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Is this gap normal for oil filter?

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206
403
Exp. Type
HPDE
Exp. Level
Under 3 Years
Chicagoland
I have a boss 302 “oil cooler” on my engine block and it requires the FL820 Ford Racing oil filters. Have done a half dozen oil changes the last year between track days and never noticed this gap until today. It has me worried but I think I’ve just never seen it at this angle. The threads are perfect, goes right on like normal, and as soon as the rubber gasket makes contact it becomes harder to tighten which is completely normal. However, the lip of the oil filter does not touch. There is a gap between the edge of the filter and the cooler/housing.
I tried two new filters to be sure, and the old one, and they all have this gap. Did I just not notice it before? Started the car and revved it and no drips. Just concerning.

I am 100% certain the old gasket came off with the older filter, and that it’s not a double gasket issue on the filter or housing.

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I just installed the same filter for the first time and mine looks similar. The lip of the filter housing is slightly outside the sandwich plate but the gasket is in full contact with the plate a little inside the edge. So there is that little gap. Let the car idle a few minutes twice and no leaking but the track will put it to the test next week.
 
I just installed the same filter for the first time and mine looks similar. The lip of the filter housing is slightly outside the sandwich plate but the gasket is in full contact with the plate a little inside the edge. So there is that little gap. Let the car idle a few minutes twice and no leaking but the track will put it to the test next week.
Good to know yours looks similar. I’ve been driving it the last hour around town and can confirm it’s not leaking…. I think that might just be the way it sits after all.
 
Think of it this way - if you were able to screw the filter on so that the edge of the can was in contact with the mating face, how would you know if the o-ring had enough compression on it to seal properly when the can made contact? The standard "finger tight and 3/4 turn" tightening couldn't be done with metal-to-metal contact taking place before the 3/4 turn is done. With no metal-to-metal contact during tightening, the 3/4 turn is guaranteed to compress the o-ring by 0.75 * (1/thread per inch) inches.
 
Think of it this way - if you were able to screw the filter on so that the edge of the can was in contact with the mating face, how would you know if the o-ring had enough compression on it to seal properly when the can made contact? The standard "finger tight and 3/4 turn" tightening couldn't be done with metal-to-metal contact taking place before the 3/4 turn is done. With no metal-to-metal contact during tightening, the 3/4 turn is guaranteed to compress the o-ring by 0.75 * (1/thread per inch) inches.
Because on filters where can contacts seal is sticking out. On those you have to actually over tighten them to contact, when tightened correct can just about touches.
 

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