I consider that 'blind' faith. I'm glad you KNOW the flow capacity of that filter. Amsoil wouldn't give ANY info on their filters to me.

MY suggestion is......don't do it! Been there, done that, BEFORE I knew about that segment of the oiling system. :) Get yourself a filter capable of the flow the pump will generate, and leave the bypass alone. The higher the capacity of the filter, the less that differential valve will need to open. You live in Ohio. I trust you will not start that engine with cold oil in the pan.

http://www.threadsdev.com/forum/grae...rary/shrug.gif Do what you gotta do.

BTW, what did Amsoil tell YOU, as to their filter capabilities? I trust you inquired.

What about this...does anyone make a adaptor with a bypass that has a stiffer spring in it? Something that would require a few more PSI to open it?

BTW I never talked to amsoil, suppose I could try that see what they say.

I'm an Amsoil dealer (I sell only to myself and became a dealer jsut to get the better discounts on synthetic oil) and their filters are designed to filter out smaller particles than your typical parts store oil fiter. Meaning, smaller holes. Does that reduce flow capacity? Not sure, but all things being equal, I bet it does.

With your conmnections, is it possible to get actual printed info on their filters? I've inquired with their engineers, and got little more than foolish 'say nothing' layman talk, and a round around. Why they insult my intelligence, by stating alot of nothing, is beyond me. :( Not the first filter mfr. to do so, but nonetheless, don't understand the secrecy.

The info I am referring to, is flow capacity at various temps, and the influence it has on activation of the bypass differenial. Something similar to what AC/Delco has on their site. Amsoil refused to submit this info to me.

I used to buy amsoil had a fleet account and was also a dealer, used series 200075/90 in my posi and it failed do not put faith in any amsoil product. Multi level marketing thats all just like amway.

GM makes an oil filter listed in ther perf parts cataloge, its full length. An oil filter is too important to trust anyone else, used a fram and the pleats folded over ( I opened it up ) will only use GM filter from now on.

John Carpico

AC Delco filters are known on average to be pretty good. There were some issues with mexican made PF35L's from a few years back, but I havn't heard anything bad since.... however...

Isn't it strange that AC Delco contracted Champion Labs to make their black-label "Ultra Gold" oil filters a few years back? The UPF filters have been discontinued to my knowledge, although they received outstanding reviews when they were available. They had the smallest filter size of any that advertises, and several oil filter reviews online listed them as having the highest pressure capasity as well. I picked up a 6-pack of them a few years back (last one is on the car right now :() and have to say I was REALLY impressed. I've never seen/held such a sturdy filter. The teflon-lined silicon seal, 8 micron filtering, and 190+psi capasity (along with an internal bypass valve and the UPF1218/UPF35L size) was quite impressive.

The same sources listed Champions Labs as making their own brand filter, and suppliing the filters for Mobil 1 and K&N. These three however only filter to the now-industry-best of 10-microns... but come in the same sizes, have just a durable containers (although supposedly the metal filter-element-supports arn't as bomb-proof as the Ultra Golds were), bypass valves, and theK&N even adds a nut on the bottom for those times they seem cooked on.

When using my Ultra Gold filters I found the oil pressures (with Mobil 1's 10W30) were about 10 psi higher than the stock PF1218 (with 28 to 30 micron capasity).

For the same size filter (which should be as large as you can fit), a larger filter element will reduce pressure, but higher filtering capability (smaller size holes), means more pressure.


I would imagine that the pressure increase from the filter element would in fact increase the pressure differential the bypass sees. Better Mobil 1 and K&n filters are a step in the right direction, but with a limited amount of space under the engine I think the best alternative is a remote oil filter that you can make as big as you want. Tieing in an oil-accululator while your at it wouldn't hurt (in line with the filter, or using one of those trick 2-port filter adapters). :)

For example:
http://www.cmfilters.com/
http://www.s1filtrationgroup.com
http://www.parker.com/racor
http://www.vortexfilter.com

Here's some info on Amsoil's oil filters, although I just don't buy the part about .1 micron filtration... there must be a serious pressure/volume step-down in place for that to happen... but who knows, it might be legit. http://www.amsoil.com/products/bf.html

hmmm... 10 micron limit for most filters @ ~60psi they flow anywhere from 9 to 34 gallons/minute.

.1 micron = 100 times smaller holes


2 times/hour? :) ok...

10 quarts/hour = 2.5 gallons/hour
2.5 gallons/hour = 0.042 gallons/minute (~1% of standard flow)

hmm.. I guess that adds up... assuming the statement from Amsoil is correct. That would explain how they dropped the pressure in the bypass filter (they didn't). Looks like a metering block that just relies on the back pressure differentials in the filter elements to divy up the oil flow rates. Cool concept really...

