I helped a friend pull down his chevy 396 bbc, engine he recently purchased, off craigs list, and noticed a non-stock oil pump was installed, looking it over its got some rather different / interesting features , the main two that stick out is a spring loaded check/ball ,that works similar to the bye-pass circuit in a normal oil pump, but instead of routing oil from the high pressure side of the pump gears ,back through a internal passage, in the lower pump casting, too the feed side or suction side of the impeller gears in the pump, it simply dumps any excess oil volume directly out the pump base, this will by design work almost instantly, and has far less potential for the spring loaded check ball, too get stuck, bind or restrict oil flow like the more common, standard design with a spring loaded piston sliding through a machine tube like passage, would,
if the pump injested micro debris,potentially binding the piston travel, until it travels far enough to open a passage from the pressure to the feed side of the oil pump, or perhaps binding up the piston and preventing the pressure relief circuit from functioning .
While this rarely if ever happens with the stock pump design it is potentially an issue and the check ball valve design almost assures the pump takes meassurably less effort to turn once the pressure builds up.
one the potential faults of the design,
the direct dump of high pressure oil into the oil pan sump has some potential to cause excess airation or foam and micro air pockets to be induced, thats the reason for the preforated screen under the pump base, it in theory prevents a direct high pressure jet of oil pumping air into the oil in the sump,
KEEP IN MIND the crank shafts already spinning thousands of rpms ,churning the oil thats trapped in the sump, one reason a windage tray, and a baffled 7-9 quart oil pan is strongly suggested in any performance engine build
http://www.schumannsdynamicperformance.com/oil-pumps/big-block-chevy.html
RELATED INFO
http://garage.grumpysperformance.co...l-pumps-pressure-bye-pass-circuit-works.3536/
http://garage.grumpysperformance.co...oil-passages-and-improved-oil-flow-mods.3834/
http://garage.grumpysperformance.com/index.php?threads/whats-a-windage-tray-do.64/
if the pump injested micro debris,potentially binding the piston travel, until it travels far enough to open a passage from the pressure to the feed side of the oil pump, or perhaps binding up the piston and preventing the pressure relief circuit from functioning .
While this rarely if ever happens with the stock pump design it is potentially an issue and the check ball valve design almost assures the pump takes meassurably less effort to turn once the pressure builds up.
one the potential faults of the design,
the direct dump of high pressure oil into the oil pan sump has some potential to cause excess airation or foam and micro air pockets to be induced, thats the reason for the preforated screen under the pump base, it in theory prevents a direct high pressure jet of oil pumping air into the oil in the sump,
KEEP IN MIND the crank shafts already spinning thousands of rpms ,churning the oil thats trapped in the sump, one reason a windage tray, and a baffled 7-9 quart oil pan is strongly suggested in any performance engine build
http://www.schumannsdynamicperformance.com/oil-pumps/big-block-chevy.html
Small block Chevy low volume Drag Race oilpump.. In a typical OE application, engineers calculate the bearing clearances, journal sizes an so forth throughout the engine. From there they can estimate the volumetric requirments for oil. Then they design a pump that is 30% larger than the maximum requirements. But in today\\\'s drag racing engines tighter clearances and lighter oil are run and experts say that the extra 30% of oil is not needed and just robs extra horsepower pumping it through the engine. Schuman sbc pumps have several additional features over the stock pump. On the driven shaft in the pump they have taken the time to machine oil retention grooves the length of the housing,this gives oil a place to flow and in exchange has a higher change over rate of oil. The rotation of the oil pump actually hinders the oil from getting in there as it is being thrown to the outside by centrifugal force. a notch is machined in the bottom of the floor of the pump housing, under the gear that takes oil from the pressure side of the pump and pushes it underneath the gear which is chamfered and a oil groove is machined in the oil hole to insure oil is getting in there. All schuman pumps are built using a custom one off casting, they do not use cut down gears and spacer plates to reduce the volume of oil. Our gears are custom built and made length specific along with the pump housing itself and all of this is at a third of the cost. Schumann oil pumps have the following unique characteristics not found in other pumps: Full flow driven shaft oiling Anti-aeration bleed off of oil supply chevy oil pumps have high strength iron alloy casting and casting technique that eliminates 80% of porosity (70,000 psi)where as a typical pump has a more porous 35,000 psi design. each unit is built with precision tolerance machining. The unit features a drilled cap screw for easy cleaning and oil pressure spring changes. Exact mesh gear set to housing bore yields highes idle psi. Mounting bolt neck to housing is 150 grams heavier than typical chevy industry oil pump. each unit includes extra long bolts to accommodate aftermarket performance bolt-on screen assemblies. Also included are three spring combinations for desired oil pressure selection (55lb) (65-70lb) and (80-90lb)[/img]
http://www.enginebuildermag.com/2009/06/oil-pump-technology/
http://www.enginebuildermag.com/2004/01/oil-pumps-the-heart-of-the-engine/
RELATED INFO
http://garage.grumpysperformance.co...l-pumps-pressure-bye-pass-circuit-works.3536/
http://garage.grumpysperformance.co...oil-passages-and-improved-oil-flow-mods.3834/
http://garage.grumpysperformance.com/index.php?threads/whats-a-windage-tray-do.64/
Last edited: