ZZ28ZZ

Has anyone deactivated their oil filter by-pass valve?
Any problems other than not being able to rev a cold eng?

ede

never heard of it being done, why would you want to?

RBob

iTrader: (1)

I commonly do it on vehicles where I run synthetic oil that is regularly maintained (filter changes also). I use 10-30W oil and Wix filters.

RBob.

ZZ28ZZ

Lingenfelter mentions the mod in his book "On modifying small-block Chevy engines". It's supposed to be an old circle-track trick.

John reports that when a cold eng is started, the oil bypass opens and allows unfiltered oil to enter the eng.

I checked the spring for the bypass valve, it's not very stiff at all.

I was thinking about doing it to the eng I'm currently building because I'm sure there's going to be some crap inside the eng I failed to clean out.

Maybe after a few oil changes, I could un-mod it. This would mean buying another oil filter adapter, but they can't be too expensive.

PaveTim

I forgot the manufacturer but I bought an oil filter mount with the bypass blocked off. I did not have any problems. I also heard too that if your oil pressure is too high it can possibly bypass the filter all the time. It will not hurt anything. The only thing you have to really worry about is getting a clogged oil filter and blowing it up. But good filters have a burst pressure of like 500 psi so you should be fine.

robertg

iTrader: (2)

i really don't think that an oil seal in the engine would hold up to 500 psi.

don't the seals leak if the pressure is too high?

PaveTim

I didn't mean the oil seals, the oil filter itself. I just meant that the good fram rates theres at 500psi burst pressure. You will not get that much pressure inside the motor.

RICH92RS350

You can either drill and tap the hole in the stock spin-on adapter and screw a plug in it or buy an aftermarket unit that has no bypass (see Jegs or Summit).
Just be sure and let the car warm up a little before you spin the motor over 4500 rpm or the high pressure could cause problems.
-Rich-

ZZ28ZZ

Found it at Jegs $50. Ouch!!

Think I'll just plug mine.

L98GTA

I've been blocking the bypass on my engines for about 10 yrs now. I've never had trouble, but the important thing to remember is to stay out of the throttle until the engine warms up. Otherwise the pressure can rupture even the strongest filter.
If you let other people drive your car unattended that you can't trust to follow instructions I wouldn't do it. There are VERY few people that drive my GTA and those that do know what's going on.

The reason for doing it is that the bypass always allows some oil the circulate past it due to the relatively weak spring. I've heard people smarter than me say between 10 and 40% during normal operation!! Blocking it ensures that ALL oil goes through your filter every pass. This means any little pieces of junk that may find thier way into your engine get trapped in the filter on the first pass through the oiling system not the second or fourth or more.

Even though I do it you can't argue the fact that thousands of small block chevy engines have run with the bypass intact.

Here are some pics of a bypass I blocked of on my last 383. Ran it for 4 years with no problem. I just took a threaded steel plug tapped the bypass hole after removing the plunger and spring then screwed it in. I added some JB weld to make sure it stayed put.

adaptor

Hope this helps

ZZ28ZZ

L98GTA>
I wasn't able to see your pics, but I have a pic already from one of Lingenfelters' books.

No one drives my car except me, and I really baby it when cold.

That spring is really weak. I was shocked when I checked it.
No only that, but while I was playing with it, I got it to stick in the partially open position.

Wonder if a larger (taller) filter would help with the high differential press when cold..

Damon

ZZ- I know what you mean about the weak spring pressure. It's really REALLY weak. Probalby 2-3 PSI and it would open. I don't doubt that it constantly leaks some percentage of the oil past the filter in normal operation. For all I know that was it's intended purpose.

Remember that most stock engines are designed to run 5W30 oil that gets thin as water when heated up. If you run thicker oil I can see where the bypass would open even more.

All that being said, the factory engineers are no dummys. They made it weak for a reason. I won't claim to know all of their logic but I've run the stock filter adapter with the "weak" bypass on all my street engines for almost 2 decades and never had bad results to report.

I DO run the "long" style filter (Fram PH13 vs. the shorter Fram PH30) whenever clearance permits so there's as much filter area for the oil to pass through as possible.

Damon

As a side note- I always change the oil in my engines after only a few minutes of running after initial start up (just as a general rule). Maybe 20-30 minutes. If there is a certain percentage of oil that regularly bypasses the filter then you can imagine the importance of getting rid of the "dirty" break-in oil very soon after initial startup. Get that junk outta the motor- the filter may not be catching all of it.