Racer11

Thinking about Plugging up my bypass valve on my 350 block and thus making all the oil pass through the filter.

If I do this, will it effect my oil flow/pressure at higher RPMs 3,000 and above for example.

and

Will the bypass system in the oil filter defeat my purpose.

540 RAT

I have no bypass valve on my 540 BBC Street/Strip motor. It does not affect oil flow/oil pressure at high rpm. Once mine reaches relief valve pressure at around 5,000 rpm with 5W30 Royal Purple, it holds a rock steady 80 psi all the way to redline.

But two things to keep in mind:

1. With all the oil passing through the filter hot or cold, you don't want a filter that would be too restrictive. So, I use a long 2 qt sized K&N filter, that has no bypass in it either. The extra filter volume prevents the oil having any problem trying to get through when cold or at high rpm, so flow/pressure is never a problem.

2. A similar restriction issue could come up if you run super thick oil like 20W50, especially when its cold. So, I run 5W30 as mentioned above.

Yes, a bypass valve in the oil filter will defeat what you are trying to do. You must get a filter with no bypass in it.

Racer11

540Rat,,,,

So I need to get rid of my 15-40 Rotella Dino----Right ?

My oil pan is a 6qt and a long filter will not fit due to the kick out.

What filters are available that do not have a internal bypass that will fit with my 6qt pan??

Thanks for the advice/help

noonie

All the oem stock filters do not have a bypass in them.
If you decide to eliminate the bypass, then go with a racing filter. Most brands have one, Wix, Fram etc.
They have approx double the microns as the regular filters and can handle the cold flow.
If the old oem canister setup would fit with your pan, that would be my choice.

Solid LT1

I don't run bypass valves. I use a billet oil filter mount because years ago I had a cast adapter fail on me. I also used to have an OEM Chevy cast adapter that didn't have a bypass valve built into it, just a blank area.

Peterbuilt

Hi,
Not sure what we are talking about here, can you tell me how the bypass in the block and the filter work?
Thanks.

yellow 72

540 RAT

Well, personally I don't like to use oil thicker than 5W30 for a lot of reasons besides just flowing well all the time with no bypass. The thinner oil flows quicker to all engine components on cold start-up, when most wear takes place, thinner oil also flows more gpm which lubricates everything better, that extra flow carries away more heat, keeping the internal engine components cooler, and thinner oil also generally makes more HP than thicker oils.

It's pretty much a win/win with thinner oil, but you may well need a high volume oil pump in order to maintain a reasonable oil pressure, particularly at low rpm. I run a Titan gerotor high volume oil pump that moves a lot of oil. And the last thing about thinner oil is that you really only want to use it if you will be using a top quality full synthetic oil that has excellent film strength. I would not recommend using plain old cheap everyday dino 5W30, which is not even in the same league with today's latest full synthetics.

Here's a list of oils that I recommend considering.

The High Performance and Racing Oils on this list (all full synthetic unless otherwise specified) have acceptable levels of all that is needed, and are suitable for Classic Cars, High HP Street Hotrods and Street/Strip cars, as well as many dedicated race cars (including flat tappet setups and those with bronze dist gears):

Joe Gibbs Hot Rod Oil
Royal Purple XPR (Extreme Performance Racing)
Royal Purple HPS (High Performance Street)
Valvoline VR1 Racing Oil (Silver Bottle, this one is dino oil, but is still quite good)
Valvoline VR1 “SYNTHETIC” Racing Oil API SL (Black Bottle)
Brad Penn, Penn Grade 1, High Performance Oil (this one is partial synthetic, but still quite good)
Amsoil Z- Rod Oil

Some of these oils can be found in 5W30, others in 10W30, and Brad Penn is also available in 0W30.

10W30 won't flow quite as quick on cold start-up as 0W30 or 5W30, but is otherwise a good choice.

As for your 15-40 Rotella Dino, that is not an oil that I would use, but I suppose you could try it and just keep a close eye on your oil pressure gauge.

RobbSalzmann

My understanding (limited as it is), is that a bypass in a hydraulic system is design to vent off excess pressure. Since fluids don't compress, it seems that plugging the oil bypass would only force the "bypass" to take place in another part of the system (I'm thinking the filter or the filter o-ring). Once your filter can or o-ring breaches due to over pressure, you've got significant problems.

With that in mind, I'm curious what is the motivation to or advantage in plugging the bypass?

noonie

You have part of it right.
The system relief you are referencing is in the oil pump, set anywhere from 50 to 70psi, well below the ratings of even a basic filter. Filter plugs up and you loose all excess oil pressure thru diverted flow at the pump, no more than set point psi at the filter.
The filter relief or bypass is just for the filter, in case it plugs up, you still have oil pressure, just with unfiltered oil.
It usually bypasses the filter when the engine is cold, at very high rpm, partial or plugged filter, or too heavy a weight oil for the filter flow.

If dumping the filter bypass, the ideal scenario would be to have any pressure drop activate an alarm or alert light.

Solid LT1

I use 10-40W Brad Penn oil in our 70LT-1 over 7K miles with no bypass and no problems. Oil filters are K&N. Start-up usually sees 65-70psi then 35psi after being warmed up. Change your oil filter sooner than 6K miles and you'll be OK.