Plugging oil filter adaptor bypass...any cons?
 

Im in the process of plugging the stock adapter bypass up right now. Either weld it shut, or thread a stainless bolt in there...are there any cons to doing this, or a better way TO do it...besides buying one for $40+?

If this doesnt belong here feel free to move me.

usually use a 1/4 NPT plug

but most people don't realize that the Oil Filter adapter bypass is really a "Pressure Differential Valve" ...that responds to a small 5 to 8 psi pressure differential

if Filter begins to clog up or if any reason oil flow thru filter is reduced ..then if a pressure differential on either side of bypass valve exceeds design psi..valve opens bypassing most of oil

but if that doesn't happen...bypass doesn't open because oil pressure is same on both sides of valve
and 100 percent filtration
or so its designed to ?? :)

i've run the ByPass either way..but if you plug it for 100. 0 % PerCent filtration..then you better choose a hi-quality oil filter that can handle that volume flow without collapsing or distorting filter element...because if it does..your bearings will be starving for oil with failure looming .

I actualy see presure drop on my gauge. Had coolant leak into oil and it pluged filter my pressure went from 60 at idle cold to a max of 30 no matter what the rpm. I seem to have to run the either the high flow from fram (HP series) or gm or I see less pressure on the gauge.

John Carpico

I plan on running the Amsoil filter that is about 2" deeper than the one designed for the car. Takes almost a whole quart to fill up, and is about $12, so Im not too worried about that, plus I still change the oil around 3000 even though they say 8000 or more.

I just dont like the idea of unfiltered oil going back through the engine, and Im sure it could happen even if the filter isnt full, so it could happen under normal conditions.

I should probably use a brass NPT plug im assuming?

Possibly no oil, vs dirty oil. I'll take dirty.

Very true, but an engine well maintained wont ever have to deal with that situation :)

I'm with Serene. Dirty oil over not enough oil any day of the week.

And not just becuase the filter is plugged, either. Just having COLD oil could cause the filter media to become a restriction.

As a down-and-dirty test.... put a quart of standard 10W30 in your freezer (if your wife/girlfriend will let you). Leave it in overnight. Take it out, pop the cap and try to pour it. Guess what you got? Something that resembles half-melted candle wax as much as it does motor oil. Imagine trying to shove that through the microscopic pores of an oil filter.

In the sixties chevy accually had a canister filter that from what i've been told filtered 100% or very close to it. they went away with it because it was "messy" when changing the oil. i actually threw one away when i was 16 because i didn't know any better. the canister filter doesn't have a bypass and the canister is made of metal not "tin" like the regular spin on filters.
In my own opinion if you plug the bypass use synthetic, you'll have a less chance of exploding the filter when the engine is cold.

Having recently dismantled a very expensive LT1 Stock Eliminator motor that failed due to an internally collapsed, name brand oil filter, I'd be VERY reluctant to block a by-pass on ANY application ever again. The non-synthetic oil in this engine had fewer than ten runs and was clean. Forty degree temperature and a filter that did not incorporate an internal by-pass combined to destroy the bottom end. A new set of Crower rods, a steel crank, a full set of King bearings, and an expensive set of top rings are in the trash can. Having a "trick" like a blocked by-pass cost this unsuspecting individual several thousand dollars.

Good luck

These replies are making me wonder why people do it in the first place? On the brand new motor I will be running 5-30 synthetic, and it wont be running in anything below 40* weather so I dont really see the problem. Anyways, the bypass hole isnt much of a "low restriction" hole at all, meaning I think cold oil would have almost as hard a time going through it as the filter. Ill take thousands of small holes over a 1/4" diameter hole that doesnt even open to straight through flow anyway.

Need some opinions though from people that do this and why. I tried the 1/4" npt plug and dont understand how that works cuz it just threads all the way through and doesnt stop. so I made a plug out of alum. and am going to TIG it shut.

But if I get enough negative opinions from preferable engine biulders not "I heard" people...Ill scrap the idea.

A ~1/4" hole is very low restriction when you consider that the diameter of the oil passages inside the block are not really much bigger than that.

I'll just throw out that if the filter isn't a restriction the bypass will never open anyway. If it is, it will. I'll take Max Race's estimate that the bypass opens at a differential of about 5-8 PSI across the filter media as roughtly right (I have not attemped to measure it's opening point but that seems about right to me). It's a safety valve. If you want to run without it, that's fine. Many people have without problems. I'd just ask myself what is the potential downside of running the bearings starved for oil vs. the potential downside of running some partially-unfiltered oil through the engine some of the time?

What about concerns with running higher pressure than stock? I plan on using a white(80psi) spring in a stock blueprinted pump. Maxrace says that its a pressure differential...but wouldnt that change when there is higher pressure, that bypass spring just seems way too easy to push down that oil wouldnt go through it even when not supposed to when the pump is pushing that much pressure?

Im not necessarily arguing, just trying to get as many angles as I can on this, I really have nothing against running a bypass adapter (except that I already made it into a non bypass), can always buy a new one..just heard from someone local to remove it

I plugged the bypass on my new 385 and am glad I did. After initial start up I had a couple rods hitting the pan and had to pull the pan off to clearance. I tore apart my oil filter to check for metal and found some in the filter from where the rod was hitting the pan, without the bypass being plugged who knows if any metal would have ended up in my bearings. I have since put 2000 miles on the motor with no problems. The factory puts the bypass in for idiots who never change there oil. I use a Baldwin B6 oil filter and have not had any oil pressure problems running Mobil 1 10-30

As long as you have a real preasure gauge you see the pressure drop as the filter becomes dirty. What I thought was coolant plugging my filter was actually 10w40 kendal crushing guts of a cheapy fram I used just to get all crud after cam change, it was about 35 degress though.

Ran with bypass plugged all summer same oil no problems. Its a real eye opener when you see how easily the pleats fold over in a oil filter.

John Carpico

Thats what I like to hear, opinions from people doing it. I have a "REAL" pressure gage so will just make note what it runs at on new oil/filter and will note any drops in pressure as getting close to a change.