Porting the oil passage from pickup tube to pump in B/RB block

[natas33]

I did this for the first time, as i read recommended by someone who's built many mopar bb's including 1000+ B1 motors, he was convinced that upgrading to 1/2 pickup is a waste of time unless the block oil feed is ported, because the the hole in the block to the pump is a lot more restrictive than even the 3/8 pickup tube. I think he's right, as looking at the block passage, it's basically two straight holes drilled which meet each other on a 90 degree angle, and smaller diameter than the 3/8 tube. So I ported the block oil passage out heavily, created a nice radius for the oil to flow between the pickup tube and oil pump, and ported the entry out to suit the oil pump. Still running the 3/8 pickup and seeing 80psi just above idle with a high volume pump. When I spun up the oil pump with an electric drill pre start the oiling to the valvetrain seemed extreme.

I think this is a good mod for any performance B/RB build. That said i'll be putting on a milodon dual line with swinging pickup when upgrade the cam to go over 7000rpms. But for now enlarging the block passage seems like a good idea. I built a couple in the past without enlarging the block feed, including one with 1/2 pickup mod, and never saw this much oil.

 

[jag_mopar]

it is always a good idea to check the oil galleys for slag from casting etc. they should be checked before a rebuild. you may not want to go too far as you may open a hole where you dont want.

JAG

 

[gtxtra361]

any pics would be interested in seeing how you did it so i have a guide to do it to my 512 stroker

 

[natas33]

any pics would be interested in seeing how you did it so i have a guide to do it to my 512 stroker

I didn't think of taking pics, the engine is already in the car running. I basically used an air hand held die grinder with a long metal grinding bit (sharp ended point) and got in both sides of the oil passage and ported a big radius on the 90 degree bend (facing the rear of the block). I removed a lot of cast iron, metal shavings everywhere. you cant really go wrong unless you slip and damage the pickup tube threads.. but I ported out most of it from the oil pump side and finished it off carefully by entering from the pickup tube side, and also enlarged the entire hole after the tube threads. the block and oil passages will need thorough cleaning afterwards. blowing them out with compressed air first is always a good idea before the block is acid dipped.

imo for anyone using a factory pickup tube in the block either 3/8 or 1/2, and not an external oil pickup, porting the passage between the oil pump and tube is more beneficial than enlarging the main gallery feeds or anything else. as it is a big restriction. so far so good, im impressed with the pressure it's running using an out the box federal mogul HV pump, not their high pressure version.

 

[Meep-Meep]

It can't hurt to relieve some of that material but too much metal removed in the wrong area might make it easier to crack when the pick up tube goes in. Being cautious where and how material is removed should prevent any problems.