible moment. aftermarket performance oil pan. The same risks hold true when Performance pans have better baffling brakes are modified to increase to reduce oil slosh so the pickup stopping power, when chassis are will stay submerged in oil. A deeper modified to enhance cornering agility sump also helps (assuming there is and the stock tires are replaced with clearance for such) and increases total soft race compound rubber. As fore, aft oil capacity (which helps the oil run and lateral G-forces increase, oil slosh cooler and last longer). inside the pan may be so severe that Watch out for cheap knock-off oil pans that don’t have proper baffling Dry sump systems with multi-stage and are made of thinner gauge steel. suction pumps pull oil out of the They may not provide the oil control crankcase, separate oil and air and you need, and if made to poor quality maintain a steady oil supply to the standards may be hard to seal. engine. Installation may also be an issue on some applications due to bolt hole 36 June 2016 | EngineBuilder misalignment. can usually provide adequate oil Cast aluminum pans with fins can pressure for an engine that won’t turn provide some additional cooling benefits more than 6,500 RPM – provided it and will enhance the appearance of the is a low mileage pump with normal engine. Just remember that aluminum is clearances, not an old high mileage brittle and may crack and leak if you hit pump with lots of internal wear. So at something, whereas a steel pan will dent. the very least, a new oil pump is always For more serious street performance recommended. applications, one aftermarket oil pan The output of many stock spur gear manufacturer recommends replacing style pumps starts to flat line around Aftermarket performance oil pumps come the stock oil pan with a road race pan. 6,000 RPM. As the gears spin faster and in different designs and configurations for A road race pan is designed with baffles faster, oil flow into the spaces between different applications (courtesy of Schumann and trap doors to limit oil movement in the teeth can’t keep up and the pump Sales & Service) all four directions. starts to cavitate. Gerotor pumps are Another must upgrade for every wet a little better in this respect and will causes a drop in oil pressure. Thinner sump system is some type of windage handle somewhat higher RPMs before oils such as 5W-20 and 0W-20 resist tray or scraper to keep oil away from the they start to flat line. But eventually, all cavitation better than thicker oils such crankshaft. A windage tray will reduce stock pumps reach a limit. as 15W-40 because the lower viscosity drag on the crankshaft and oil aeration, Cavitation is the formation of little allows the oil to flow more easily both of which are good for making more bubbles on the trailing edges of the gear through the pump at higher engine power and improving lubrication. teeth inside the pump. Cavitation is speeds. As for the oil pump, a stock pump bad news because it aerates the oil and If a stock oil pump can’t match the circle 37 for more information EngineBuilderMag.com 37 Oiling Systems engine’s RPM potential, it needs to be unique gear designs, such as helical pump’s load on the engine. Changing upgraded to some type of aftermarket gears rather than straight cut spur gears. the pressure relief springs in the pump performance pump. There are many Slanting the gear teeth improves flow 5 can fine tune the pump’s output to better different pump designs to choose to 10% according to one manufacturer, match the application. from, with various design features and while reducing pressure fluctuations at High volume oil pumps with longer benefits. The key difference is that a the pump’s outlet port. That, in turn, can (taller) gears are a popular upgrade to performance oil pump is engineered to reduce ignition timing changes (spark increase oil flow (typically 15% or more) flow more oil and to maintain pressure scatter) in engines with a distributor. if the engine really needs it. A high at higher engine speeds. Such pumps Gerotor style pumps do the same thing volume oil pump is recommended if the typically have redesigned inlet and (smoother output with less pressure engine is being built with “old school” outlet ports to improve flow and reduce pulsation). clearances and will be run on a heavier cavitation, tighter internal clearances to Some people think you have to go viscosity motor oil. Otherwise, a stock reduce pressure losses, and more reliable nuts with oil pressure to prevent the pump should provide adequate pressure and adjustable pressure relief valves. engine from running out of oil. Not true! and flow. Some cast iron pumps may be made Most engines don’t need more than On certain late model applications from a stronger alloy for added strength 10 PSI for every 1,000 RPM. More oil such as Ford’s modular V8 and Coyote and wear resistance, while aluminum pressure just means more horsepower V8, Chrysler’s Hemi and Chevy’s LS, a pumps are usually hard anodized to loss unless there is a need for such (like high volume oil pump may be required minimize wear. The stock pump cover piston oilers or separate oil lines to the if the engine is equipped with Variable may also be replaced with a stronger and upper valvetrain). In fact, reducing oil Valve Timing (VVT). The cam phasers harder cast iron or steel plate. pressure a few PSI can actually gain in these engines need a lot of flow Some aftermarket pumps feature a few horsepower by reducing the oil to function properly (unless you are locking out the phasers to accommodate a high lift, longer duration cam). A high volume pump can also help reduce upper valvetrain noise on some of these engines (such as Ford 4.6L V8s). Something else to keep in mind with respect to front-mounted oil pumps on late model engines is that the pumps can be hard to prime. They are mounted high and dry, and a long ways from the pickup inside the oil pan. Never install one of these pumps dry. Fill it with assembly lube or heavy oil. Also, use a pressure oiler to pre-lube the engine before cranking it over for the first time. If this isn’t done, you may end up with a dry start and pump and/or engine damage as a result. Billet pumps are the ultimate upgrade for a wet sump system. Billet pumps are custom made and optimized with larger ports and taller gears to increase flow and resist cavitation at high RPM. The stronger housing (such as 6061 T6 aluminum) and larger mounting bosses is also better able to resist cracking from engine vibrations and loads. Most billet pumps are a bolt-on replacement for the stock pump, but may also require a special pickup and matching oil pan. They’re also much more expensive than circle 38 for more information 38 June 2016 | EngineBuilder Oiling Systems cast pumps because of the CNC machine work required to make the pump.