Changing the oil filter bypass pressure

[Sleeper-6]

While I was spending the time to port all of the oil passages in my front cover, I got to thinking about the filter bypass valve. So I ground off the stakes holding the plunger in the filter adapter and took it apart. I measured it up the spring and got the following.
Wire diameter = .034"
Spring diameter = .483"
Active coils = 6
I used this to calculate the spring constant of 7.4123

I went on measuring the free and installed height of the spring and calculated the spring pressure with the valve seated
Free height = 1.115"
Installed height = .805"

Calculated seat pressure = 2.2978 lbs.

The bypass port is .385" in diameter giving it an area of .116 square inches

2.2978 lbs divided by .116 square inches gave me a 19.8 psi

I believe I read somewhere the the factory bypass valve opens at 20 psi so that showed me the my math is accurate enough.

Now what all this is leading up to is a way to change the pressure that the bypass valve begins to open. I have decided that I do not want to block off the bypass because of the possible issues with blowing apart oil filters. I would however like to raise the pressure that the bypass opens. I'm thinking that I will target around 70 psi as that will be the max I suspect the engine see under normal conditions. That will give me filtered oil at all times but still allow excess pressure to bleed off during cold starts. With the above calcs I should be able to accurately determine the spring I need to do this.

Has anyone done this before or have any other input as to what pressure I should target as the bypass cracking pressure?

 

[turbofabricator]

Block the bypass with a pipe plug, and use a dual remote filter, or a HP6 Fram. The HP6 Fram is HUGE!!! The factory engineered the bypass, because of the teeny-tiny filter they use. As soon as the engine starts, the by-pass opens immediately. Very little oil even gets filtered in our cars. The bigger the filter, the better. BUT........even in completely stock form, the oiling system, with all it inadaquacies, still works FINE in even a 500 HP engine. Still scares me though.

 

[bmackinnon]

Where did you get numbers to 'calculate' the spring constant? Material properties of spring steel? How do you know the spring mat'l? I think "I" would want to verify my calculations with measured pressure data at the bypass before I assumed all was good after a configuration change.... which is probably not feasible to do...... at a minimum, measure the actual spring constant (lbs/in.).... that's easy enough....

 

[Sleeper-6]

I used the calcs on engineersedge.com. I used 30,000,000 as a generic modulus of elasticity. Using my "calibrated thumb " the numbers seem about right. I will have to bring them into work and check with the force gauges to verify.

If someone can confirm that the factory spring opens the valve at 20 psi I will consider my 19.8 calculated pressure accurate enough for what I want to do.

As Ken said, very little oil is filtered using the factory configuration. I am trying to increase the amount of oil that gets filterd without going to a blocked off bypass/external filter setup. I am using the RJC biggie adapter to get as much filter area as possible in the factory location.

 

[bison]

Mine bypasses at 70 psi and i run a blue spring with the stock length gears. Ive never ran an HV on any of my street driven stock blocks and never had a pressure or bearing problem.

 

[Scott Atk]

I think you might be confusing the pump bypass and filter bypass

 

[Sleeper-6]

Bison, I think you're mixing up the bypass with the pressure relief valve. I plan on using the blue spring in my pressure relief for a max pressure of 70 psi.

 

[bison]

Bison, I think you're mixing up the bypass with the pressure relief valve. I plan on using the blue spring in my pressure relief for a max pressure of 70 psi.

Yes. It wont bypass until it hits the 70psi. I can see it more so when the oil is hot. It gets to 70 psi and hovers there until the rpm gets really high. When its cold it hits 70 psi in about 1 second on start up. The pressure relief cant handle the volume on cold start and high rpm and its byassed into the engine without filtering.

 

[turbofabricator]

Bison.....he is talking about the oil FILTER bypass, not the regualtor spring. He wants to push more oil through the filter. There is a bypass spring in the filter adaptor that is completely separate to the "blue" spring REGULATOR. It is a little plunger you can see with the filter/cooler adaptor off. It is below the threaded spud that the filter/cooler adaptor screws onto. THAT is what he wants to "re-spring" Not the pressure regulator. I just remove the bypass valve (it's knocked in like a freeze plug) thread the hole, and install a pipe plug. You MUST use a filter with a bypass in it, or you WILL blow it apart!!! Been there, done that. I actually had one blow up in my face, once. I maybe a slow learner, but at least I LEARN. Never did THAT again. It blew oil EVERYWHERE!!! In my face, eyes, chest, wall, floor, inner fender, battery, ceiling, wall, wall and more on the ceiling. What a MESS! Thank God it happend on start up, and the oil wasn't HOT. That would have been ALOT worse. I didn't realize a PF-52 doesn't have a bypass valve.

 

[Just a Six??]

