Engine Oil Filter Bypass inquiry

Tydriver

Tydriver

TurboLS6 Powa'
Just thinking outloud here, I was contemplating this in the car on my way home from work (since i have a 1.5hr commute I have alot of time to think)


Has anyone setup their oiling system to force all the oil through the filter assy instead of allowing the BYPASS setup to function ??

After my oil related failure on my engine (or lack of oil as the case maybe) I got to thinking, had I possibly had the filter doing its job on ALL the oil, it may have NOT gotten as bad as it was/is.

Its my understanding that there is a bypass setup near/in the filter relocation area of the block that allows oil pressure to BYPASS if the pressure gets too high or should the filter become plugged.

1st Question : Is the above assumption correct ?

2nd Question : Assuming the answer to #1 is YES, then has anyone plugged this bypass to force all the oil through the filter ? What are the potential side effects of doing so ?

I'm not terribly familiar with the GM oiling pattern I just wondered if there was a way to ensure that all the oil gets filtered when I put my new engine back in/together. This failure alone cost me both an engine (wasnt too upset about I guess) and a NEW PT52 Turbo that only had 200 miles on it. I am attempting to take steps to eliminate it from occuring again.

What do you guys think ??

Comments ? Ideas ? Suggestions ?
 
jwaller

jwaller

Evil Genius/SyTy Guru
I have bypassed both bypasses. the one in the block at the filter adaptor and the one in the adaptor itself on the fender.

the only precaution is to be careful with oil pressure when your warming up.

the bypass allows oil to pass the cooler and filter when it's really cold and think making for more flow and less chance of a filter blowout.
 
canadian

canadian

sy in progress
i believe myclone had some good info a while ago about the bypass. i'm sure it's in here somewhere.
 
myclone

myclone

Donating Member
About the only thing I could add is keep in mind what waller says about cold start up... If you block both bypasses then you REALLY should let the engine warm up some before getting the RPMs up or beating on the engine. A high stall TC even at light throttle can get the RPMs up enough to blow the filter apart or rupture the seal with excessive oil pressure.

I personally dont block the bypass(es) completely in anything but a track only engine as ya never know when you just might need to hop in, fire it up, and haul ass. Doing so with a blocked bypass engine might get you ~10yds away before the filter explodes. The bad guys/pissed off wife/pissed off wifes husband/whoever will catch up to you VERY shortly :D .

On the other hand just shimming the bypasses will give you plenty of filtered oil but in extreme situations such as a ticked off wifes husband with a gun, extreme cold temps, or what have you it will allow some oil to bypass the filter so as not to subject it to extreme pressures.

Lastly, the bypasses arent there just in case the filter becomes clogged. They are also there as a "last resort" pressure relief to save the filter, its oil lines, dist gear, oil pump drive, etc in case some type of failure of the oil pumps internal bypass causes excessive pressure in the system. By blocking them you lose this redundant but important function but by just shimming the bypasses you still have some margine of safety but also get higher oil/more stable oil pressure.

HTH
 
Tydriver

Tydriver

TurboLS6 Powa'
Well I read in one of the posts Myclone U recommended using a 1/16th washer under the relief valve... Any idea where the bypass pops off stock ? And what it will be with the modified bypass ??

Any PSI ratings/readings ?
 
myclone

myclone

Donating Member
Tydriver said:
Well I read in one of the posts Myclone U recommended using a 1/16th washer under the relief valve... Any idea where the bypass pops off stock ? And what it will be with the modified bypass ??

Any PSI ratings/readings ?
Click to expand...

Ive never measured what pressure the stock bypass opens but have heard from numerous old school SBC ppl that its less than 10psi. I know thats not much but in the grand scheme of things its not so bad. We as "car guys" keep our filter and oil changed so its not a matter of "dirty" oil being circulated. The bypasses are in there to possibly save the engine and filter should john q public decide that changing the oil and filter at 50k miles is a good idea rather than at ~3k(you would NEVER believe some of the crap john q public does!!).

Anyway, the only way for the oil to be filtered 100% of the time is to completely block the filter bypasses. Thats fine and dandy as long as you give the engine some warm up time at idle RPM EVERY single time its started but IMO thats a PIA for a street engine. So, IMO its a balance between bumping the bypass pressure set point up to force more oil through the filter, cold start RPM, and piece of mind that no matter what the temprature of the oil is I can fire up an engine and drive off without worries of the filter blowing off from too much pressure in the filter.

Unless you block the bypasses completely there will ALWAYS be some amount of oil that bypasses the filter, so basically all that happens when you shim the filter bypass is you are raising the amount of pressure it takes before the oil starts to bypass the filter from the stock level.

So, shimming the bypass helps keep more oil going through the filter but doesnt have the drawbacks of comletely blocked bypasses.
 
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