that spring dealy in the oil filter bolt?

[dan filipi]

What's the purpose of it?

Pressure regulator?
Filter bypass?

If its a pressure regulator my thought is possibly could be the reason for my low oil pressure, maybe even "the infamous knock?"

 

[slabghost]

Filter bypass. There isn't any oil pressure regulator. If oil pressure is low either the oil pump is worn or passages are more open than they should be or both.

 

[roncar]

Bypass.

 

[dan filipi]

That diagram seems to be showing the oil path in arrows from the filter outside to inside.
That's opposite the discussion over at NGW which is what made me curious.

They're saying flow is from inside to outside and bypass is kicked in (done) by pushing the oil filter away from it's seat against the spring pressure around the filter bolt.
Wish I had a loose filter housing and bolt to look at.

 

[roncar]

IMHO,

1. all filters (air, fuel, oil) flow from outside thru the filter to the inside.
2. the filter does not move.
3. the spring is to insure the filter stays in the correct position while allowing for manufacturing tolerances.
4. I tried to explain this, but I'm no wordsmith. https://www.ngwclub.com/forum/viewtopic. ... 89#p377289

 

[dan filipi]

I don't have a filter bolt to look at so I imagine there must be a short section in that bolt exposed to oil and not covered by the filter which provides the path INTO the center of the filter bolt to do the bypass?

 

[mcgovern61]

I don't have a filter bolt to look at so I imagine there must be a short section in that bolt exposed to oil and not covered by the filter which provides the path INTO the center of the filter bolt to do the bypass?

Take a look:

 

[dan filipi]

Thanks, Gerry.

How much of the bolt is not covered by the filter?
Just trying to get clear in my head how the bypass works.

 

[mcgovern61]

The oil definately flows outside in. If you look at the bolt, the bottom hole is clear which allows oil to flow all of the time (otherwise the case would explode from pressure). The next hole up from the left (lower hole in picture) you can see the spring and in the next hole is the piston. The last hole to the right is where oil enters and pushes against the piston. It only opens when the pressure exceeds the spring pressure and allows full flow at that point. It is not easy to see in the picture, but the holes are staggered.

 

[mcgovern61]

Thanks, Gerry.

How much of the bolt is not covered by the filter?
Just trying to get clear in my head how the bypass works.

The entire bolt is covered by the filter except the threads and the hole at the bottom which again is the oriface that allows oil to flow all of the time.

 

[dan filipi]

But if the entire bolt is covered by the filter, (the entire bolt is inside the filter) where then does the oil outside the filter medium (oil at bypass pressure) enter in which to bypass?

I think I'm starting to confuse myself, Honey where's the Advil?

 

[slabghost]

Notice in the drawing the holes closest to the head of the bolt are outside the filter. Spring pressure closes those holes. Higher pressure pushes them open allowing oil to flow directly through the bolt bypassing the filter media. Even the bypass position some oil still flows through the filter. :rtfm:

 

[roncar]

Maybe these will help. The oil pump is directly behind the water pump and the orifice for the pump's output clearly goes to the outside the filter part of the oil filter housing. From the center bolt it goes up and to the right to lubricate the engine.

Using a washer to simulate the thickness of the filter cover (still too thin but gets the point across) the first set of holes are visible outside the filter and it takes me both hands to move the filter. I'm convinced the springs purpose is to keep pressure on the filter to keep the rearward filter gasket (around the bolt) pressing against the front engine cover, for a seal. That gasket is still riding on the threads, so it can't seal to the bolt.

 

[dan filipi]

Perfect, Ron. That 'splains it for me :thanks:

 

[AApple]

With every spin on filter I've ever dealt with, the oil enters thru the small holes around the perimeter of the top, and exits back into the engine thru the bolt/threaded nipple...from the outside in, if you will.
When the filter gets clogged, or there is enough pressure to unseat the bypass, the oil enters thru the outer holes, and goes directly thru the end & center of the bolt, which is uncovered, as you can see in the above pics.
When we were discussing ways to install spin on filters without having to spend $$$$ on adapters, I was shocked to hear that the bypass on these Wing engines would open at a seemingly low pressure...like 30psi or less. Next time I change the erl on mine, Imma gonna put a stronger spring in the bypass of the bolt. Before I do that, tho, Imma gonna put a mechanical oil pressure gauge on it, so I can see what the actual start up pressure is....I don't like the idea of the oil bypassing the filter on a cold startup..... :nea:

 

[mcgovern61]

With every spin on filter I've ever dealt with, the oil enters thru the small holes around the perimeter of the top, and exits back into the engine thru the bolt/threaded nipple...from the outside in, if you will.
When the filter gets clogged, or there is enough pressure to unseat the bypass, the oil enters thru the outer holes, and goes directly thru the end & center of the bolt, which is uncovered, as you can see in the above pics.
When we were discussing ways to install spin on filters without having to spend $$$$ on adapters, I was shocked to hear that the bypass on these Wing engines would open at a seemingly low pressure...like 30psi or less. Next time I change the erl on mine, Imma gonna put a stronger spring in the bypass of the bolt. Before I do that, tho, Imma gonna put a mechanical oil pressure gauge on it, so I can see what the actual start up pressure is....I don't like the idea of the oil bypassing the filter on a cold startup..... :nea:

In my video, I put an OP gauge on to see how the oil pressure reacts to throttle changes (and was looking for that pesky knock)
viewtopic.php?p=35636#p35636

When I started the engine, it was cold (but outside temps were about 72 degrees). At startup it was 15 lbs at idle.

Crank the throttle up to 3K (via the choke) and it went up to 55 lbs.

Leaned the bike onto the side stand and it dropped to 25 lbs at 2500K.

As the engine runs for a few seconds, the oil pressure drops off a bit. At idle on the side stand it dropped back to 10 lbs.

Pull the choke again to 2.5K at the oil pressure hovers at 19 lbs (still on the side stand)

Slowed the throttle to 2K and it maintains 19 lbs. Lean the bike back up while running at 2K and it comes back up to 30 lbs.

 

[rkthev]

With every spin on filter I've ever dealt with, the oil enters thru the small holes around the perimeter of the top, and exits back into the engine thru the bolt/threaded nipple...from the outside in, if you will.
When the filter gets clogged, or there is enough pressure to unseat the bypass, the oil enters thru the outer holes, and goes directly thru the end & center of the bolt, which is uncovered, as you can see in the above pics.
When we were discussing ways to install spin on filters without having to spend $$$$ on adapters, I was shocked to hear that the bypass on these Wing engines would open at a seemingly low pressure...like 30psi or less. Next time I change the erl on mine, Imma gonna put a stronger spring in the bypass of the bolt. Before I do that, tho, Imma gonna put a mechanical oil pressure gauge on it, so I can see what the actual start up pressure is....I don't like the idea of the oil bypassing the filter on a cold startup..... :nea:

But the bypass only opens if the filter is clogged and the oil cannot flow thru it. The oil will flow thru the easiest path, and as long as the filter is not clogged that will be thru the filter, and not the bypass valve. I would be careful of putting a stronger spring in and possibly defeating it. If the filter is clogged, the bypass needs to function even at lower oil pressures like at idle (like at the 10Lbs mcgovern61 measured above).

Take a look at the spin-on filter specs Randakk lists on his site. The bypass on most open at 8-11PSI.

https://www.randakks.com/Oil Filter Adapter Filter Fitments.htm
"The link referenced above is provided courtesy of Randall Washington, owner of Randakk's Cycle Shakk, LLC."