Frequently Asked Questions (FAQ)
Q- *What is" and " why use", a dry sump system?
A- see "Technical Explanation" on web site (here)
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 A R E ,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 Le Mans 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 loosing 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 A R E 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 nescissary. 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 http://www.drysump.com 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 type oil filter should be used on the A R E 4010 filter adapter?
A- We recommend a Wix # , A R E # 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.