I ran across this itm in the SPDC catalog...

http://www.sdparts.com

Fromw the website..."Plug the oil filter by-pass in your stock oil filter adapter to allow all oil to flow through the filter. The stock valve bypasses at only 4psi allowing most of the oil in your system to bypass the filter. Convert your system to full time filtration by using the easy to install plug."

Would this be a bad thing, to filter your oil 100%? To me, it seems like a good thing. Just have to be SURE, your filter doesn't get plugged, starving the engine of oil, I guess.

Opinions? Thoughts? Experiences?

 

Hi,
I can't give my experience yet (need to finish the job) but I have opt for an equivalent option.
http://store.summitracing.com/partde...5&autoview=sku

I don't see any problem by filtering all the oil that goes to the engine, it should be better in my opinion.
But like you say, you need to watch the filter, frequent changes of it, will give a guaranty and as soon you see any oil pressure drop you will need to act and put a new filter.

Regards,
Cobra289

 

Nothing like selling the people something that does nothing.
The stock bypass will stay closed at all times anyway unless a very unusual circumstance happens. The bypass limits the pressure differential on the filter media to prevent if from rupturing if it becomes plugged. Since the oil is being pumped continuously thru the filter, the oil in the crankcase becomes "filtered" oil in a short time. It's better to send this oil to the engine parts than none. If the filter element ruptures it will spew whatever it has trapped straight to the bearings.
If the element is so plugged with metal that the bypass opens, the engine's days are numbered anyway.
The other unusual condition that the bypass would open is like this:
The engine is at 0°F, dumbass has 15W40 oil in it and revs the cold engine to 3 grand. The bypass would open because the thick oil won't go thru the media quick enough to stay below the rupture pressure of the media.
Remember, GM spent money on each engine to put this in. If it wasn't needed, trust me, it wouldn't be there.
If you're worried about the bypass opening, get the "long" version of the oil filter instead, like: AC PF1218 $3.49 @ AZ (different year engines, different number) Your engine will have more oil capacity and the oil will run a little cooler. If you don't have LT headers it will screw right on.

 

I do this on all high performance engines I build. You can pop the disk and spring out yourself and tap the adaptor for a pipe plug. Real easy. The first time you get some trash in a motor (bad bearing, cam lobe, etc.) you will thank yourself profusely.

RBob.

 

Right...

One of those "old wive's tales" type of things that just won't go away. Maybe was applicable back when oil filters were alot more crude than they are now, but no longer have a place in a street motor. Unless of course, you're willing to let the engine warm up FULLY, i.e. idle for about 10 minutes or so, EVERY TIME you drive the car; and you will NEVER EVER EVER start it when it's cold out, like below freezing or so, because you WILL blow the oil filter off the side of the motor.

There is no benefit to it whatsoever on a street motor. On a RACE-ONLY motor, where the engine ONLY sees ONE set of operating conditions (hot summer afternoons, WOT, 30 seconds at a time, total engine life 3-4 hours of operation between complete rebuilds) it might be useful; but this is a perfect example of how things that might be OK good on a RACE car, are BAD on a STREET car.

And apart from the issue of whether it's appropriate or not, which this typically falls into the category of "if you have to ask you don't have any use for it", you can take a stock bypass valve body, munge the valve out of it, and put a ¼" pipe plug in it that you can buy at the hardware store for a couple of pennies.

 

Hi,

Now I am lost!
I thought that every filter casing has at least a rupture pressure of 300 PSI.
So how much will be the shut-off pressure of an oil pump that has also an internal relief valve st to 75 PSI ?

Also considerable amount of filters will have a relief valve set to 10 or more PSI.
I am wrong to say that when the filter is clogged the filter relief valve will go open?
In the event that this one will get closed the relief valve of the pump will force to circulate and get hot too?

So why having two by-pass on a street car?

I will learn guys! and never it to late to do it!

Regards,
Cobra289

 

You've obviously never seen one get blown off then!!! Believe it, it happens. And not just super cheeep made in China ones or whatever; a dent in the side of the casing can weaken it enough to cause trouble.Well, think of this: you know how that valve works, right? it's a little thing like a plug, that's held in place with a spring, that moves to uncover a passage when the pressure on it exceeds whatever the spring tension is. Read that again: it uncovers a passage.... How big is that passage? How much pressure can still exist if the oil can't flow through it fast enough to bleed off enough pressure? You might be surprised at how much pressure a pump can develop ABOVE its alleged regulated value, especially when used with thick oil like hot-rodders think for some reason they need to use.

You're right, when the filter is clogged, the relief valve opens. On a Chevy motor that happens at about 4-5 psi of pressure drop across the filter. Not all filters have a bypass valve. The pressure drop across the filter can occur for a number of reasons, the 2 most common being, dirty filter, and too thick oil. Yerbasic hot-rodder seems to think that because "real" race cars use thick oil, then "they" should use thick oil too; without thinking about WHY race cars use thick oil which includes things like getting diluted by excess fuel (alcohol cars especially). Which DOESN'T APPLY to a street car.

As was said, having NO oil (or too little oil, because the filter isn't flowing oil)get to the bearings, is much worse than having DIRTY oil get to the bearings. Read again: NO oil is worse than DIRTY oil. Therefore, PLUGGED bypass is worse than WORKING bypass.

The correct answer is to use normal weight oil (10W-30 or similar), NOT straight 50 or something; and of course, keep a clean filter installed; and leave the bypass alone and let it do its job in the unlikely event that it's necessary.

 

 

You did recall me some good memories. I remember once 40 years ago with my dad the filter went off, what a mess, but we found that it was due to that the thread was burst at the nipple. It was a "Renault Gordini" nice time.
And yes and small change of the rounded shape can destroy the integrity and reduce the strength.

