Originally Posted By: NJC
Originally Posted By: 440Magnum
Originally Posted By: NJC
I'm speculating here - but the problem could be weak media (numerous failures are possible) or lacking pitch uniformity at media to end cap bond. I haven't studied other filter designs enough to know if this is typical, but it looks like the pleats are too tight for majority of glue joint, and too wide near seam.
I agree with ZeeO that this is the best working theory. Where the theory comes apart a little (pun intended) is that if pleat uniformity were the only factor, then EVERY entry-level Fram-built filter (Orange can and clones) would do this, because they are far more wide-pleated in places than a Purolator Classic. Just speculating here, but maybe the Fram Orange Can's end caps made of filter media actually save it. Maybe its the stress of a flexible medium glued to a rigid metal end cap. Or maybe its the Classic media is softer than the cheapy Fram media.
I dont' think its just one cause, its at least two or more contributing factors coming together.
I think this is the correct, multiple causes. If I had to hazard a guess and pick a culprit, I'd go with weakened media. Not necessarily too thin (as per pictures above, the media from Bosch 3330 measure .6mm or .024") but too weak - either weak design or batch, or weakened with oil saturation .. or another explanation. I did a quick glance through this gentleman's PDF, and he compares Corolla filters but also has media measurements - they seem to vary between .021" and .038" so the .024" I observed is well within the range.
http://www.corolland.com/oil-filters.html
Originally Posted By: 440Magnum
And its shtuff like this that is driving me to pay the premium for synthetic wire-backed filters for EVERY vehicle at the moment.
Myself included, I'll go for a different MFG like Wix. But gauging from other's observations, Purolator filters are VERY popular which means this problem is widespread. And it's significant.
I won't do business with companies that produce substandard product, and it should be shouted from the roof tops until something changes.
I'd be interested to see an example of how the frams are more "wide-pleated." I suspect you are missing the characteristic of merit. What is critical is the mutual support of pleats against oil pressure (pleat downstream faces flat against each other; upstream faces irrelevant), and fully or nearly fully packing the pleat folds against each other at the center tube outer surface. Overall pleat density is not as critical, and the above construction criteria can be met with different overall pleat counts, as a function of media pleat thickness, fold thickness, and center tube diameter.
Originally Posted By: 440Magnum
Originally Posted By: NJC
I'm speculating here - but the problem could be weak media (numerous failures are possible) or lacking pitch uniformity at media to end cap bond. I haven't studied other filter designs enough to know if this is typical, but it looks like the pleats are too tight for majority of glue joint, and too wide near seam.
I agree with ZeeO that this is the best working theory. Where the theory comes apart a little (pun intended) is that if pleat uniformity were the only factor, then EVERY entry-level Fram-built filter (Orange can and clones) would do this, because they are far more wide-pleated in places than a Purolator Classic. Just speculating here, but maybe the Fram Orange Can's end caps made of filter media actually save it. Maybe its the stress of a flexible medium glued to a rigid metal end cap. Or maybe its the Classic media is softer than the cheapy Fram media.
I dont' think its just one cause, its at least two or more contributing factors coming together.
I think this is the correct, multiple causes. If I had to hazard a guess and pick a culprit, I'd go with weakened media. Not necessarily too thin (as per pictures above, the media from Bosch 3330 measure .6mm or .024") but too weak - either weak design or batch, or weakened with oil saturation .. or another explanation. I did a quick glance through this gentleman's PDF, and he compares Corolla filters but also has media measurements - they seem to vary between .021" and .038" so the .024" I observed is well within the range.
http://www.corolland.com/oil-filters.html
Originally Posted By: 440Magnum
And its shtuff like this that is driving me to pay the premium for synthetic wire-backed filters for EVERY vehicle at the moment.
Myself included, I'll go for a different MFG like Wix. But gauging from other's observations, Purolator filters are VERY popular which means this problem is widespread. And it's significant.
I won't do business with companies that produce substandard product, and it should be shouted from the roof tops until something changes.
I'd be interested to see an example of how the frams are more "wide-pleated." I suspect you are missing the characteristic of merit. What is critical is the mutual support of pleats against oil pressure (pleat downstream faces flat against each other; upstream faces irrelevant), and fully or nearly fully packing the pleat folds against each other at the center tube outer surface. Overall pleat density is not as critical, and the above construction criteria can be met with different overall pleat counts, as a function of media pleat thickness, fold thickness, and center tube diameter.
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