oil filter theory and questions...

[karolko]

i was wondering if someone could explain to me what 3 things on filters as i am looking into running a remote oil filter mount and thus searching for the type of filter i want to run

1) anti drain back valve: in my particular scenario i will be mounting the oil filter vertical, but does this really mean than there is a check valve in the oil filter that will not allow oil to drian out backwards from the filter once the motor is off. When is there a benifit to having this feautre on a filter.

2) by-pass valve: I am under the impression that this means the if the oil filter sees more than "X" psi then it will bypass some oil and send it back to the motor UN filtered. Is that correct? Sounds like a big no no to me.


3) micron size. I am currently looking at WIX filters and their racing versions seem to have 61micron size yet their stock wix filters (like the 51258 that RJC recommends for his biggie filter setup is 21 micron. I am under the impression that the smaller the micron size, the better, but i am sure there is a limit. Can someone elaborate.

I really hope this stuff helps other people and not just myself.

Thanks alot in Advance

Adrian

 

[wantattype2]

1) anti drain back valve is used in the oil filer when the filter is mounted at an odd angle like the V6 or V8 buick engine.
2) You are correct when the filter goes into bypass this keeps the engine from starving for oil, a good filter like the Wix or Napa Gold uses a spring to return to the filtering mode when the pressure returns to a lower pressure.
3) On the racing filters the filter media is a larger micron size to allow more oil to pass thru the filter with out putting the filter into bypass, this becomes more inportant with heavy weight racing oils or high rpm engines.

 

[earlbrown]

The misconceptions on oil filters and why they do what they do will probably always be misunderstood.

If you're mounting the filter vertically you don't have to have an antidrainback valve. If you have one it won't matter at all.

The filters internal bypass is nothing more than a spring the holds the filter cartridge against a seal. When seated all the oil goes through the filter media. It's not oil pressure that opens the valve it's a pressure difference that does it. Lets say the filter has a 10#spring in it. You have 40PSI and 5#'s of pressure drop. In that case the spring would be open halfway. Depending on the micron size and square inches of media, you might have 90% bypassed and 10% filtered. At that same opening with some miniscule micron rated filter, the pressure drop would be greater so the amount being bypassed would be greater. At the same time the filtered part would have the hell filtered out of it. (some uber micron filters can filter out some of oils necessary additives). There's only 6qts of oil in our engines (1.5gallons) and our pumps move a buttload of gallons per hour. Even at a 5% filter rate all the oil is going to get taken care of fairly quickly and fairly often.

Now the knee jerk reaction to some people is to say "OMG, I need to start plugging bypasses, unfiltered oil is the Debbil, Bobby Bushay!". There's several reasons that's unnecessary and counterproductive.

First any filter media you blow through is going to cause a pressure drop, period. If you force every drop of oil through a streetcar filter it's going to cause a greater pressure drop. In order to maintain pressure the pump has to overshoot the desired pressure by the exact amount of drop caused by the filter arrangement. If a filter causes 20PSI of drop and you want 60PSI, the pump now has to make 80. More parasitic drag, more load on the timing chain, more load on the front cam bearing, more heating of the oil and more beating up on the oil, less gas mileage, etc... We'll call it 'less efficient'.

As a secondary "benefit", filter's orifices get smaller as they get used. A micron sized hole with a 1.25micron jagged piece of crud will block the old leaving (5) .02micron holes around the perimeter. (the EXACT reason filters have bypasses in them)


The other common statement I see to justify 'upgrading' an oiling circuit to a non-bypass system is "I don't want the crud in the bottom of my oil pan to get pushed into my engine". For that logic to be valid, you'd already need a rebuild, not an oil change. If there's crud in your engine, it's already blown.



Opinions vary and contents may settle during shipping... but personally I'll take a shitload of 'dirty' oil (that really isn't dirty) over very little 'clean' oil any day of the week. My engine building philosophy is that I'd rather oil the hell out my bearings then smoke them because every drop has to be filtered.


For comparison's sake the loosest bearing in my personal engine is .0009". I run a stock pump (with the weakest spring) in a stock timing cover (with all the earlbrown mods) with a long stock Wix, Mobil1, or Pure1 filter (depending what store I'm at) with no cooler. It works so well I don't bother to run an oil pressure gauge and my idiot light goes out before the engine busts off.

 

[Nick Micale]

I know the subject of this thread is "Oil filter theory and questions", but I rather put my trust in real-world experience and knowledge than opinions what the ad people write.

This forum is about a 50 year old engine design being taken to performance levels never imagined, not our new daily driver.

When done properly the stock V-6 oiling system is more than capable of providing a more than adequate supply of oil as needed when done properly.

If a bypass is used in an oiling system, especially in a performance engine, that is not what I could accept? The only reason a bypass is used because the $2.00 oil filter is too restrictive and the filter media not able to pass enough oil.

I am also not interested in a piece of paper, or what ever they choose to put in for filter media, to protect my very expensive engines. I have experienced 2 serious failures with this type media.

First issue is the very fine, small micron, filter media will quickly become in-effective in many areas that clog up and can even cut off oil flow completely.

Second, the filter will also develop "tracks" that will pass lots of oil without filtering it at all?

This info is not an opinion or guess, it is based upon the MANY filters I have cut apart and examined. My conclusion of the paper, or whatever is used in commercial filters, cannot be uniform in its ability to provide 100% filtering as stated by their specs.

