Oil filter bypass valve

[NHerron]

I've been wanting to discuss this for a while, still don't have the time to do a full post so I'll make it as short and sweet I can.

By oil bypass valve I mean the one located in the filter. Not the one that controls max allowable oil pressure for the engine located at the oil filter housing.
See this thread for a visual:
http://www.dsmtuners.com/forums/maintenance-repairs/433196-oil-filter-cut-away-fram-wix.html

It works off of pressure differential. I think an average bypass valves spring is around 14psi. 14psi as in if the oil filter media drops 14+psi because of a cold morning or a clogged filter, it will open up and bypass the oil around the media and send unfiltered oil out, to protect the engine from starvation.

A lot of us run with no balance shafts therefore a bit higher oil pressure than stock due to the one less path for oil to flow. Combine that with anything heavier than 5W-30 on a damn cold morning. That oil is not being filtered, including the turbos oil supply.

And its not like fluid flow is going to change between running balance shafts vs not. The pump will be driven at same RPM either way and fluids don't compress. So the filter takes the punishment. And who knows? How often does this oil get bypassed? People see higher than stock oil pressure at WOT all the time (AKA turbos spinning damn quick in possibly dirty oil!) so I wonder what we can do about that. There's a few filters that can fit and logically biggest is best (like an air filter -less pressure drop when there's more available area) but I wonder if biggest available is still not big enough, plus we all hate a giant oil filter unconvienently close to the hot o2 housing. Make that a stainless housing for me

For now, I've been running the FP oil filter/restrictor to aire on the safe side.

Hopefully this is an eyeopener to the people that really want to be 100% about every angle to their hobby car builds. I know some will say things like "well I've been fine for xx miles" "it hasn't happened enough to cause for concern" etc etc. I understand that. This is aimed for the people that meticulously mold their car into exactly how they want and not just bolt parts on (no offense, really)

Thanks for any input

 

[donniekak]

I've been wanting to discuss this for a while, still don't have the time to do a full post so I'll make it as short and sweet I can.

By oil bypass valve I mean the one located in the filter. Not the one that controls max allowable oil pressure for the engine located at the oil filter housing.
See this thread for a visual:
http://www.dsmtuners.com/forums/maintenance-repairs/433196-oil-filter-cut-away-fram-wix.html

It works off of pressure differential. I think an average bypass valves spring is around 14psi. 14psi as in if the oil filter media drops 14+psi because of a cold morning or a clogged filter, it will open up and bypass the oil around the media and send unfiltered oil out, to protect the engine from starvation.

A lot of us run with no balance shafts therefore a bit higher oil pressure than stock due to the one less path for oil to flow. Combine that with anything heavier than 5W-30 on a damn cold morning. That oil is not being filtered, including the turbos oil supply.

And its not like fluid flow is going to change between running balance shafts vs not. The pump will be driven at same RPM either way and fluids don't compress. So the filter takes the punishment. And who knows? How often does this oil get bypassed? People see higher than stock oil pressure at WOT all the time (AKA turbos spinning damn quick in possibly dirty oil!) so I wonder what we can do about that. There's a few filters that can fit and logically biggest is best (like an air filter -less pressure drop when there's more available area) but I wonder if biggest available is still not big enough, plus we all hate a giant oil filter unconvienently close to the hot o2 housing. Make that a stainless housing for me

For now, I've been running the FP oil filter/restrictor to aire on the safe side.

Hopefully this is an eyeopener to the people that really want to be 100% about every angle to their hobby car builds. I know some will say things like "well I've been fine for xx miles" "it hasn't happened enough to cause for concern" etc etc. I understand that. This is aimed for the people that meticulously mold their car into exactly how they want and not just bolt parts on (no offense, really)

Thanks for any input

It operates on a pressure differential, not total pressure. So you can have 100 psi of oil pressure, and as long as the filter itself is less than a 15 psi restriction, it won't open. They are designed that way in case of a clog.

 

[NHerron]

Funny, just like I said in my 3rd paragraph.

It works off of pressure differential. I think an average bypass valves spring is around 14psi. 14psi as in if the oil filter media drops 14+psi because of a cold morning or a clogged filter, it will open up and bypass the oil around the media and send unfiltered oil out, to protect the engine from starvation.

Not being a jerk here really, but Google it and see what I mean if you don't see my angle.

 

[NHerron]

Guys any thoughts?

 

[donniekak]

Funny, just like I said in my 3rd paragraph.


Not being a jerk here really, but Google it and see what I mean if you don't see my angle.

As long as the pressure across the filter isn't greater than the set pressure, it stays closed. As I said, total oil pressure can be 100psi, and the bypass stays closed.
I see your angle, it's just not correct.

Funny, just like I said in my 3rd paragraph.


Not being a jerk here really, but Google it and see what I mean if you don't see my angle.

You can increase the total pressure to 150 psi, and as long as the drop across the filter is less than the bypass spring pressure, it stays closed.

 

[NHerron]

Reviving this.

For all stock DSM's but mainly modified-

What makes you think the filter is built to pass that volume of oil? When you hit the key, the starter can draw 500+amps for a split second then stabilize around 100.

Even in stock vehicles, the bypass valve is open more than you think. IE- WOT, cold mornings, thicker than stock oil- even more opportunities.

If I'm making this stuff up, well that would mean I'm nuts. Nuts AND gullible for believing when people reveal the shit their turbo inline oil filter catches. Filter media won't pass that debris, no way. That stuff only passes when the valve is open.