Side by Side: CHAMP PF48 vs ACDelco PF48

[Motorking]

Hello
The combo valve on the Champ filter works in a pretty cool way. The rubber adbv has a small lip that covers the smaller holes on the inner ring of the tapping plate. The durometer of the rubber is such that when the pressure differential is at the relief valve opening rate it will uncover the small holes to allow oil flow. It actually works very well in testing and does not leak unlike a well known competitors attempt at the same design. That said, the LS engines all have block mounted bypass valves anyway. The reason these filters have bypass valves in them is because the AC Delco and Ecore product lines are consolidated lines meaning these part numbers fit other applications that require a filter mounted bypass valve.
Nice write up BTW.

 

[Motorking]

That WIX combo valve leaks so bad the efficiency is barely measurable. The defect rate on Ecore filters is less than 8 parts per million.

 

[KCJeep]

Very interesting information Motorking.

Regarding ecores my buddy at work got one of those 8 in a million and lost an engine. It was replaced without hassle by Champ however. This was prior to any association with Fram.

 

[edhackett]

Originally Posted By: Motorking
Hello
The combo valve on the Champ filter works in a pretty cool way. The rubber adbv has a small lip that covers the smaller holes on the inner ring of the tapping plate. The durometer of the rubber is such that when the pressure differential is at the relief valve opening rate it will uncover the small holes to allow oil flow. It actually works very well in testing and does not leak unlike a well known competitors attempt at the same design.


Since durometer is temperature specific, measured at 23C +/- 2C, how does the valve compensate for temperature? How can the bypass value be the same at -25C and at +35C if the physical characteristics of the valve change with temperature?

Ed

 

[CapitalTruck]

Originally Posted By: Motorking
Hello
The combo valve on the Champ filter works in a pretty cool way. The rubber adbv has a small lip that covers the smaller holes on the inner ring of the tapping plate. The durometer of the rubber is such that when the pressure differential is at the relief valve opening rate it will uncover the small holes to allow oil flow. It actually works very well in testing and does not leak unlike a well known competitors attempt at the same design. That said, the LS engines all have block mounted bypass valves anyway. The reason these filters have bypass valves in them is because the AC Delco and Ecore product lines are consolidated lines meaning these part numbers fit other applications that require a filter mounted bypass valve.
Nice write up BTW.


Thanks for the great info! Question answered! My parents' local garage always puts Champ filters on their Highlander, this info will keep me from trying to dissuade them to use another brand.

 

[Sayjac]

Originally Posted By: edhackett
.....Since durometer is temperature specific, measured at 23C +/- 2C, how does the valve compensate for temperature? How can the bypass value be the same at -25C and at +35C if the physical characteristics of the valve change with temperature?

Ed

That's a question I'd like to see an answer to. Though much less technical it goes along with, as a nitrile adbv gets used and goes through heat and cold cycles and ages it will become less pliable and lose it's anti drainback ability. It's why silicone is used for mid to upper tier oil filter adbv's. Imo controlling bypass psi much more important than drainback.

Also one would think if the combo valve was so reliable GM would have just used it, same as Champ used previously for other makes with filter integral bypass. One would also have to conclude it is a less expensive design. As the new GM ACDelco ecore shows though, they choose and touted the new separate dome poppet bypass design. Everyone can draw their own conclusion as for the reason for that. I've drawn mine.

 

[ZeeOSix]

^^^ Yes, it would certainly seem like the temperature would effect the bypass function of the combo valve, especially when it's cold and at first start-up. Once the oil gets to normal operating temperature (usually around 200 F), then the operation of the combo valve could be designed to be pretty predicable when it opens up. Of course, running a combo valve that's made of nitrile rubber for too long could make it hard over time, which would seem to change its bypass operation some.

 

[Motorking]

Originally Posted By: edhackett
Originally Posted By: Motorking
Hello
The combo valve on the Champ filter works in a pretty cool way. The rubber adbv has a small lip that covers the smaller holes on the inner ring of the tapping plate. The durometer of the rubber is such that when the pressure differential is at the relief valve opening rate it will uncover the small holes to allow oil flow. It actually works very well in testing and does not leak unlike a well known competitors attempt at the same design.


Since durometer is temperature specific, measured at 23C +/- 2C, how does the valve compensate for temperature? How can the bypass value be the same at -25C and at +35C if the physical characteristics of the valve change with temperature?

Ed

Ed,
This is an excellent question and despite some of you calling me "filterking", I have no idea. Going to throw this at the Chief Engineer and will let you know what nhe says. Stand by.

 

[Motorking]

Originally Posted By: edhackett
Originally Posted By: Motorking
Hello
The combo valve on the Champ filter works in a pretty cool way. The rubber adbv has a small lip that covers the smaller holes on the inner ring of the tapping plate. The durometer of the rubber is such that when the pressure differential is at the relief valve opening rate it will uncover the small holes to allow oil flow. It actually works very well in testing and does not leak unlike a well known competitors attempt at the same design.


Since durometer is temperature specific, measured at 23C +/- 2C, how does the valve compensate for temperature? How can the bypass value be the same at -25C and at +35C if the physical characteristics of the valve change with temperature?

Ed

Ed,
Here is the response I got from engineering-
Durometer does change as a function of temperature. This is true for sealing gaskets and the combovalve. However, the amount of change is mitigated by the unique nitrile compounds developed for the combovalve. Combovalve material development required operation at -40F on the cold side to +275F. Bench testing confirms function at these two temperature extremes.
Hope that answers the question.