And I say oil filtered through a rock catcher is better than unfiltered bypassed oil.
Bypass in filter and block……?
- Thread starter DHBWA
- Start date
Those engine internal bypasses are usually a very high PSI to active...I've seen one stuck in a jet ski and it would blow the o-ring off the oil filter at anything over idle, everything was fine after the bypass was replaced.
Back in the 70s & 80s, with our drag race chevy engines, we would drill, tap, and plug the bypass in the oil filter to engine block adapter, and run a oil filter with no bypass. But the oil pump had a bypass.
That sounds like the oil pump pressure relief valve malfunctioning, not the filter bypass valve.
Could still damage the filter doing that because the oil pump pressure relief valve doesn't control the dP across the filter media and center tube. Only the filter bypass valve does that. Too much dP inside the filter can implode the media and center tube. One main reason the filter bypass exists is to prevent filter damage when the dP gets too high.
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- May 9, 2023
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Neither is good……but dirty oil is better than no oil. That’s the reason for the redundancy
Why were guys doing that modification thinking it was a "good thing" to do? Some guys probably damaged or lost engines doing that when the oil filter imploded from high dP, causing the oil pump to spike to pressure relief and possible media going into the oiling system causing oil starvation to the engine.
Collapsed Center Tube Tech Document from Fram:
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Yeah, that is what I'm talking about...thought that was what the OP was referencing?
He's talking about the oil filter bypass in the engine block, like a lot of GM built engines have. That's not the same bypass as the oil pump pressure relief/bypass valve.
Ole chevys have great oiling, so we got away with itWhy were guys doing that modification thinking it was a "good thing" to do? Some guys probably damaged or lost engines doing that when the oil filter imploded from high dP, causing the oil pump to spike to pressure relief and possible media going into the oiling system causing oil starvation to the engine.
Collapsed Center Tube Tech Document from Fram:
nothing bad ever happened with me or any of my racing friends.
I worked at a speed/machine shop.
A lot of parts back then came from the junk yards, got massaged, and became parts in our race engines.
Most of us were bracket, super street, super gas, and super comp racers, flat tappet cams, VP C-12 fuel, raced every weekend, and sometimes at 2 different tracks in a weekend.
One of my friends would even modify the bypass spring in the oil pump so his max pressure would be about 25 psi. He ran his engine at higher rpm (7500) than the rest of us.
We would freshen our engines in the winter when the tracks closed.
I eventually ran a remote Oberg 6" TattleTale filter setup w/60 micron stainless screen, no bypass. No issues
But it is filtered oil. Its
been filtering for 10's of engine hours. It just wasn't filtered for those few seconds
All of our race engines were killed by overstressing, not by bearing streaks from junk.
I ran an adapter and dual remote large filters behind the headlight opposite the battery tray. Napa used to make the hydraulic hoses for you. Just dumb luck and primarily driven by necessity as the header tubes were crowding the canister.
I will say you don't want bearing junk in the oiling system - it turns a weekend cleanup/refresh into a full rebuild.
- Ken
