I got the informations about micron sizes and what they are comparative to from here:http://www.tpub.com/content/fc/14104/css/14104_153.htm
And from here (a site with PDF file):http://www.filtercouncil.org/techdata/tsbs/89-5R3.pdf
The latter if from the "Filter Council" of the automotive industry in fluid technology. I did not want anyone to think I just "pulled them out of the air", but were already researched information out there.
A micron or Micro-meter is only 39 millionth of an inch! Anything less than a micron then gets proportionally smaller by a factor of 10. I worked at Boeing where some of our closer tolerance holes we drilled were held to +/- 1/10,000 of an inch aka 0.0001". Micron is 0.000039".
RalphPWood stated: "Where you really get into tight clearances are things like piston rings, valve train and automatic transmission, valve body and control valves. These parts are down to 0.1 clearances." This needs to be quantified a bit. is the "0.1 clearance" in inches or millimeter? It cannot be in micron as one must remember that as metal heats it expands and there HAS to be allowance for expansion and contraction or metal would quickly seize to itself. Piston rings are a great example. Something is needed to provide a seal between the piston wall and the cylinder, or else the piston would seize to the cylinder as soon as it got fairly warm *hot, ergo, piston rings that allow "slop" between the pistons and the cylinder walls.
Main bearings, rod bearings, etc etc are all similar situations. Metal has tremendous expansion and contraction ability and without some "looseness" you would be in deep do-do.
I remember at Boeing that critical holes would be drilled on the thrust control lever of the 747 airplanes and they would be held to a very close tolerance (I know... I drilled them *S*). Then upstairs in assembly they would put bronze/aluminum/nickel bearings in a special cooler on top of dry ice as they heated the thrust control levers to 140 F. Then the cold "bronze" bushing would be pressed into the hole in the heated lever and when they would come to equilibrium that bearing was in there for life.
Sorry to get off topic, but when you talk about close tolerance and moving parts within an engine you must take into account of expansion of metals.
I remember back several year of a demonstration I saw of an Amsoil bypass filter. It was rigged up with a clear oil reservoir so you could see the oil pumping around in there. Then the distributor introduced lamp black (carbon) to the oil and it became instantly dirty. Then he switched the lever and allowed the oil to flow through the bypass filter and 'no more dirty oil'. Really was an awe inspiring demo
As for me, I will/would be quite content with any filter that went down to <5 microns considering the cost:effectiveness ratio.
And from here (a site with PDF file):http://www.filtercouncil.org/techdata/tsbs/89-5R3.pdf
The latter if from the "Filter Council" of the automotive industry in fluid technology. I did not want anyone to think I just "pulled them out of the air", but were already researched information out there.
A micron or Micro-meter is only 39 millionth of an inch! Anything less than a micron then gets proportionally smaller by a factor of 10. I worked at Boeing where some of our closer tolerance holes we drilled were held to +/- 1/10,000 of an inch aka 0.0001". Micron is 0.000039".
RalphPWood stated: "Where you really get into tight clearances are things like piston rings, valve train and automatic transmission, valve body and control valves. These parts are down to 0.1 clearances." This needs to be quantified a bit. is the "0.1 clearance" in inches or millimeter? It cannot be in micron as one must remember that as metal heats it expands and there HAS to be allowance for expansion and contraction or metal would quickly seize to itself. Piston rings are a great example. Something is needed to provide a seal between the piston wall and the cylinder, or else the piston would seize to the cylinder as soon as it got fairly warm *hot, ergo, piston rings that allow "slop" between the pistons and the cylinder walls.
I remember at Boeing that critical holes would be drilled on the thrust control lever of the 747 airplanes and they would be held to a very close tolerance (I know... I drilled them *S*). Then upstairs in assembly they would put bronze/aluminum/nickel bearings in a special cooler on top of dry ice as they heated the thrust control levers to 140 F. Then the cold "bronze" bushing would be pressed into the hole in the heated lever and when they would come to equilibrium that bearing was in there for life.
Sorry to get off topic, but when you talk about close tolerance and moving parts within an engine you must take into account of expansion of metals.
I remember back several year of a demonstration I saw of an Amsoil bypass filter. It was rigged up with a clear oil reservoir so you could see the oil pumping around in there. Then the distributor introduced lamp black (carbon) to the oil and it became instantly dirty. Then he switched the lever and allowed the oil to flow through the bypass filter and 'no more dirty oil'. Really was an awe inspiring demo
As for me, I will/would be quite content with any filter that went down to <5 microns considering the cost:effectiveness ratio.
