Q- "What is" and "why use", a dry sump system?
A- see "Technical Explanation"
Q- Where and how should I mount the vent/catch can?
A- View pictures of our new Cast CNC 7007A Dry Sump Oil Tank installed in a ZO6 Corvette. Note position of vent can and height so that the line from vent can slopes gradually to the top of the dry sump tank. This applies to all tanks. Otherwise there can be a "toilet trap" effect in the vent line, or simple filling of the vent can with oil mist accumulating in the line.
Q- What size pump should I use?
A- If we know the flow demands of your particular engine, we will recommend our pump size or GPM, for you to use. otherwise, we can measure the size of the factory pressure pump and calculate the best size for your engine.
Q- How many scavenge stages should I use?
A- On normally aspirated engines making moderate HP, 2 scavenge stages are adequate. Adding a 3rd will always help, but may not be needed. At ARE ,the science of designing very efficient windage trays in our dry sumps helps trap the oil and "make it available" to the pick-ups better, thus making fewer stages efficient. On higher HP, RPM and supercharge turbocharged engines, 3 scavenge stages will normally be recommended. We also make ROOTS type scavenge stages, which can be another option.
Q- What about ROOTS scavenge?
A- The Roots design usually will move more air, however, in 38 years of dry sump designing we still prefer the gear type if a choice has to be made. This is again, because of the efficiency of the dry sump pan makes the gear scavengers more efficient when better supplied with oil. However... On our LS and other LeMans etc. type engines, I prefer to incorporate both into our pumps. We use 2) gear type scavenges and 1) ROOTS scavenge all bifurcated together at the outlet. This gives the best of both worlds. Note: some of these Q&A's will be better suited for discussion when you order. Only providing basic info here, as there are potential variations.
Q- Why does A R E only use and manufacture gear type ( and roots) dry sump pumps?
A- There are many types / variations of pumps. Fluid dynamics is also a very complex science. However, in racing engines many things are constants, such as high demand for reliability, efficiency and hopefully, long lasting use. It is inevitable that there will be small bit of debris injested in running any engine, over time and use ( in racing that means abuse) any amount of wear created in these precision pump housings from particles and debris cuts down on the efficiency of the pump dramatically. It is a fact that gear pumps are very tolerant of debris, and have the ability to "move" it to the main oil filter with less damage to the housings. There are also more sealing surface areas present. Each gear is supported by a shaft, allowing it to make no contact to the outer housing. Another fact is we only want to use a fairly high micron screen filter before the pump so not to restrict scavenging. All this being said, the same "discussion" mentioned in the last QA applies here too.
Q- What RPM should the pump run at?
A- A general rule is 50-60% of crank speed. This of course is also based on the max engine RPM that will be achieved. Dry sump pumps can start losing efficiency, and in fact begin cavitation at RPM above 4500-5200 PUMP RPM. Like a camshaft, dry sump pumps have an efficiency range that they should be run at to maintain it's best performance.
Q- How do i adjust the oil pressure on the dry sump pump?
A- At the rear of the pressure stage, on bottom, is a set screw and jam nut. Loosen the jam nut and turn the Allen screw in CLOCKWISE to INCREASE pressure, and COUNTER-CLOCKWISE to reduce pressure. Do this when the engine has been run, and oil is warm. Depending on many factors, the pressure will increase / decrease by approx. 20 PSI per complete turn. Tighten jam nut, and re-check pressure. Keep in mind that under full racing conditions and hot oil, is when the pressure reading should be established.
Q- What type of pump drive should I use, and how do we order it?