Like was stated above, race filters like Wix have better flow as the micron size is about 60 vs. 10 in some filters.

My personal answer to this situation of what oil filter to use is the re-useable mesh filter that has been used for years on very expensive engines and machines.

Not only do you have a filter with no bypass and not way possible for it to develop "tracks", it is always a true 40 micron filter. So not only do the get the best possible oil filter, it is free!

OK, nothing is free, but after 2 seasons of racing, my filter purchases of zero, recovered the initial investment, and I no longer have to buy filters. Since it is cleaned at every oil change, I also know if any foreign material is present.

 

[coach]

Nick,
Are you talking about the cartridge type filters like TR Custom parts sells? I was considering one since I am well over 15k on my engine build.

Thanks

 

[turbobitt]

I been using the System 1 reusable filter with hood success. Very non restrictive and easy to inspect during oil changes.
AG

 

[TR Custom Parts]

Coach, ones we sell have a replaceable synthetic fiber element housed in a stainless steel cage. Easy to inspect by unrolling the element. Elements have to be replaced though. Filters down to 8 microns. No bypass in it. Does have a drainback valve. They have been making them for almost 30 years now. Factory is about 10 miles from my house. http://buickgn.com/billetoilfilters.html

 

[coach]

Coach, ones we sell have a replaceable synthetic fiber element housed in a stainless steel cage. Easy to inspect by unrolling the element. Elements have to be replaced though. Filters down to 8 microns. No bypass in it. Does have a drainback valve. They have been making them for almost 30 years now. Factory is about 10 miles from my house. http://buickgn.com/billetoilfilters.html

I'll grab one for the new engine. Any other color?

 

[TR Custom Parts]

Any color you want as long as it is blue. Sort of looks like the blue of the stock ac/delco filters

 

[ek02]

Nick uses the K&P Engineering filter according to some posts on this site.

 

[olddog]

I've used "O Berg" type filters for over 25 yrs on various
cars, with great results.

 

[Pronto]

Interesting design. Never seen those...

 

[GARY HARVEY]

Early on, most engines had no oil filters . Chevrolet (1955) offered the option of the partial flow canister ($18.00 if my memory serves me). It was standard practice that changing your oil got [you] far enough not to be concerned, then again, the car builders did not have engine mileage dictated to them. Lots of cars with lots of miles was witness to not being concerned with filteration. As for the early racers, if engines lasted the complete race they were rebuilt (over & over, etc..).

The stuff done on the Beach (back in the day) is witness to filters not being a concern. The first filters were added to collect the sand from the casting process (in the mid 50s) when GM started having issues with the small blocks (not from the sand on the beach). It was a couple of years before the "full flow" filter appeared in mid 57' with the "283" and they have been in place ever since.

If you are concerned about by-passed and unfiltered lubrication, a filter bank with how ever many you care to use works well.
I do suggest using a in-line screen on the inlet side of plumbing system to collect pieces before they pass through the pump when you fail to keep a eye on the bottom end.

If you get a (good) amount of miles on a performance engine, you ain't at the track enough.
There are more than a few Buicks around with stock oiling systems getting excellent mileage between rebuilds.

 

[Nick Micale]

Nick uses the K&P Engineering filter according to some posts on this site.

When I changed from a race filter to the K&P, my oil pressure increased 5 psi and MPH was up from 135 to 136!

 

[vacuum 6]

I have Mark's older style design gained ~5 psi at idle and WOT. Worth every penny.

Coach, ones we sell have a replaceable synthetic fiber element housed in a stainless steel cage. Easy to inspect by unrolling the element. Elements have to be replaced though. Filters down to 8 microns. No bypass in it. Does have a drainback valve. They have been making them for almost 30 years now. Factory is about 10 miles from my house. http://buickgn.com/billetoilfilters.html

 

[dr_frankenstein]

Early on, most engines had no oil filters . Chevrolet (1955) offered the option of the partial flow canister ($18.00 if my memory serves me). It was standard practice that changing your oil got [you] far enough not to be concerned, then again, the car builders did not have engine mileage dictated to them. Lots of cars with lots of miles was witness to not being concerned with filteration. As for the early racers, if engines lasted the complete race they were rebuilt (over & over, etc..).

The stuff done on the Beach (back in the day) is witness to filters not being a concern. The first filters were added to collect the sand from the casting process (in the mid 50s) when GM started having issues with the small blocks (not from the sand on the beach). It was a couple of years before the "full flow" filter appeared in mid 57' with the "283" and they have been in place ever since.

If you are concerned about by-passed and unfiltered lubrication, a filter bank with how ever many you care to use works well.
I do suggest using a in-line screen on the inlet side of plumbing system to collect pieces before they pass through the pump when you fail to keep a eye on the bottom end.

If you get a (good) amount of miles on a performance engine, you ain't at the track enough.
There are more than a few Buicks around with stock oiling systems getting excellent mileage between rebuilds.

exactly, like multiple filters right?

if one is too much pressure drop, the 2 should improve that situation and make the amount of oil filtered occur faster then it would with one right?

 

[earlbrown]

2 filters in parallel would decrease pressure drop (everything else being equal). 2 filters in series would hit you twice.

 

[dr_frankenstein]

2 filters in parallel would decrease pressure drop (everything else being equal). 2 filters in series would hit you twice.

he he he.......... stilll double checking that....