The problem with not detecting a leak is that the filter minder only shows the highest reading seen since reset.
So if you started off with no hole, the minder went up to whatever restriction the filter causes, and it will not go down on its own if the circumstances change. .
One way to get around this is to reset the minder periodically. Say, if the minder currently reads 2", it will never read less
unless you reset it. And that is one way to discover a leak. Reset the minder, and run the engine up to the operating RPM.
If the filter is OK the minder quickly will go back to the previous value. If it remains close to 0
then you have a tear/leak. If you do this with the engine running, this can be done pretty quickly.
If you have a cylindrical filter with a primary, and secondary "safety" filter, you can probably stop worrying about holes or leaks in the filter.
The likelihood of getting a hole in both filter layers is pretty small I would think. A field mouse would have to get in there, and chew through quite a bit of filter media,
and the housing kinda makes that impossible. This is more of a worry for a flimsy, single layer paper filter. But there you probably would not even bother
installing a minder, esp that you would have to drill into the intake tube for it.
BTW. Small 2 cylinder engines up to 25 HP are typically 8" restriction max. A small, single cylinder engine maybe 3-5" max.
A common passenger sedan would be 20" max. I think the air restriction goes up with the increase of the air quantity sucked through the filter.
The airflow is linear with both the RPM and engine CID.
So if you started off with no hole, the minder went up to whatever restriction the filter causes, and it will not go down on its own if the circumstances change. .
One way to get around this is to reset the minder periodically. Say, if the minder currently reads 2", it will never read less
unless you reset it. And that is one way to discover a leak. Reset the minder, and run the engine up to the operating RPM.
If the filter is OK the minder quickly will go back to the previous value. If it remains close to 0
then you have a tear/leak. If you do this with the engine running, this can be done pretty quickly.
If you have a cylindrical filter with a primary, and secondary "safety" filter, you can probably stop worrying about holes or leaks in the filter.
The likelihood of getting a hole in both filter layers is pretty small I would think. A field mouse would have to get in there, and chew through quite a bit of filter media,
and the housing kinda makes that impossible. This is more of a worry for a flimsy, single layer paper filter. But there you probably would not even bother
installing a minder, esp that you would have to drill into the intake tube for it.
BTW. Small 2 cylinder engines up to 25 HP are typically 8" restriction max. A small, single cylinder engine maybe 3-5" max.
A common passenger sedan would be 20" max. I think the air restriction goes up with the increase of the air quantity sucked through the filter.
The airflow is linear with both the RPM and engine CID.
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