Why would need a 30 psi bypass? If the oil pressure is above 30 psi it will bypassing right??

Would you not want all the oil going thru the oil filter?

If there is restriction I would think it would be the oil filter [dirty] which should NEVER happen unless there is a failure fixing to happen. If this is happing ,you want know it because its bypassing with all the metal going thru it.

Even the 30 lb valve, if you push on it it takes way less than 30 lbs to open it. Those valves work off of differential pressure. The valve has oil filter inlet pressure on one side and oil filter outlet pressure on the other.
Regardless.
I block them off by threading the hole for a 1/2 NPT plug. Never had any problems.

When the difference in pressure is greater then 30 psi is when the bypass opens. As long as filter is flowing oil you would be hard pressed to have a difference of 30 psi between the filter in & out.

The main reason for the 30 psi bypass is when you are using an oil cooler and/or remote filter. The oil cooler, fittings & hose will have a restriction & it is not hard to get a restriction of 11 psi, thus the reason for the 30 psi bypass. If the 30 psi opens you have some serious problems with your filter or oil cooler but at least your motor will be getting oil, just not clean and cool

I did not add. I use a good quality Wix oil filter with a bypass built in when blocking off the engine mounted bypass. .

Cooltoys- Listen to Macdad & Turbojack....use the 30psi valve or plug! I found this out the hard way.

Dang!! I knew if I kept at this thread I'd get some good responses. So the downside of using the 11# bypass is poor filtration but really good flow no matter what? Not being sarcastic, just fried 2 GenIV motors and trying to get to the bottom of this. If I keep my oil changed reg. it seems better to have terrible filtration?? What do I know. OK, both would be better but I need to KNOW I'm getting both. You guys ROCK, That's why I'm here. Thanks

cooltoys, I've been fighting this myself this season. The downside of the 11 lb valve is not only possible poor filtration. The 11 pounder could also limit oil flow to the cooler, which may result in higher oil temps {got oil temp gauges??}. I've posted on this same subject on OSO and on S/W. And the consensus is, change the side bypass valve to the 30 lb, and remove the center one.

I see. Gonna look at the routing tommorow and consider what you're saying. Thanks.

I have a temp gauge for oil,, but it never moved much until after I fried my bearings.

I removed the center valve which had been installed when the motor was rebuilt and replaced the one in the pad with the 30psi valve. I'm going to install a oil temp gage to determine if I need to get a larger cooler.
It did seem to show a slight drop in operating temp and a slight increase in oil pressure after a hard run, but I still need to install a oil temp gage to be sure of whereI'm at!