You read it right.
This was only for my boat however. Most gas marine engines do not have an air filter at all. They have a metal grille called a flame arrestor, that more aptly fits the description of "rock catcher" than anything usually targeted by that reference on this site. The idea is that it's better to sacrifice filtering ability than to allow a backfire to ignite gasoline fumes in the engine bay, turning it into a bomb.
My Wellcraft Nova III project boat has two of these; one above each of its twin 454 V8 engines. One had apparently been badly manipulated while owned by the PO, and required replacement.
While searching for a replacement arrestor online, I happened to notice that K&N offers a true USCG SAE J1928 approved air filter/flame arrestor.
However pathetic the filter media is, I'm not biased enough against them to believe it as bad as open metal slats that I can feed solid objects between. I've routinely removed flame arrestors, to find a healthy amount of sand behind the slats. They do nothing to stop it.
I honestly cannot say I've ever had an engine fail because of the flame arrestor drawbacks, but I would like to see the difference in Si, and the K&Ns were available cheaper than a replacement arrestor. Power increase? Who knows. Takes a lot to make a noticeable difference on a boat.
But again, the only compliment I can give K&N, is that it's better than open metal slats, and cheaper. I'm still not putting one of these things in any of my cars.
This was only for my boat however. Most gas marine engines do not have an air filter at all. They have a metal grille called a flame arrestor, that more aptly fits the description of "rock catcher" than anything usually targeted by that reference on this site. The idea is that it's better to sacrifice filtering ability than to allow a backfire to ignite gasoline fumes in the engine bay, turning it into a bomb.
My Wellcraft Nova III project boat has two of these; one above each of its twin 454 V8 engines. One had apparently been badly manipulated while owned by the PO, and required replacement.
While searching for a replacement arrestor online, I happened to notice that K&N offers a true USCG SAE J1928 approved air filter/flame arrestor.
However pathetic the filter media is, I'm not biased enough against them to believe it as bad as open metal slats that I can feed solid objects between. I've routinely removed flame arrestors, to find a healthy amount of sand behind the slats. They do nothing to stop it.
I honestly cannot say I've ever had an engine fail because of the flame arrestor drawbacks, but I would like to see the difference in Si, and the K&Ns were available cheaper than a replacement arrestor. Power increase? Who knows. Takes a lot to make a noticeable difference on a boat.
But again, the only compliment I can give K&N, is that it's better than open metal slats, and cheaper. I'm still not putting one of these things in any of my cars.
