Why Upside Down Oil Filter?
 

Why does Mercruiser mount oil filters with the open end pointing down? I've tried searching for the answer but haven't found anything conclusive. I'm thinking of changing my remote oil filter to right-side-up to make filter changes less messy. Is there any advantage to upside-down? If not, why does Mercruiser do it?
---rick

I always wondered the same thing until I heard of the trick on here. When doing a filter change, loosen the filter slightly but do not remove it. Let it sit a few minutes. By venting it with the loosening, all the oil in the filter drains back into the pan and you actually wont spill a drop when you remove the filter. Works like a charm.

I would have said the open end down makes changes less messy because the filter will be drained? There's probably a more scientific answer relating to the flow of oil and catching 'dirties' in the filter but it's Mercury, so who knows........?

RR

Quick edit: Above post makes sense. Like it!

stab it with a screw driver on the bottom of the filter,which is up.:Dit drains nicely,,now the ones that are horizontal,they can get messy.

This is the trick I recommend too. In either filter orientation, they will spill oil when removed.

Huh. Now I'm jealous that mine is open end up, lol.

But you can fill yours up with fluid before installing it, so that evens up the score.

i was just wondering about that, lol. I guess you have to spin on the inverted units dry. Merc doesn't seem worried about it though.

Clearance ? in most applications there is something mounted right below the filter head

I`d rather have upside down, at least it drains out with a hole at the top .


Mine , not so much


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When I had that style I would punch a hole in top, then when you start to turn it have a cut washer fluid bottle under to drain into made a lot less mess, that style sucked!!

like ^^^

I'd feel sorry for you but my jealousy gets in the way. ;)

1) Always ensure you can spin the filter before you pop a hole in one. The last thing you want is a compromised filter that you have drained, that is stuck on the motor. Also, a filter that is full of oil is less likely to collapse when you really need to torque off a tight one.
2) You can drain an inverted one by poking a hole in the TDC, and IF you have an anti-drain back valve, you will need to pierce that too. Then let the oil drain back into the pan.
3) On a filter that is open end up, you can pop a hole in the /edge/end, and drain it out into a bottle that you can put a funnel on to decrease the mess.
4) You can also do the same on a side-mount filter. But you will have to put a finger over the hole as you spin it off.
5) You could also install pre-lubers and just push a button and walk away.

On those, I put a gallon sized zip lock bag over the filter, unscrew filter and let it drop into the bag.

I am cheap. I usually just double up two plastic grocery bags.

Padraig

Yep, works like a charm. No need to punch holes in the filter.

Because It make changing them so easy a cave man can do it.
1: Open hatch,
2: Take screw driver, punch hole in top of oil filter. Wiggle it back and forth.
3: Get out of boat, gather supplies,
4: Re board boat with oil change stuff. (The time gathering stuff lets the oil filter drain down).

Im down to 1 single shop towel to change oil both engines.

You loosen the filter to break the suction, it will drain the oil out - do not stab a hole in the filter as when you tear a hole in any metal object -- where does any of that portion of metal go --- hmmm maybe drain right back down with your motor oil then possible caught in one of your hose lines or where ever. . So do not stab oil filters.

The upside filters are because of clearance issues and better access plus some thoughts that the oil coming out of the filter flows better being upside down. I am not sure on that one. but it has been tossed around persay about the flow

like

Way I do it.

Me too. :champs: HAHAHAHA