What would the rest of you have to say about these comments from Moroso? They appear in the 2008 catalogue on page 135, which discusses Moroso racing oil filters:
After many years of designing and testing racing oil systems and related components, we've collected a good deal of information to determine what's most important to oil filtration. Our conclusion was Total Filtration Time! Many filter manufacturers stress the importance of filtering some of the smallest particles known to man out of your engine's oil. You've probably seen or heard them talk about "micron ratings" of 10 or less when talking about a filter's efficiency.
Moroso engineers have determined, with the help of research performed by filtration technology experts, that particles smaller than 20 microns in diameter are not large enough to produce engine wear. Furthermore, Moroso engineers have also found that filters with extremely low micron ratings create an excessive pressure drop across the filter. They can be so restrictive that the filter by-pass valve can open. And with the by-pass valve open, NO FILTRATION occurs, and you have no way of knowing!
To maximize filter performance, Morose Racing Oil Filters have a rating of 27 microns, which produces a maximum initial restriction of only 2.5 psi when tested to SAE [J]806! The result is less pressure drop, more flow, less oil by=pass and maximum filtration performance that's so important in severe racing conditions.
On the same page:
Filtering out extremely small particles (20 microns or less) is fine for passenger cars with 10,000 mile service intervals—but not for racing or high performance use! Low micron filtration reduces oil flow and pressure, causing the by-pass to open, and eliminating all filtration. Moroso's 27-micron element design [e]nsures full filtration with minimal restriction under the most severe operating conditions!
Moroso clearly intends the comments to apply to racing filters, not necessarily to filters used in street cars. The selection in the catalogue is limited to five: three with 13/16" threads as Chevrolet V-8s would use (short, longer, and extra long 2-quart capacity), one equivalent to the Fram racing HP-6 filter with 1-1/2" threads, and one long filter with 3/4" threads as Ford and Chrysler V-8s would use. Nothing metric. These are clearly the most common applications in North American racing.
But Moroso's comments do lead to some interesting questions. The K&N oil filter line has the same philosophy: flow before filtration. Yet some BITOG members have gotten good URLs with K&N filters on the street. Of course, everyone here would probably agree that unfiltered flow, as when the bypass kicks in, is better than no flow at all. Could it be that some of us have been a little too anal about filtration? Would Moroso's statements broadly apply to street engines as well? Why worry about particles of less than 20 microns? Hmm?...
And think about this. Just after I became a BITOG member many moons ago, I recall a post from someone that went something like this: Place a sheet of plywood flat 1" above a table, representing bearing surfaces in an engine enlarged many times. Roll marbles between the plywood and the table to represent particles that get through a high-flow oil filter. The marbles roll freely because there's plenty of room in that 1" gap. So how would these small particles cause engine wear? Is it worth it at all to try to filter them out?
After many years of designing and testing racing oil systems and related components, we've collected a good deal of information to determine what's most important to oil filtration. Our conclusion was Total Filtration Time! Many filter manufacturers stress the importance of filtering some of the smallest particles known to man out of your engine's oil. You've probably seen or heard them talk about "micron ratings" of 10 or less when talking about a filter's efficiency.
Moroso engineers have determined, with the help of research performed by filtration technology experts, that particles smaller than 20 microns in diameter are not large enough to produce engine wear. Furthermore, Moroso engineers have also found that filters with extremely low micron ratings create an excessive pressure drop across the filter. They can be so restrictive that the filter by-pass valve can open. And with the by-pass valve open, NO FILTRATION occurs, and you have no way of knowing!
To maximize filter performance, Morose Racing Oil Filters have a rating of 27 microns, which produces a maximum initial restriction of only 2.5 psi when tested to SAE [J]806! The result is less pressure drop, more flow, less oil by=pass and maximum filtration performance that's so important in severe racing conditions.
On the same page:
Filtering out extremely small particles (20 microns or less) is fine for passenger cars with 10,000 mile service intervals—but not for racing or high performance use! Low micron filtration reduces oil flow and pressure, causing the by-pass to open, and eliminating all filtration. Moroso's 27-micron element design [e]nsures full filtration with minimal restriction under the most severe operating conditions!
Moroso clearly intends the comments to apply to racing filters, not necessarily to filters used in street cars. The selection in the catalogue is limited to five: three with 13/16" threads as Chevrolet V-8s would use (short, longer, and extra long 2-quart capacity), one equivalent to the Fram racing HP-6 filter with 1-1/2" threads, and one long filter with 3/4" threads as Ford and Chrysler V-8s would use. Nothing metric. These are clearly the most common applications in North American racing.
But Moroso's comments do lead to some interesting questions. The K&N oil filter line has the same philosophy: flow before filtration. Yet some BITOG members have gotten good URLs with K&N filters on the street. Of course, everyone here would probably agree that unfiltered flow, as when the bypass kicks in, is better than no flow at all. Could it be that some of us have been a little too anal about filtration? Would Moroso's statements broadly apply to street engines as well? Why worry about particles of less than 20 microns? Hmm?...
And think about this. Just after I became a BITOG member many moons ago, I recall a post from someone that went something like this: Place a sheet of plywood flat 1" above a table, representing bearing surfaces in an engine enlarged many times. Roll marbles between the plywood and the table to represent particles that get through a high-flow oil filter. The marbles roll freely because there's plenty of room in that 1" gap. So how would these small particles cause engine wear? Is it worth it at all to try to filter them out?