I wonder if it works. How do they stop the .1 micron filter from getting clogged with large particles? The filters can't possibly be in-line with each-other are they? If they are in a parrallel design, how do they stop the filtered large particle sludge from getting to the .1micron filter and clogging it?

hmmm... maybe the large filter output is in parrallel with the .1micron filter inlet, with a comparable restictor hole to keep pressure up on the .1 micron filter element.

I'm sure this is the first time I've seen two-stage filtering on a car. hmmmmmmm....

I have heavy equipment and have seen huge differeces in different filters. The media used and the amount of media determains how restrictive a filter will be, a higher quality media can be less retrictive and filter smaller particals at the same time.

The oil pressure guage reads after the filter so if it can't get throught the filter you will see it on the guage.

I checked the part # of the GM filter i've been using it is a PF35L, what are the issues whith the filter should I be concerned. The volume of oil filtered must be OK since I see good pressure.

I havn't done oil analysis on cars but on the heavy equipment I used a good oil with a bypass filter (kleenoil england) on a separate circuit. At 500 hours (like 15000 miles) the oil still had 70% of the additive package and had 50% allowable contamination.

On a car that sees limited use between oil changes a bypass is overkill and that amsoil filter is just BS :alert:

My only concern is finding a good filter who can you trust without actually testing in a lab

John Carpico

Let me guess, Fram? We nearly junked one of our super (low) budget race motors last year because of one. Slapped in a cheapie AC and all was well.

If this is a LT-1 take the cooler off and remove the adaptor that the filter screws onto.Throw the cooler away.Put the adaptor in the block,like a early model and run a BIG(long) early model spin on oil filter.You will not have any problems with 80PSI.done it on brand X and LT-1 and no problem's.

The cooler has been gone almost since I got the car...I just cant decide whether to still run the bypass or not. Hard to decide when im still getting mixed reviews. I guess a lot of it depends on the filter I run, if I run a good filter with good flow I shouldnt have a problem, but it sounds like even the biggest amsoil filter isnt going to flow well enough to be safe without the bypass.

Sounds like K&N is the right filter? Obvioulsy the biggest one I can fit, but they flow good and filter well enough to not have the bypass as long as the oil condition and pressure is monitored very closely?

Since someone had raised the concept of filtering out 0.1 micron particles....... has anyone determined the practical level of filtration required to protect the various types of engines and uses? If you look at the Moroso website, they make this statement:
Any of the tech oriented engine builders have any thoughts on this statement?

Hyd. oil comes out of the barrel at 55 micron.So you can take it from there.A Fram filter like the NASCAR boys runs will do anything that needs to be done.10 micron on any filter is REAL small.We use them on our hyd pump's and if new oil is not pre filtered,the filters (10 micron) have to be change every 4 hours running time for three or four days.

the wix has its own internal bypass correct?

But you didn't check to see if the rods hit the pan before you yanked it off the engine stand? hmmmm

Unless the motor is never going to be started up cold it's a good idea not to plug the thing. It's in JPE's book on engine building and yeah I agree that you should change your oil but any odd situation where the engine starves because of lack of oil is going to cost money. Coated bearings, synthetic oil are only going to last so long before the motor is junk. I've ran a motor on a dyno with Mobil 1 and no oil pressure on one pull. Polish the crank, new bearings and you are ok, and that was half of one pull! Most times a motor goes because the guy is not concentrating on the oil pressure gauge like I was. Dyno numbers pop up when you are done, the computer controlls the RPM so all you gotta do is make sure it's still healthy.

Most of the synthetic oil you run anyways is dirty, it's job is to pick up and trap the crap in the motor and take it too the pan and up thru the filter, but the stuff that doesn't get filtered stays in the oil. Then the bearings need to have embedabilty for the big parts. Good bearings can take up particles MUCH larger than the filter ever will be able too.

I know it must sound like a crime to you guys but I run 5w-30 Mobil 1 in my daily driver for 5000miles a pop. Now if I built the thing it's going to be in there half as long. The standard 3,000 miles is something that's been around forever in the US and we just go along with it. The standard interval for most companies around the world is 5-10K so 5K is on the low end.

On that note even when being paid contingency money I only run Mobil if they pay or don't. I also use either the AC Delco Filter, K&N or Mobil 1 filter only. I usually pick up the Mobil 1 because nobody around here seems to carry the AC Delco one. There is a long Truck style filter that the LS1 boys like to use but I have a problem with my filter being one of the lowest things on the car. I had a old VW with a cast pan that was the lowest thing and in the 40K miles I owned it the dam thing got busted 2 times! One we due to a rock in the road and the other a Joey Chitwood jump, but either way it should hit the cross member not the oil pan first. Nothing fun about cleaning asphalt out of a motor when you are hanging under the car. If you can move the filter then by all means get as much filter as you can get in there then!

Another point of this whole thread is oil pressure. It's partially due to bearing clearances but also to the oil. 35-40psi at idle is great on a street car but no need for it to be at 80psi ever. 60psi is about as high as you need it to be in about any condition in a SBC motor.

Bret