Oil filter bypass valve

[MaineShark]

What pressure differential is necessary to trigger the oil filter bypass valve? I don't want the added pressure drop of my oil cooler to trigger the bypass.

I know that some big-blocks require a different valve for that reason, if an external cooler is added, but I'm not sure what pressure the small-block bypass valve activates at.

Joe

 

[SwaveDave]

Its a fairly common practice, especially for racers who have very expensive motors, to plug the oil filter bypass so ALL the oil goes thru the oil filter ALL the time. I did this recently on my own vette which is for street use only. There are some safeguards you have to take however : Use a good flowing oil like 5w30 , use a strong oil filter like K and N's Performance Series Filters with a higher pressure rating and a good seal, and just in case the oil filter does become restricted (albiet very very unlikely if you change them every 3000 miles)...its a good idea to have a low oil pressure switch that will stop the engine . I do all of the above on mine. Has worked well for the last few months with no problems whatsoever. If you dont want to plug the bypass , you can even replace the oil filter Mount with a new one from Jegs which is for FULL flow thru the filter ($39).

 

[MaineShark]

Thanks. Right now, I'd like to keep the valve - I'd just like to make sure that it won't trigger unless there is an actual problem.

Joe

 

[SwaveDave]

I recall reading in a Racer Mag about 4 months ago, that GM's oil filter bypass starts bypassing around 8 psi differential. Dave

 

[Vader]

Maine,

Good call. Keep the bypass active. I've seen a couple of the older SCB eaten up from oil starvation after the bypass was plugged. Factory specs give a range of 7-10 PSIG differential depending on what reference you're reading.

Mewer SBCs don't seem to suffer from this malady since the bypass was moved to the bolt-on filter adapter. Either way, dirty oil is better than no oil. If you do your maintenance, the bypass will seldom open anyway. Cold, thick oil and higher RPMs happen on occasion, so the bypass can be a nice feature.

 

[MaineShark]

If you do your maintenance, the bypass will seldom open anyway. Cold, thick oil and higher RPMs happen on occasion, so the bypass can be a nice feature.

My issue is the installation of the oil cooler. I'm not sure how much of an additional pressure differential this will create. I want to make sure I don't end up running bypass, all the time.

Is there any good test to determine if the oil is flowing properly? In order for there to be a pressure drop, some oil will have to flow up into the cooler, so I'm not sure if I'll be able to determine by feeling the cooler, whether it's getting full flow, or only partial flow.

Joe

 

[SwaveDave]

Maine,

This will give you an idea : I had two 11x8x1.5" thick B&M Oil filters piped in series on my BB's radiator ; after i removed them both, the console oil pressure guage read exactly 10 psi higher.

Dave

 

[MaineShark]

Back to the top, to see if anyone knows of higher-pressure bypass valves that can be installed instead of the OEM valve...

I like the insurance of having the valve, but I'm worried about the factory valve kicking out (or even opening partially), with the pressure drop from the cooler.

Joe

 

[SwaveDave]

You could call GM and ask them if they offer a higher bypass valve than what your corvettes is ;maybe they used higher rated valves on other GM cars .

I think you should do away with having a bypass valve altogether , and still have the assurance youre looking for by taking the proper precautions i mentioned above. Racers with very expensive engines have been eliminating the bypass valve for many years now in order to have 100% oil filtration and prolong the life of thier motor ; do u think they would do it if they were taking a chance on ruining thier motor ?? ...and they run thier motors alot harder than we do. Im going to eliminate the bypass valve on every future car i own from now on ; but ill be safeguarding myself by using a good Heavy Duty high flow oil filter like KandN's performance filter, using 0w30 synthetic which flows well upon startup, and a low oil pressure switch to kill the motor in case the oil pressure should occur for any reason.

Eliminating the oil filter bypass would give you the benefit of cleaner oil/engine parts, and also take care of your other concern. For a while, i was running TWO oil coolers in series with the Oil Filter Bypassed...and i had no problems whatsoever. My oil pressure was 70 psi at 2000 rpms and higher, and 40 psi at idle.

Dave

 

[MaineShark]

Racers with very expensive engines have been eliminating the bypass valve for many years now in order to have 100% oil filtration and prolong the life of thier motor ; do u think they would do it if they were taking a chance on ruining thier motor ?? ...and they run thier motors alot harder than we do.

Well, I do think part of that is maintenance cycles - I'm sure they change their oil and filter after each race, so the chance of a problem is less. I'm not really prepared to change my filter quite that often...

But I may plug the bypass, if I can't find a replacement bypass that will work better.

If I do, maybe I'll replace my single remote filter mount with a dual-filter mount. Two filters would make the chance of a clog, all but zero...

Joe

 

[SwaveDave]

When i said 'racers' , im not talking NASCAR only...but drag racers also. I doubt they change thier oil and filter after a few runs ; instead, they employ safety devices to protect the motor.

Your idea of a dual mount oil filter is a good one for added security and better filtering yet.