WETTE VETTE

You should use a high pressure filter that has extra capacity if you plug it. I know K & N makes one. I have always left the stock Merc set up as is with no problems. It is really whatever you want to do.

US1 Fountain

The conscern as I see it, is not relieveing access pressure, which is what you are stating above. The thing is, that if you plug the bypass valve and then by some wild chance have a filter get plugged, you now have a motor with no oil flow. My guess is that is a bad thing. Sure, your pump is still pumping away, but not moving any oil. It has no where to go. Just spinning it's tires.



My HP motor had the bypass valve. So wouldn't put to much merit in the Merc brochures. Many errors in them.


Recall GregP's oil filter troubles?.............. where a small amount of water got into his oil and swelled the filter elements shut, starved the motors of oil. Not only 1 time, but more.

The Question is:
Do you have more to gain, or more to loose by eliminating the valve? It's there for a reason.

Keep in mind, you are working with a marine motor. Not many of these are operated in dusty conditions, so why the thinking that all the oil needs to be filtered?


You mentioned this is a 7.4 , I'm assuming not some 800 hp motor. Why change a proven thing?

It's your dime.
Don't you hate it when you ask a question in hopes of getting an answer, only to have it create more questions?

formula31

hehe yea, its not a 7.4 any more, just the adaptor. oh well, Im gonna plug it for break in and then put the relief back in after 20 hrs or so, I figure thats the best of both worlds. I filter out all the breakin crap and any left over garbage from the rebuild and then back to the relief for safety.

traviss

I had a problem with high oil temps. We assumed that the oil was taking the least restrictive passage, which was through the bypass and not going throught the remote oil filter, oil cooler, and oil thermostat. I was kinda of second guessing the idea of doing away with the bypass, so I called and talked to tyler crockett and he said on most of his motor's he build's, they plug the bypass and run high burst filters. So I welded up the bypass in my stock merc unit and run a fram HP4 filter now.. My oil temps are alot better now, plus the engine will never get unfiltered oil now.. Plus I change oil every 15 hrs, So a plugged filter is a think of the past. If anybody gets a plugged filter in this short of time, you have alot more to worry about then oil pressure. I know if the filter plugs up it will not get any oil pressure, just gotta watch the gauges and keep on top of things.

GregP

Just my experience but ... I had a rash of oil filter problems due to the condensation moisture causing the filters to stop flowing completely. I would have 75 psi going into the filter housing and 0 psi coming out (since I have no pypass). ALL paper element filts that I tried did the same thing.

I personally am certain that almost all marine motor oil filters stop filtering long before you would ever expect and run all your oil through the bypass, as with the very low engine op temps you do get condensation buildup which kills the filters very quickly (my record minimum time on a filter before failure was was 10 minutes at idle on the first start of the season).

There are two known solutions to this problem. One is run only synthetic media filters, ie Wix Racing. The other, which I use, is run cleanable filters (I am using System 1 units).

Prior to switching to the System 1 filters I had filter shut-downs with AC filters, FRAM filters and K&N filters. Since switching to the System1 filters I have had no problems, have seen not signs of moisture in the filters when cleaned (although I still see some condensation evidence if the motors aren't run hard enough and long enough to get the oil temp over 200* for at least 10 minutes).

The system 1 filters do have an internal bypass, but my assessment from checking the media and feeling the pressure needed to open the bypass (which is much more than a stock GM filter adapter bypass) is that the filters have porobably never used their internal bypass.

And I have not had one suddden, total loss of oil pressure on the "out" side gauge since.

my $0.02 - Greg

WETTE VETTE

GregP,
If a majority of the filters stop filtering before they are changed and are operating in bypass, wouldn't the oil temps increase? I have my temp sender in the pan and have never seen an oil temp increase even right before a oil and filter change. As a matter of fact I randomly check the oil cooler for heat and it is located after my filter in the flow path and it is always warm from the passing oil. Running properly sized lines and fittings makes a huge difference with flow capacity. Also this is another reason to stay away from 50 WT oil. There aren't to many on the board from my experience who need more than 10W30 or 10W40 wt. oil.
The filter I run is a Fram PH8A and Amsoil 10W40 Synthetic, all -10 oil lines with no sharp 90 degree fittings. Something else to ponder is that some filters have a built in bypass. Right??

bobby daniels

Alot of good thought here from travis ect. ,,, please think about
just looseing a lifter roller !! once something this small happens the bypass will stop the filter from working and their goes your bearings ect. ,,,unless the bypass is pluged then your safer ,tons safer .
Everyone I know uses a super good oil filter so that or not changing oil should not be a problem as we all take care of our motors,if not we would not be worried about the bypass !!!!!!

But just to take care of your motor WARM THAT OIL ,and block the bypass !!!!!
THIS IS REAL WORLD

GregP

My coolers are in the bellhousing so I can't check them for heat. I do have gauges on both inlet (mechanical for checking pressure while in the engine bay) and outlet (electric for the dash reaout) side of the filters so I could easily see where the pressure went away and flow stopped. In normal use there is a 10-15 psi drop across the papers filters (when not stopped completely that is), the System 1 filters show 5-10 psi drop across the filter housing. The amount of water required to stop the filter element from passing oil was low enough that even cutting the elements open you could not "see" any moisture, let alone any "milk".

As to filters with an internal bypass, "GM" application filters usually don't, many "Ford" application filters do. Don't know where Mopar apps are.

-Greg

formula31

Ah Geez, do you think just once I could ask a question that had a clear cut answer? I suppose then I wouldnt be asking huh?

CESSNA

I've had alot of experance with this in racing and I would block or not use it at all on anything I care about