Bison.....he is talking about the oil FILTER bypass, not the regualtor spring. He wants to push more oil through the filter. There is a bypass spring in the filter adaptor that is completely separate to the "blue" spring REGULATOR. It is a little plunger you can see with the filter/cooler adaptor off. It is below the threaded spud that the filter/cooler adaptor screws onto. THAT is what he wants to "re-spring" Not the pressure regulator. I just remove the bypass valve (it's knocked in like a freeze plug) thread the hole, and install a pipe plug. You MUST use a filter with a bypass in it, or you WILL blow it apart!!! Been there, done that. I actually had one blow up in my face, once. I maybe a slow learner, but at least I LEARN. Never did THAT again. It blew oil EVERYWHERE!!! In my face, eyes, chest, wall, floor, inner fender, battery, ceiling, wall, wall and more on the ceiling. What a MESS! Thank God it happend on start up, and the oil wasn't HOT. That would have been ALOT worse. I didn't realize a PF-52 doesn't have a bypass valve.

Does the Baldwin B-9 have a bypass built in? I just got a case of them!

 

[turbofabricator]

It doesn't look like the Baldwin B9 has a built-in bypass. The built-in filter bypass is ONLY needed if you have plugged the filter bypass in the oil filter adaptor.

 

[TR Custom Parts]

So what happens with one of the oil filters I sell if you block the bypass? This filter is a full flow filter WITHOUT an internal bypass. Used in many race applications and filters down to 8 microns. Element is in a stainless steel "cage" and is supposedly bulletproof. Been running it for years but not with the bypass plugged.

http://buickgn.com/billetoilfilters.html

 

[charlief1]

You could always run an oberg remote. I have yet to see wne blow up and it uses a cleanable metal mesh filter.

 

[Just a Six??]

So what happens with one of the oil filters I sell if you block the bypass? This filter is a full flow filter WITHOUT an internal bypass. Used in many race applications and filters down to 8 microns. Element is in a stainless steel "cage" and is supposedly bulletproof. Been running it for years but not with the bypass plugged.

Billet Oil Filters

My GUESS is that the one you sell wont blow apart BUT if it ever did I hope to God no one is staring at it! Like a small bomb I would guess? Altho, I dont see it happening? The o-ring would let go first I think?

 

[1of1547]

Block the bypass with a pipe plug, and use a dual remote filter, or a HP6 Fram. The HP6 Fram is HUGE!!! The factory engineered the bypass, because of the teeny-tiny filter they use. As soon as the engine starts, the by-pass opens immediately. Very little oil even gets filtered in our cars. The bigger the filter, the better. BUT........even in completely stock form, the oiling system, with all it inadaquacies, still works FINE in even a 500 HP engine. Still scares me though.

This is one thing that has always confused me. Everybody wants to plug the bypass because it is what the Buick Power Manual says to do so. There's one big problem with the power manual. It is meant for all out racing motors. Not daily drivers and occasional strip warriors. If my understanding is correct, when the motor is started the valve will open to let oil, granted unfiltered, through to lubricate the motor if needed. So if the plug is blocked is the motor more or a less starting dry until the oil is filtered? So wouldn't starting a "dry" motor do more damage in the long run than allowing the unfilter oil on start up? I am not trying to stir the pot here, just trying to figure out how this system works. From my understanding if the car is a driver and it is started in cold weather, especially by somebody that is not a "car" person, leave the plug alone.

I did the oil plug on my first engine. But I only did the oil pump end. At first I didn't tap the lifter valley plug, which was my bad. :redface: After two collapsed AC 24? (455 filter), one the stand and one in the car, it spit one of the Loctited freeze plugs out of the lifter valve and fell into the timing chain. That in turn broke a double roller chain. So if anyone wants a ported plugged housing, go to my old house. It should be down in the woods where I threw it out of frustration. I have since upgraded to a remote oil filter with a System 1.

BTW, if you can find the specs for the stock spring, we spring testers at work that I can check the tension.

 

[Sleeper-6]

I haven't done much more with this recently, but I did however find a replacement from Lee Spring that should give me a cracking pressure of about 62.5 lbs on the bypass valve. I'll have to post the specs and part number when I get home later. I may try to rig up a test plate to put my filter adapter on and confirm the point where the bypass opens.

The measured specs from the stock spring are in my first post. I haven't gotten around to bringing it into work and confirming those numbers with a force gauge yet.

 

[Just a Six??]

Stupid question time?? What happens if you stretch the spring & then install it? Wont that sorta do the same thing?

 

[turbofabricator]

I'm thinkin' just change your oil more frequently and who cares if it is bypassed?

 

[Sleeper-6]

Stupid question time?? What happens if you stretch the spring & then install it? Wont that sorta do the same thing?

It would, For a while at least. I don't know how consistent that stretched spring would be over time. Springs are cheap anyway.


I could change my oil more often, but what fun would that be?

 

[karolko]

sleeper-6, did you get a chance to test your new spring.

I am very interested in doing the same thing to my motor, but i would like to stay away from the plug idea.

Also i would love to get a part number and the place you got it from.

do you happen to have any photos of the spring and how you tested it?

Thanks alot.

Adrian Karolko