I have been interested in oil lately and decided to try a bypass filter took a wile to choose one
wound up with an Oil Guard eps-20 seamed like a good match for what i wanted to do, it was $130 for just the filter case no lines or fittings, they sell complete kits that come with the lines for slightly more, replacement filters are $13 but I am looking into a possible source for the same filters for $5 these filters are suppose to be changed at every oil change
for this kind of bypass filter I needed a high pressure oil source and a low pressure area to return the bypassed oil to. The oil sending unit on this motor is buried deep behind the intake and almost impossible to get to, fortunately there is a 3/8 NTP plug on the side of the block along the center line of and just above the oil filter. It covers a drilled oil passage that taps oil off just after it passes through the main oil filter and oil cooler
I wanted to know what 1 was going to be working with (drive and thread) before I took it apart so I went to the dealer and got the # for the plug (not in stock) and ordered from GM parts direct, I received a 1/4NPT plug with a 1/4” female square drive. unfortunately I went to install and the plug on my truck has a square drive that is smaller than 3/8 and larger than ¼ and the thread is 3/8NPT
I took an old POS 3/8 ratchet and slowly ground it down until it fit. seams to be around .320” witch lines up with 8mm and is also close to 5/16
so did the dealer parts person screw up or maybe GMPD or are there 2 different plugs on 8.1's?
Here I installed a 3/8”npt to 1/4”npt bushing in the block, 1/4”npt street el, 1/4”npt to 1/4”barb, hose and 2 clamps, I was worried about a catastrophic hose failure bleeding off all of my oil pressure, the filter has a .042” restriction in its outlet but if there was a failure before then it would immediately dump all my oil pressure so I made a second restrictor for right where the oil comes out of the block
I took a 3/16 monel rivet with a 426 head (large countersink) and drilled a #40 hole (.098”) down its length counter sunk each end slid it into the base of the barb, and using 2 punches and a hammer I slightly swelled the rivet to hold it in place and then re drilled the hole as it has closed slightly
now if there is a major failure there should still be oil pressure for a few minutes, some of the oil will be pumped overboard through the .1” restriction but not ehough to cause a loss of pressure, when the level gets 2qt low low oil level light will come on, the remaining oil should give me enough time to pull over to the sholder without engine damage
The second problem is where to mount the filter, there is a heat shield on the bottom of the cab just below the drivers feet just inboard of the frame, perhapses there is a cat here with other motors? This heat shield is installed with 3 bolts and is close to the oil filter and there are no obstructions in the area, looking at the air tunnel that every thing on my truck works its way around I think it will clear the front drive shaft for you guys with 4wd
the bracket it came with was not wide enough to catch the 2 front bolts so I bolted it to a piece of 2” alloy aluminum angle that was 11” long I then added a brace to the rear bolt to help out as these heat shield bolts are kinda thin and the filter had a lot of leverage on them the rear brace negates that leverage
view looking up at the drivers side floor, the head of the filter faces forward,
both inlet out outlet of the filter are 1/4npt I installed 2 street el's and 2 1/4”npt to 1/4” barbs hose with 2 clamps, there was also an 1/8”npt port marked aux, this is ported to the “dirty side” of the filter I decided to put a sampling port there got a valve that has a all metal seat there is a rubber seal around the handle shaft but it sees no pressure except when the valve is open I put a short piece of 3/16 vinyl hose on it and jamed a 3/16 bolt in the end of the hose as a dust cap, do not want dirt/grime to contaminate the sample
the last thing to figure out is where to return the bypassed filtered oil to, you can buy hollow self taping bolts. you would punch a hole in the oil pan or valve cover and thread them in, on the 8.1l both are cast aluminum and I was not to keen on that method anyway
Amsoil sells a swivel for the oil cap with a nut on the back side for only $8 but I am not sure how well that swivel seals? Seams to me that if it gets worn out the vacuum in the motor would draw in air and the dust/grit that travels with it, I would like to hear from somebody that has one how it worked out? That amsoil swivel is 1/8npt but I could adapt
I wound up drilling and taping the oil fill cap for the return, I am not really happy with this setup wile the oil cap is off it drips oil all over the intake and since it has hose on it I cannot flip it over or move it elsewhere to prevent the drip also the cap is not solid but several layers of thin plastic not very forgiving of threaded fastners, I don not think it will last long, I have the gasket needed and may one day remove drill and tap the valve cover for the return line, in the mean time I am going to look for another way, I am still hoping to find a stock plug somewhere that I can tap into
here used 2 clamps a 1/4”barb to 1/4”npt, 1/4” elbow, and a 1/4” to 3/8” MS fillting witch is 7/16-20 strait thread, drilled a 3/8” hole in the cap and taped it, there is an o-ring between the fitting and cap to seal it
I also want to get better hose, the only 1/4” oil and temperature resistant hose I could find in Newnan was hydraulic hose, it was made for swage on fittings, I am using barbs and hose clams (witch are appropriate for the 70PSI it will see) but the 15,000 psi hydraulic hose has a metal wire layer that soaks up a lot of the hose clamps pressure and I am worried about it popping off I will be ordering some Parker 836-4 hose witch is ¼ id high temperature 300psi line, should be perfect, the filter could be installed with 10' of hose and still be well routed
I took a sample just after start, this oil has 2k on it, hopefully there is nothing in the lines thread sealant or the filter head that will throw off the UOA, I will be changing at 4k and take another sample for comparison of the same oil before and after bypass filtration
[ November 04, 2003, 08:25 PM: Message edited by: RavenTai ]
wound up with an Oil Guard eps-20 seamed like a good match for what i wanted to do, it was $130 for just the filter case no lines or fittings, they sell complete kits that come with the lines for slightly more, replacement filters are $13 but I am looking into a possible source for the same filters for $5 these filters are suppose to be changed at every oil change
for this kind of bypass filter I needed a high pressure oil source and a low pressure area to return the bypassed oil to. The oil sending unit on this motor is buried deep behind the intake and almost impossible to get to, fortunately there is a 3/8 NTP plug on the side of the block along the center line of and just above the oil filter. It covers a drilled oil passage that taps oil off just after it passes through the main oil filter and oil cooler
I wanted to know what 1 was going to be working with (drive and thread) before I took it apart so I went to the dealer and got the # for the plug (not in stock) and ordered from GM parts direct, I received a 1/4NPT plug with a 1/4” female square drive. unfortunately I went to install and the plug on my truck has a square drive that is smaller than 3/8 and larger than ¼ and the thread is 3/8NPT
so did the dealer parts person screw up or maybe GMPD or are there 2 different plugs on 8.1's?
