Correct way to blocking the oil filter bypass ?

[JDEstill]

If there's a way to increase the spring rate in the plunger, I'd sure like to know it. Tell us what you find Jim!

I've got mine blocked, and I'm satisfied I made the right call for me. If I get worried about it I think back to my cam break-in. If 2500-3000 rpm immediately on a cold engine didn't collapse my oil filter, I don't think everyday driving will either.

Absolute pressure doesn't collapse a filter, it's pressure drop across the filter that does it. Oil flow, oil viscosity, and filter size are the players there. With my stock size pump, 10W-30 oil, and PT&E turbosaver, I haven't had any such problems yet.

Admittedly, I would feel better if I could have raised the bypass opening point from 5-10 psi differential to 20 or 30. If I could have done that I wouldn't have plugged the bypass.

John

 

[tom h]

Originally posted by 1of1547
Leave the plug ALONE. I did the mine the way the Power Manual explained it. First it collapsed the oil filter. Then it ended up blowing the drivers side lifter feed plug out. So that wiped out 6 new lifters. Then the plug went through the new timing chain...

Are you sure the lifter oil gallery plug blowing out was directly caused by blocking the bypass??

Blocking the bypass forces all the oil to flow thru the filter... since "filter only" is MORE restrictive than "filter + bypass open", there should actually be a bit MORE pressure DROP across the filter, or LESS absolute pressure downstream of the filter.

 

[tom h]

A pic to clarify what I've been doing on the oil pump cover/ filter adapter:
http://community.webshots.com/photo/63093078/63093404ZqHtkM

However ... I wish I had left the darn thing alone, 'cause I am getting weary of all the time I've wasted on it!

Since the pic was taken, I have tapped the bypass's empty hole 1/2" NPT. The problem is that there is not enough depth to run thru the tapered NPT tap enough, to make the tapped hole large enough diameter, to get more than a few threads engagement on the pipe plug ... so the pipe plug sticks out WAY too far ... interferes with the oil cooler adapter that fits over the pump cover.

Wasted a lot of time searching 'Net & NAPA store for a shallow pipe plug ... no luck.

Will probably either:
- re-tap the hole 1/2" straight pipe thread (allows more thread engagement), or
- have a machinist modify a pipe plug, or
- reconsider a tap-in Dorman plug

I did consider the shallow 1/2 NPT plugs used to seal electrical junction boxes, but turns out they are made of thin, flimsy cast zinc or something ... an engine disaster if it were to crack into small pieces.

People at work think I'm nuts, lavishing so much effort on an oil pump ... If it's not one thing, it's another !

 

[FJM568]

Here's a thought...Hit the salvage yards and find another pump cover off of another 3.8L...Then either resurface the thrust surface or use a booster plate and drive on...

 

[tom h]

Originally posted by tom h
... I have tapped the bypass's empty hole 1/2" NPT. The problem is that there is not enough depth to run thru the tapered NPT tap enough, to make the tapped hole large enough diameter, to get more than a few threads engagement on the pipe plug ... so the pipe plug sticks out WAY too far ... interferes with the oil cooler adapter that fits over the pump cover...

Browsing thru my McMaster-Carr industrial catalog, I now realize the type of pipe tap needed was a:

Taper Pipe Taps for Shallow Holes ... Also known as short projection taps, these pipe taps are used where tapping depth is limited ... allows full threads close to the bottom of the hole.

Irks me to spend another $34 on a special tap, after I had already bought a $12 Home Depot tap. Live & learn. After all this, I should set up a small business to plug Buick oil bypasses! Whee -- retire early

 

[tom h]

Originally posted by FJM568
Here's a thought...Hit the salvage yards and find another pump cover off of another 3.8L...Then either resurface the thrust surface or use a booster plate and drive on...

As it turns out, I still have my original, low mileage filter adapter. All this screwing around has been on a new, spare adapter I bought years ago.

Putting the original adapter back would be too easy ... it's now become of battle of wills between me & the Buick!

 

[FJM568]

I am doing a little checking around...Trying to see about maybe doing something with the bypass spring and maybe figuring out how to do an easy mod to upgrade to a stiffer bypass or something...Need to make a few phone calls and check about some parts and what not, but I will try to keep this topic running...I'll post back with my findings...Maybe trying some mods with the oil pump cover...Just some ideas...I need to look into a few things though...

 

[Quick6'n'-K.C.]

a dime fits perfectly

just jb weld it into place

 

[tom h]

Victory is at last mine! (accursed oil bypass!)

I did some research on the web and in Machinery's Handbook, and found there's 3 or 4 official variations of "NPT pipe thread".

I got hold of a 1/2" NPSF Dryseal American Standard Straight Pipe Thread tap.

After re-tapping the vacant hole in the oil filter adapter with the straight tap, and using a tapered 1/2 NPT pipe plug, I could now insert the plug several threads deeper -- but still not flush.

What I SHOULD have used is a NPS American Standard Straight Pipe Thread tap, which makes a slightly larger diameter straight threaded hole.