A- If you buy an ARE system, the drive components are supplied, however the belt length on systems that you mount the pump position yourself, the belt length will need to be calculated. We will do these calculations for you if necessary. These are achieved by varying the pulley sizes / belt length based on the center to center distance between the center of the oil pump shaft and the center of the crankshaft. If you are making your own pump mount, or using our universal mount plate and mounting the pump in the desired location that fits your engine / chassis, then we need that center to center measurement before we can supply the proper pulley / belt combination. We also will take into consideration pump speed at this time. The types of drives we use are: Gilmer or tooth (timing) type, HTD or round tooth metric type , and serpentine belt type. The serpentine type is only used with "scavenge only" systems. The power required to drive a pressure pump will allow the serpentine belts to slip. The drive assemblies are shown on the web site at Drive Assemblies the gilmer and HTD pulleys require belt guides to stop the belt from slipping off. See drawing at http://www.drysump.com/TechDrawings/DriveSetupExample.PDF
Q-What size Dry Sump Tank should I use?
A- There are several factors in choosing the size of your Dry Sump Tank.
First is location or where you plan to mount it. This varies greatly and depends on the type of race car. Most production type race cars do not offer a lot of good choices, however, the best choice, if it is possible, would be in the passengers compartment. Not only is there ample room, but it is relatively close to the engine and perfect for weight distribution. Be sure to check the rules for your sanctioning body. Some do not allow them in the drivers compartment, others require that a separate tank enclose the dry sump tank. For Formula and Sports Racing cars the tank location has usually been selected by the car designer. Otherwise use the parameters as mentioned in production race cars.
Second factor, most inportantly is Oil Volume. Oil is, after all, the life blood of your racing engine. Some racers are quick to want a small tank because it "fits better", forgetting that this is supplying all the oil for your high dollar engine. Expecting a 7 liter 800 HP engine to survive on 5 quarts of oil is pushing your luck, especially in high lateral G racing. We use all the laws of physics and fluid dynamics to desig our dry sump tanks (as well as all our pans) to enable them to overcome the extreme acceleration and lateral (as well as braking) forces, and this achieves amazing results. High tech race tested baffels, "fluidic" scavenge return line internally, adn venting control is the trademark oa ARE and Spintric Technologies dry sump oil tanks and systems.
Along with this, common sense goes a long way in selecting a tank. Always try to use the tallest, or biggest tank you can make fit, even if it means moving the tank to another location in the race car. See tank sizes here Dry Sump Cast A-Series Oil Tanks Sizes. Read below about fitting sizes and tank pre-heaters.
ALSO when we say "size of tank" ie: 2 gallon, 2.5 gallon or 3 gallon, this equals the volume of the tank including the air gap at the top.
Q-What size fittings should I use on my Dry Sump Tank?
A- For most Dry Sump Tanks, use the same size fittings as there are on the scavenge outlet and pressure inlet on your Dry Sump Pump. Most racing engines use -12 or -16. This is based on your racing engines oil demands, and the tank fittings need to be the same. In Dry Sump Tanks that are mounted in the trunk, or are more than a few feet away, I recommend using -16 (or larger in some cars) supply line from bottom of tank to pressure stage inlet. This allows a better flow of oil supply to the pump, especially in colder climates. We recommend a tank pre-heater for use in colder climates.
Q-What about cold environments? Anything different?
A-Yes the obvious thing is a lower viscosity oil, however, due to the larger clearances and higher loads in racing, this often results in oil pressure loss when hot. We recommend using an oil heater in colder environments. All Spintric Technologies / ARE CNC tanks are equiped with the pre nachined port in the bottom. These heaters are either 110 volt or 220 volt, and are supplied with a removable 6' plug. The heating element is plugged in 4-6 hours before the engine will be run to get oil temp up to 150-180 degrees.
Q-How do I check or be sure the oil level is correct in my tank?
A-In a dry sump engine, because the oil pan/sump is designed to be mostly dry, the engine needs to have been running just before the level in the tank is checked! This allows the scavenge pumps to "scavenge" most of the oil out of engine and put it in the tank where it belongs.
Q- What type oil filter should be used on the A R E 4010 filter adapter?
A- We recommend a Wix # , ARE # WIX4 Or Fram HP4 These fit small block Chevy 327-350 and are very common. More importantly, the filters have a high by- pass rating so virtually every drop of your oil will be filtered.