I use to fill the engine with full synthetic 5W40 from Kendall and I can tell you that after two seasons and have drive for 5000 miles the oil still has the gold color.
Part of that, is because I use to drive (highway runs) with LPG and only at the Road Course and some club shows, use the petrol.

My filter never last more than two years and the above mentioned miles, I don't have engine oil cooler so just as a precaution I change the oil before it gets de-gradated, and a filter is so cheap that goes in with the oil change.

I wish I could buy here the "Mobil M1-301" I have heard good references, till then I still use the AC Delco blue ones.
Thanks for the info!
Regards,
Cobra289

 

The implication in the ad, was that at 4 psi, the bypass opens, regardless.

So, say your running at 25psi normally, that would mean that some of the oil is NOT getting filtered, because of the bypass.

 

Follow these instructions to the letter.
Also

 

No, that's at 4 PSI of pressure drop across the filter. If you had 25 PSI of pressure after the filter, you'd need 29 PSI before the filter for the bypass to open. That won't happen under normal conditions.

 

You mean a 4psi INCREASE then?

The way it reads..."The stock valve bypasses at only 4psi..." It says it opens at 4 psi, not 4psi, over stock, or regular pressure. How would it know what it "normal" anyways?

At start up, I'm pushing like 45psi, that drops to 20-25, as the oil warms up.

 

4psi of resistance through the filter, not 4psi of oil pressure

 

So your saying, it only opens at 4psi of resistance?

Otherwise, the filter is filtering 100%, UNLESS it gets resistance?

 

Lets try to put this clear (If I can)

The oil that comes from the pump can run in two directions.
(A) Via the filter
(B) Via the valve that according to the ad it opens at 4 psi (stock oil filter adapter)

The pump will push and the oil will take the route with the less resistance, in this case the (A) route.
When the filter get dirt and need to have a push of 4 psi the oil will choose the other path the (B) route, via the valve.

At this point the full pressure is not build up yet, it is at the bearings when the pressure of you system get build up.

So if your gauge say 45 when is cold and 20-25 when is hot, it has nothing to do with this above mentioned by-pass.
20-25 psi has to do with the clearances at you bearings.

NEXT Pressure
The oil pump has an other pressure relief (you know the classic spring) this take care that the pump will recirculate internally the oil when the pressure in your system is to high, like thick oil in combination of cold weather or to thigh clearances.

NEXT Pressure
Several filters (good ones) have their own protection and they have also a pressure relief devise inside the filter.
When the filter get dirt and pass the specified pressure by the filter manufacturer the relief will pop open and will flow with out passing the filter element.

So looking to this complex pressure devises and the redundancy of some of them, I have choose to have the oil filter with a Relief Valve and forget the STOCK oil filter adapter bay-pass.

It is nice to have double redundancy but I like to keep the things simple, don't need to be dummy proof!

Regards,
Cobra289

 

If you are the type of driver that beats on a cold engine, or that when it is -20 out doesn't allow the engine to warm up a little, or they dent and mash the oil filter installing it, or run straight 50,000 W oil, then don't block the bypass.

However, if you are smart and take it easy on a cold engine, and let it warm up a little in -20 degree weather, install the oil filter properly, and use a decent filter (such as Wix) then no harm will come with a blocked bypass.

Note that my original post said high performance engine, not your run--of-the-mill daily driver.

And with a hi-po engine one should be keeping an eye on the oil pressure, with a real gauge. So if the filter does start to become clogged you notice the drop in pressure. And you can do something about why it is clogging.

Which is much better then having your engine destroyed because the filter is clogged and the bypass opens allowing the trash to circulate through the engine. Because with an active bypass you won't know that the filter is clogged since you still have oil pressure.

Blocking the bpass is inexpensive insurance on high performance engines.


For those asking about how the bypass functions: it opens when the pressure differential between the inlet of the oil filter and the outlet of the oil filter exceeds 4 psi. IOW, the pressure drop across the filter itself.

RBob.

 

I'll with that.
Most "true" high-performance engines don't get run below 32°F at all...

 

True enough; that being the thrust of my comment about "RACE-ONLY" setups....

But lots of street cars do.

And as far as "looking at the gauge", how many posts have we seen here where the wife/GF/friend/cousin/co-worker/whatever drove the car that had the fanswitch/tempgauge/OPgauge/TCCswitch/whatever, and didn't know how to work it? Only takes making that mistake ONCE, and the car is now GARBAGE. Not a risk to be taken lightly.

I'll stick with the stock arrangement in this particular case for a street-driven motor, thank you very much. The guys at the factory aren't "dumb", they just .. have reasons for what they do that we might not catch onto at first. Rule #0 of modding is, "understand what's already there and what it does and WHY, before ****ing with it".

 

Now THAT should be your signature. That's solid advice there. Too many people rip out "smog" accessories then ask why (insert strange problem here) occurs. Such as a high RPM oil leak for example. etc etc.

 

It sounds like something like this wouldn't be a bad thing.

If it comes on at 20psi, it sounds like my car, would be very close to lighting it up.

 

Then don't use a dented filter I worked at a higher end lube shop (not some cheap ghetto place like Jiffy Lube) for a couple years and we were forbidden to put on dented filters. On filters that were used we would punch a hole in the side to drain the oil. Some were paper thin and you merely had to tap it with a pry bar to make a full-sized hole, and some you had to sit there and go to down on to just start a hole. All OEM filters were very thick and I can tell you would never rupture no matter if it saw some insane 20-50 diesel in sub-zero weather, even with a dent. It's unrelated, but my 1g DSM factory service manual says that the OEM filters are specifically designed to deal with pressures up to 256 PSI because of high oil pressures in very cold weather. Bypass, or not, use a cheap filter in cold weather at your own risk.