Here I installed a 3/8”npt to 1/4”npt bushing in the block, 1/4”npt street el, 1/4”npt to 1/4”barb, hose and 2 clamps, I was worried about a catastrophic hose failure bleeding off all of my oil pressure, the filter has a .042” restriction in its outlet but if there was a failure before then it would immediately dump all my oil pressure so I made a second restrictor for right where the oil comes out of the block
I took a 3/16 monel rivet with a 426 head (large countersink) and drilled a #40 hole (.098”) down its length counter sunk each end slid it into the base of the barb, and using 2 punches and a hammer I slightly swelled the rivet to hold it in place and then re drilled the hole as it has closed slightly
now if there is a major failure there should still be oil pressure for a few minutes, some of the oil will be pumped overboard through the .1” restriction but not ehough to cause a loss of pressure, when the level gets 2qt low low oil level light will come on, the remaining oil should give me enough time to pull over to the sholder without engine damage
The second problem is where to mount the filter, there is a heat shield on the bottom of the cab just below the drivers feet just inboard of the frame, perhapses there is a cat here with other motors? This heat shield is installed with 3 bolts and is close to the oil filter and there are no obstructions in the area, looking at the air tunnel that every thing on my truck works its way around I think it will clear the front drive shaft for you guys with 4wd
the bracket it came with was not wide enough to catch the 2 front bolts so I bolted it to a piece of 2” alloy aluminum angle that was 11” long I then added a brace to the rear bolt to help out as these heat shield bolts are kinda thin and the filter had a lot of leverage on them the rear brace negates that leverage
view looking up at the drivers side floor, the head of the filter faces forward,
both inlet out outlet of the filter are 1/4npt I installed 2 street el's and 2 1/4”npt to 1/4” barbs hose with 2 clamps, there was also an 1/8”npt port marked aux, this is ported to the “dirty side” of the filter I decided to put a sampling port there got a valve that has a all metal seat there is a rubber seal around the handle shaft but it sees no pressure except when the valve is open I put a short piece of 3/16 vinyl hose on it and jamed a 3/16 bolt in the end of the hose as a dust cap, do not want dirt/grime to contaminate the sample
the last thing to figure out is where to return the bypassed filtered oil to, you can buy hollow self taping bolts. you would punch a hole in the oil pan or valve cover and thread them in, on the 8.1l both are cast aluminum and I was not to keen on that method anyway
Amsoil sells a swivel for the oil cap with a nut on the back side for only $8 but I am not sure how well that swivel seals? Seams to me that if it gets worn out the vacuum in the motor would draw in air and the dust/grit that travels with it, I would like to hear from somebody that has one how it worked out? That amsoil swivel is 1/8npt but I could adapt
I wound up drilling and taping the oil fill cap for the return, I am not really happy with this setup wile the oil cap is off it drips oil all over the intake and since it has hose on it I cannot flip it over or move it elsewhere to prevent the drip also the cap is not solid but several layers of thin plastic not very forgiving of threaded fastners, I don not think it will last long, I have the gasket needed and may one day remove drill and tap the valve cover for the return line, in the mean time I am going to look for another way, I am still hoping to find a stock plug somewhere that I can tap into
here used 2 clamps a 1/4”barb to 1/4”npt, 1/4” elbow, and a 1/4” to 3/8” MS fillting witch is 7/16-20 strait thread, drilled a 3/8” hole in the cap and taped it, there is an o-ring between the fitting and cap to seal it
I also want to get better hose, the only 1/4” oil and temperature resistant hose I could find in Newnan was hydraulic hose, it was made for swage on fittings, I am using barbs and hose clams (witch are appropriate for the 70PSI it will see) but the 15,000 psi hydraulic hose has a metal wire layer that soaks up a lot of the hose clamps pressure and I am worried about it popping off I will be ordering some Parker 836-4 hose witch is ¼ id high temperature 300psi line, should be perfect, the filter could be installed with 10' of hose and still be well routed
I took a sample just after start, this oil has 2k on it, hopefully there is nothing in the lines thread sealant or the filter head that will throw off the UOA, I will be changing at 4k and take another sample for comparison of the same oil before and after bypass filtration
[ November 04, 2003, 08:25 PM: Message edited by: RavenTai ]
