Model A oil filter test

Thanks for posting this. One thing I learned is I will always fill a new filter as best I can when installing. That took a long time to fill.
 
The flow you demonstrated with the bypass filter is less than you'd get on the actual setup. The reason is how high you mounted the filter.

In real life, the bypass filter mounts by the timing gear. This is important because it is only the weight/resistance of the volume of oil above the oil pump and in that first galley that creates the back-pressure pushing oil through the secondary line into the bypass filter.

In a modern diesel truck, you'd have both a full-flow filter and a bypass filter, and the FF filter, along with the many constrictions in the oil path, would create resistance that would generate significant pressure at the bypass. But here, there's no FF filter and essentially no oil plumbing, so the only thing that makes oil "want" to go through the bypass filter is gravity acting on all the oil up in the valve chamber to push it back down toward the pump.

If the bypass is mounted above the valve chamber and empties into it, as in the video, then the weight of the oil in the line going to the bypass works against it, causing the flow rate to drop. The real bypass filter is mounted an inch above the sump, so flow from the port on the block into the filter is essentially horizontal. Unlike the main oil flow, the bypass flow doesn't have to fight gravity. The only back-pressure in the line is created by the small diameter of the line and the resistance of the filter media.

I think the concepts demonstrated in the video are broadly accurate, but I don't want folks to get the impression that the relative flow to the bypass is as poor as in your demonstration.

Edit: Having said that, it's certainly true that the bypass will get less flow than the setup that mounts on the valve cover. That's the reason that in the past I've recommended people go with a finer filter than the Motorcraft FL1A or whatever is coming with the kits these days. You're only getting 5% of the flow, so you should run it through the best filter you can.
 
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Very interesting and informative. Thanks for taking the time to make this video. We all learn by sharing our knowledge and experience. I also agree with alexiskai's comment regarding bypass flow and the use of a finer filter. I'm running the bypass filter set up with fine filter. My oil is visually much cleaner after 1000 miles than with no filter at all. I think each system is good with their own pros and cons, and either one will benefit the engine.
 
Alexiskai thanks for the input,if you or anyone else has a timing gear cover filter they would send me to test I would br glad to test with whatever filter anyone would want and I will send it back after the test,Thanks Randall
 
What are the advantages of the bypass filter? Why would one chose the bypass filter instead of the full flow?

W. Michael
 
w.michael said:
What are the advantages of the bypass filter? Why would one chose the bypass filter instead of the full flow?

W. Michael
Click to expand...

  • About 30% cheaper
  • Most people think the bypass kit looks better
  • Permits installation of a filter with a smaller micron rating
  • Theoretically it could reduce the risk of the filter clogging, e.g., if you are switching from non-detergent to detergent oil and are worried about lifting sludge into suspension
 
alexiskai said:
  • About 30% cheaper
  • Most people think the bypass kit looks better
  • Permits installation of a filter with a smaller micron rating
  • Theoretically it could reduce the risk of the filter clogging, e.g., if you are switching from non-detergent to detergent oil and are worried about lifting sludge into suspension
Click to expand...
If you are switching from non detergent to detergent it would be a good idea pull oil pan and valve cover and clean, because of the screen around oil pump
 
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In the video it took close to 2 minutes to fill the filter and get oil flowing into the engine, that's scary. What shape is the pump in? If you take the actual filter off the adapter, how long does it take to for oil to come out the adapter? What speed are you rotating the camshaft at? Methinks it should be at least 200 rpm.
 
katy said:
In the video it took close to 2 minutes to fill the filter and get oil flowing into the engine, that's scary. What shape is the pump in? If you take the actual filter off the adapter, how long does it take to for oil to come out the adapter? What speed are you rotating the camshaft at? Methinks it should be at least 200 rpm.
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The vid stated it was turning at 500rpm. I don't know anyone that installs an oil filter dry. Even on a modern.

I would like to see the test again with a full filter and more than 2 quarts of oil in the pan. You can see the pump is loosing suction by the air bubbles.

As for the filter clogging, that is what the bypass valve built into the filter is for.

Thanks for your efforts Randall.
 
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I am using a Wix filter on the valve cover style oil filter. As per Paul Shin he suggested drilling out the backflow gasket. I instead cut slits with exacto knife. When oil pressure builds up, you can hear the engine sound change after a few seconds, so oil is circulating quickly. Oil stays very clean and can monitor pressure on gauge. When cold idle pressure 12 psi, hot near zero.
 
goldie said:
As per Paul Shin he suggested drilling out the backflow gasket. I instead cut slits with exacto knife.
Click to expand...

With the full-flow kit, it doesn't much matter whether you puncture the anti-drainback membrane or not, because the entry port from the pump is at the top of the filter. So there's nowhere for oil to go, whether it drains back out through the membrane or not. However, technically there is very little evidence for the practice of puncturing the membrane. If you want to be extra certain, use a filter with a silicone (red) membrane instead of the nitrile (black) membrane seen in the video. Nitrile membranes can sometimes harden if left in place for years.
 
I use the partial flow system with an fl1a filter or equivalent and here is my 2 cents on it. The partial flow does indeed filter all of the oil, but not at once, hence the name partial flow. the partial flow system has by design a failsafe if the filter were to plug up. it will still allow oil to flow to the bearings and to the rest of the motor and will basically act like a plug. and the fl1a filter is easy to slit the drainback valve. I do cut the valve because the original pump is not made to pressurize anything, its ment to quickly move oil into the valve gallery. so by cutting it it makes it flow well and it prevents damage to the pump. I also make a foam filter that goes in the oil fill cap to keep dust and trash from going into the sump, it keeps it clean, and the foam breathes well so no fear of pressurizing the system and blowing something. finally, the last reason I use that system is that the oil partially flows downhill into the sump across the timing gears after it exits the filter, so it starts filtering very quickly and there is no fear of starving bearings when starting up. that's my 2 cents, take what you want from it.
 
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