So what I did next is hack-sawed a few threads off the hex-socket end of an aluminum NPT pipe plug. This still left adequate engagement of the hex key into the socket.

So now the pipe plug is nearly flush with the vacant hole where the bypass used to be. No interferences, and no restriction of the oil flow to the filter. There are still 3-4 threads of the plug engaged, which should be plenty. A bit of blue loctite, and that plug isn't going to budge.

Tomorrow, deflash or smooth down any remaing burrs on the filter adapter, clean thoroughly, and re-assemble.

After all the effort expended on this filter adapter, I should gold-plate it and use it as a decorative knick-knack on my coffee table ...

What would I do differently next time? Maybe leave it alone ! At least, no more worries about ever getting shrapnel thru the bypass and past the filter (in theory).

 

[REDS HOT AIR]

now after you starve your motor for oil when the oils cold you can replace all the bearings and put a by pass housing back on

 

[lazaris]

now after you starve your motor for oil when the oils cold you can replace all the bearings and put a by pass housing back on

Right just like Jim Ruggles always did....................

 

[tom h]

Originally posted by REDS HOT AIR
now after you starve your motor for oil when the oils cold you can replace all the bearings and put a by pass housing back on

Reds, I'm not quite that pessimistic. I know it's happened to unfortunate users, but near the beginning of the post I did also comment that:

- using a Baldwin B9 filter ("super Biggie", 25% larger than PF24), and more rugged construction than Purolator or Delco

- using Mobil1 5W-30 oil.

- My climate is mild (winter temps rarely below 50ºF).

- I'm the only driver, mashing the pedal when cold won't happen.

Most of the threads I read of collapsed filters, seemed to involve mainly thick oils, or hi-volume pumps, or maybe undersized filters.

I've also read more than a few threads where something inside the engine broke, created shrapnel, and then passed thru the bypass and trashed the engine. This is what I wanted to protect against.

In fact, I once had a 1984 V6 Buick Regal 4dr sedan (non-turbo, daily driver), where EXACTLY this happened. Ended up having the dealer install a remanufactured engine (2 weeks and $2500 later...).

If I get any qualms or second thoughts, I also have a good plan "B" : Baldwin makes filters that are similar size & shape to the super-large B9, except they have a Built-In 20 psi bypass. This is far less likely to open than the stock 8-9 psi bypass in the filter adapter, yet Would provide lube if the filter were to collapse.

 

[REDS HOT AIR]

cool

stock size filter with regular oil aint gonna cut it but sounds like you planned ahead.

 

[tom h]

Here are pics of the final, finished oil filter adapter with the plugged filter bypass:

http://community.webshots.com/album/63093078uJqZEQ

I installed the modified adapter on the '87 GN today... finally!

Tom 1, oil pump 0

 

[Quick6'n'-K.C.]

Originally posted by Quick6'n'-K.C.
a dime fits perfectly

just jb weld it into place

 

[tom h]

Originally posted by Quick6'n'-K.C.
a dime fits perfectly just jb weld it into place

What I should have said, is
Tom 1, oil pump 0 after 3 weeks and wee bit more money than I had planned on!

Have you checked to see if the dime is still there ?

 

[Quick6'n'-K.C.]

im lazy and make it simple....

yes it is still there

 

[tom h]

Originally posted by ILBCNU6
I just posted my opinion on blocking of the by-pass valves on the oil pump booster plate posting. I wouldn't ever do this! ... Your choice to do or not to do. Good Luck! Gene

Yes, it's controversial and should not be done unless one is fully informed of the pro's & con's.

I once had a Buick V6 (non-TR, non-racing) engine trash itself from shrapnel that got all thru the oiling system, bearings, etc. I wanted to reduce the the risk of that happening on "my preciousss", hence after much deliberation decided to plug the filter bypass.

Up above I outlined the steps I took to prevent a collapsed filter & loss of oil.

 

[JDEstill]

Originally posted by ILBCNU6
Not only my opinion but another "Buick" oiling expert agrees with me.

Gene, there are certainly strong feelings on both sides of the issue. I'm sure some experts agree with you, but other experts also say that blocking the bypass is both acceptable and desirable. I agree with Tom, anyone thinking about doing it should research it carefully and decide whether or not the pros outweigh the cons for their particular situation. I think they do in my case.

John

 

[tom h]

Originally posted by JDEstill
With my stock size pump, 10W-30 oil, and PT&E turbosaver, I haven't had any such problems yet.

Admittedly, I would feel better if I could have raised the bypass opening point from 5-10 psi differential to 20 or 30. If I could have done that I wouldn't have plugged the bypass. John

John, if you're using a PTE turbosaver I believe the typical remote filter used with those is a Baldwin B279 racing filter ... those filters have a built-in 20 psi bypass. 20 psi seems a good overall compromise. You have the benefit of having plugged the wimpy stock bypass, yet still have the protection against a catasrophic filter collapse.

If I ever get nervous about my blocked stock filter bypass, I think Baldwin makes variants of the super-large B9 filter I'm currently using, that have a 20 psi bypass in them.