Inliners International Forums General Discussion Engines Oil bypass valve opening pressure?

Hi everyone,
I've gathered from reading on here that most remove and plug the oil filter bypass valve and just run through the filter. Obviously they are not incredibly reliable as GM also stopped putting them in the newer Vortec V8's and started putting them in the oil filters instead. That way they are replaced every time you change the filter. I thought this would be a good concept to use in my engine.

I found a filter with the exact same specs (height, width, seal size, etc) but it has an oil filter bypass and anti-drainback valve built into it. Should help build oil pressure sooner as well. It's bypass valve is 7-9 lbs, which seems to be similar to any others that have had them. The number is a Wix 51072.

Does anyone know what pressure the original opened at?

Is anyone else running these and do you think it'd be a wise decision?

It depends on if you will be driving it in cold weather.

I personally plug all the filter bypass's and use a non bypass Wix filter. Wix 51060 it does have a anti drain back valve.

Been running the 65 Chevelle wagon this way since putting it together a few years ago.

If it is real cold (30-50), I try and let the engine warm up before taking off. I don't drive it in anything colder than that. If it did get driven that cold, a bypass filter would be used.

Next question...

Is there any reason not to use a bypass filter?

I understand the original could fail/clog/etc, but when you are replacing with every oil change that should eliminate the problem.

Any time you can allow unfiltered oil to circulate thru your engine is never a good idea.

Understood, but there has to be a reason GM has had it and continues to have it. Not trying to start a battle or anything, just thinking out loud...or typing out loud...

It should only open up when there is 7-9 PSI difference between inlet and outlet (in my understanding). If there is more restriction than that, you would be under the assumption that the oil filter is clogged for whatever reason and the engine will soon be starving of oil pressure. Pressure valve opens up to allow the engine to maintain proper pressure, although your oil is now no longer filtered.

So what's worse, not enough oil pressure or dirty oil? You have to assume that you have something already in your oil causing the filter to be clogged, and that same oil would then be distributed to bearings throughout your engine if the valve opens... but again, vs having no oil pressure.....

Almost a chicken vs egg conversation!

The bypass valve is also one of those things that when it does finally work, the damage is already done. If the filter has stopped up and the bypass is functioning, how much trash passed through the engine before it did eventually bypass. Too little too late by this point.

It was likely created by the enginauts(engineers that think their astronauts)at GM to save a warranty claim, assuming your idiot light didn't burn out and you were able to catch it in time.

Well, I'll probably still run the filter with it built in. Doesn't seem like it could hurt anything and maybe it will function as designed and save me, although I hope my filter never becomes that clogged regardless!

Becoming clogged is the worst case scenario, and many people envision a clogged drain in a sink as being what they are comparing this too. It actually only takes a small piece of trash like some gasket sealer or a piece of gasket to stick into the valve preventing it from closing fully and oil is bypassed at this point because the valve is only partially closed/open. This is very common on freshly rebuilt engines where you have a lot of break-in going on and a lot of left over stuff getting into the engine. You'll probably be ok.