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Oilfilter bypass valve...(Q for engine-builders)

Fred_M1010

Fred_M1010

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I'm building a 454 engine for my Camaro.
And have gotten different advices about plugging the bypass valve.

This book says not to plug it, if it's not an all-out racing engine:
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But I've heard other people say, it's ok to plug it, if you use a high flowing race-filter.

I'm thinking it would be good to always have filtered oil, if I get a cam-lobe failure or something like that,
so it doesn't distribute the shavings to the whole engine.
But on the other hand, I'm a little concerned not to get full oil-pressure, until the engine is warmed up.

I only drive the car in the summer.
And I'll probably have 450-500hp@5500-6000rpm

What are your opinions?
 
DO NOT plug the bypass if this is not a race engine that gets oil changes every other run. The ONLY TIME the oil will "bypass" is if the filter becomes clogged or too much of a restriction. If you plug the bypass and the filter becomes too dirty or has a restriction for whatever reason it will blow the filter off the engine. I would rather have no filtering over a blown apart oil filter any day. Engines up until about 1956 never had a factory oil filter and they have survived. :deal:

Keep in mind i have been building engines for 32 years, professionally for the last 22 years.
 
also heard when cold oil DO NOT REV THEM UP thick oil and cold will pop a good filter also.

race only i say.
 
Hmm, I guess unfiltered oil is better than none at all...
My machine-shop told me that as well, but I couldn't stop thinking about it.
The spring in the bypass-valve seems so weak, it feels like it would be open most of the time.

But I guess if I use a good high flowing filter I minimize the pressure drop over the filter,
And that way I reduce the risk of the bypass valve letting the oil through...:thinking:

Thanks for the input!
 
Don't use a HV oil pump in a chevy engine, especially not a big block. If you want higher pressure, up the spring rate on the by-pass spring in the pump it's self. You can get the Z28 (white?) spring for the stock pump that will increase the pressure. With HV, you get added windage as well as oil pooling on top of the heads.

People confuse pressure with flow. Just because you have good pressure, does not mean you have good flow. The passageways in the engine were designed to work with a specific flow, increasing the volume of that just increases stress on the engine. My Dad built drag racing/high performance engines for years on stock oil pumps. The motor I built for my Camaro (350cid) turns 6800RPM between the shifts and uses an oil pump that came factory on the block in 1976. If you don't have good pressure with a stock pump, your clearances are way off or you've got something wrong.

Also, think of the horsepower that it takes to turn the pump. The power has to travel through the timing set, down the camshaft, through the gears to the distributor and down the oil pump drive shaft. The extra power needed to turn a HV oil pump is adding stress to all these parts, increasing wear and the chance of failure. I remember a little blurb in Hot Rod magazine where they were playing with a mild 350 on the dyno. They were using a stock pump in it and a Z28 spring and noticed the pressures getting too high at the top of the RPM band. They clipped a coil off the spring, dropped ~10PSI at the top of the power band and picked up ~5HP.

The only place I'd consider using a HV oil pump is if I was tapping right above the filter for a pair of turbo chargers or an externally oiled super charger such as the Vortech series.
 
Thanks for the advice, but I've never really even considered getting a HV-pump.
 
There is no need for a high volume OR high pressure oil pump. I run a stock oil pump in my engine and it has 60 lbs oil pressure hot or cold +/- a couple lbs.

For anyone reading this, if you install either a high pressure or high volume oil pump you MUST install the intermediate shaft with the attached steel sleeve otherwise the plastic sleeve can break and do alot of damage.
 
Don't plug the bypass. Just make sure normal operating pressures at the bypass are kept low.

PurePower sells a reusable billet aluminum cased with stainless steel mesh filter that lowers pressure and increases engine efficiency. It can be reused infinitely. It also has internal magnets to catch the fine metal particulate.

Amsoil sells a bypass filter that filters oil down to and marginally below 1 micron. It feeds the engine super clean oil, dramatically reduces wear, and allows you to go 20000-30000 between oil changes when using full synthetic and monitoring oil quality.

When using these two in conjunction, your engine couldn't be happier. They will also easily pay for themselves in saved oil, filters and fuel.
 
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Plug it and don't run a POS fram and change your oil when you are supposed to and you will be fine. I know people running all sorts of stuff plugged in cars, trucks, boats, and I've yet to see a problem. Mine is plugged in my engine. Oil presure is fine when it's cold as long as you have a decent filter ( I run delco PF1218).

And you aren't going to blow the oil filter off or up or wherever. That is why there is a spring in the oil pump, any oil above the pressure which that spring is calibrated for will just cycle around in the pump and not go anywhere. So if you oil filter get's plugged (because you didn't change it), or your oil galley even with a filter bypass), the oil pressure will drop to zero (at the gauge, the pressure up to the blockage will be the max the spring allows, 80 or 100 or whatever it is with that particular spring/shim combo) and the oil will cycle inside the pump. This is obvously not good for your engine and you need to shut it off immediately if that ever happens, but it won't blow your oil filter up.

My engine machinist usually plugs them for many of his customers (unless it's a bone stock rebuild) and he has been doing that for decades.

The bypass is for people who run cheap filters and don't change their oil when they are supposed to. Your engine will be happier with 100% filtered oil.

And if you run a FRAM filter you probably will have a problem eventually.

One thing I did do is make sure I have an idiot light (LED) in addition to my gauge because many times you have to watch the dirt (assuming you are offroad) and not the gauges.
 
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Agreed with folkenheath. You can plug the bypass if you have a good filter, pressure gauge and reasonable oil pressure. But, it takes an educated driver to deal with the possible issue and ongoing maintenance. If a Fram filter gets installed on a plugged bypass things go bad. BTW, my oil pressure is 75lbs cold with no flow issues and 50 PSI warm, 25 psi at idle.
 
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