How important is it to match-up bypass relief valve psi spec to OEM oil filter?

[LoneRanger]

So Moto Guzzi uses UFI 23.287.00 as the OEM oil filter on their big block v-twins (1151cc i.e. "1200"). The 23.287.00 has a bypass relief valve pressure spec of 1.2 bar which equates to 17 or 18 psi. AFAIK, none of the after market filters have that high of an opening pressure threshold spec, most are about 8 - 11psi. Moto Guzzi also specs 10W60 motor oil.

Should I be concerned about an after market oil filter going into bypass too often on cold starts? Just bought a HiFlo Filtro HF551 . . .

 

[Danno]

While under warranty, I use OE filters. One less variable to worry about if something goes wrong with the engine and you need warranty coverage.

 

[Rand]

Subaru had a similar issue oem filters were 23 psi aftermarket around 11psi.

I used oem filters, although in that case there are some aftermarket alternatives now.

 

[Kira]

I believe the importance of matching a designed bypass pressure is two-fold.

A filter with bypass pressure too low will wash a percentage of the pumped oil over the dirty side of the filter material and recirculate it unfiltered.

A filter with too high a bypass pressure will run the risk of higher pumped oil pressures possibly damaging the filter material.

Someone posted here that the second scenario (bypass setting too high) won't damage filter material because the pressure on both sides of the material is essentially the same.

I don't know.

 

[zorobabel]

What about too high of a bypass setting starving the bearings of oil? Is this ludicrous?

 

[Truckedup]

Originally Posted by zorobabel
What about too high of a bypass setting starving the bearings of oil? Is this ludicrous?



If all the variables stacked up against you, yes...Just how can anyone know exactly how accurate the bypass opening PSI is? You can't....

 

[ZeeOSix]

Originally Posted by Kira
Someone posted here that the second scenario (bypass setting too high) won't damage filter material because the pressure on both sides of the material is essentially the same. I don't know.


There's a delta-p across the media ... that's what makes a bypass valve open up. If a bypass valve is set to 23 PSI for instance, it will open when the delta-p across the media is 23 psi.

In that case, the media better be able to take that much delta pressure across it.

Filter bypass valves are set based on a variety of factors, including the design of the filter media's flow performance.

If a bypass valve is set too low it could bypass more often, especially if the engine is revved high with cold oil (not wise to do anyway). If the bypass valve is set too high it could cause the oil pump to hit pressure relief sooner, and therefore the oil volume going to the engine will be cut down some when the pump hits pressure relief. The higher the pump's pressure relief setting, the better in regards to having a filter with a high bypass valve setting.

 

[ZeeOSix]

Originally Posted by LoneRanger
Should I be concerned about an after market oil filter going into bypass too often on cold starts? Just bought a HiFlo Filtro HF551 . . .


Is there a spec from HiFlo on what their bypass valve is set at?

 

[CT8]

Buy the oem.

 

[02SE]

I've used lots of HiFlo Filtro filters with no issues. At one time (and possibly still the case) they and the OEM Suzuki filters were exactly the same filter.

 

[LoneRanger]

Originally Posted by ZeeOSix

Is there a spec from HiFlo on what their bypass valve is set at?


I asked that question on their Contact Us form. Reply from HiFlo rep (underline emphasis mine):

"...we have all our filters third party tested by TUV of Germany and certified by them to be a suitable replacement for the OE. If fact, TUV's minimum standard for this certification is the spec of the OE filter so the HF551 is certified to be a direct replacement. We are the only manufacturer in the world with this certification on all our filters. When you buy our filter, you are not getting a "close enough" filter, you are getting a direct replacement that is third party certified to be correct (look for the blue and white TUV logo on the box)."

 

[kballowe]

I use those HiFlo filters on my three Moto Guzzi motorbikes.
No issues.

 

[barryh]

Originally Posted by Kira
I believe the importance of matching a designed bypass pressure is two-fold.

A filter with bypass pressure too low will wash a percentage of the pumped oil over the dirty side of the filter material and recirculate it unfiltered.

A filter with too high a bypass pressure will run the risk of higher pumped oil pressures possibly damaging the filter material.

Someone posted here that the second scenario (bypass setting too high) won't damage filter material because the pressure on both sides of the material is essentially the same.

I don't know.



No question that a filter can be damaged by excessive pressure. It's a very rare occurrence but it's been happening to BMW flat twins for the last 40 years. The combination of a high output oil pump, very cold temperatures and excessive revs will do it.

Here's the core out of one of mine which just happened to be a HiFlo.

 

[LoneRanger]

Originally Posted by kballowe
I use those HiFlo filters on my three Moto Guzzi motorbikes.
No issues.



I ended up going with the HiFlo filter that cross references to the OEM. Seems to be a very well built filter, from the outside anyhow. The gasket was pre-oiled with plastic wrapper applied to it, which was a nice extra. Hopefully it doesn't seep at the gasket like the OEM filter I used last time did.

 

[troop]

I recently picked up some syn oil at my local Walmart, and was oh so close to grabbing a ST6607 oil filter. Paused a bit and thought. Decided the extra few $ on my tried/true HiFlo's is well worth the peace of mind. IIRC, Champion Labs changed the design of the relief valves, hence my reluctance.

 

[DoubleWasp]

KTM LC4 engines with the long cartridge filters are pretty good at crushing them too. Definitely does happen. Mine with the short cartridge filter and secondary spin on filter on the frame (PH7317 size) suffers no issues.

 

[ZeeOSix]

If a filter is getting crushed from too much delta-p, then the bypass valve is ineffective. One of the purposes of the bypass valve is to prevent filter damage when delta-p gets too high.

The bypass valve setting is somewhat dependent on the filter's physical properties, like the strength of the media and center tube, and the level of flow restrictiveness of the filter element. The other factors that determine the bypass valve setting is the engine's oil pump max volume output and the oil viscosity used. So what the means is you may see 10 different brands of filters all specified for the same exact engine, but their bypass valve setting may be somewhat different. Therefore, you can't focus solely on finding a filter that has the same exact bypass valve setting as the OEM filter, or some other reference filter.

 

[berlyn]

Yes but it can damage the oil pump from too much stress? I don't know either.

 

[ragtoplvr]

I do not think the old BMW twins have a oil filter bypass. IMHO The filter on them is a horrible kluge anyway.

In fact oil pumps can be damaged by too high a pressure. They can wear the drive gears. They can split covers.

Rod

 

[berlyn]

Mmm this reminds me a horror story once my mechanic told me about a Hayabusa- engine failure due to a cheap oil filter. I don't know the brand. Must have been oil pump gears. Terrible.