408 oiling advice

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Outasite

Outasite

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After many trouble free years of fun from my 671 topped 340 it’s time to build a new engine.My choice is a 99 magnum 5.9 block, .030 over, filled with a forged 4” crank, H beams with 2000 bolts,Mahle 34cc forged pistons,Hughes girdle and Kevco pan.In the middle is Bullet custom blower hyd roller cam.And topped with a pair of trick flows.I want the oiling to be as good as the rest of the engine.So far I have all the 1/2” drilling at the rear,including the rear main cap and pump done.All five cam feeds have been tapped and plugged at the main saddles and a .125 feed hole drilled in plug.All sharp corners that I can reach in the 1/2” feeds have been rounded off.I’ve spent the last few hours reading the guitar Jones thread from long ago.I got to page 22 or so, and decided the last ten or so pages was a bit of back and forth exchange of
ideas .Anyway I’ve decided to do the crossover mod.I’ve got hydraulic roller lifters,oil through push rods,and Harland Sharp rollers on top.So after all this,my questions are,what is the preferred drill size for mains to lifter galley.9/32 or 5/16? Is it proper to restrict oil to #5 cam bearing? And does the infamous front main feed block off, go on the right or left side Feed to the galley?
 
I am a firm believer in the A&W crossover tube modification. As for the passage from the mains up to the main oil galley you need to see what it already is. I've had them that were restricted and I had them that were already 5/16. You got to watch for that step in the passage on the earlier blocks. I don't believe the Magnums have the step. But if it does drill it out.
You are plugging the right side (passenger side) passage in the front. The easiest way is to set a freeze plug in the oil galley to block the front passage.
Read the last 10 pages.
 
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Block the oil to the drivers side oil gallery either by putting a set screw in the feed under the number 1 main bearing or use a cup plug in that oil gallery, driving it in from the front (where the cam plate bolts on) until it goes past the oil feed coming up from the main bearing.

All that pressure side works helps, but 95% of getting the oiling better is increasing the suction side of the system.

Center sump pans have enough design flaws it’s not funny, two of them being that it’s hard to get an effective baffle in the pan for both acceleration and deceleration, and the fact that the oil pump is so far from the pickup screen it becomes a big restriction.

The longer that tube, the worse it gets. Getting as much area at the tube is the biggest gains you can get.

It’s gotten better today than it was back in the 1970’s and 1980’s because oils have gotten so much better. Sucking that thick assed oil up that small long tube was a big problem. If you are using a quality oil that isn’t a 50 grade that helps a bunch.

Gerotor pumps are different than spur pumps in that a spur pump has a more consistent, smoother, out put than the gerotor pump does.

If you look at the two side by side you can see the 4 lobes on the gerotor hold much more volume per lobe than does the spur pump. So for each Revolution of the gerotor pump (even if the gerotor and spur pump put out the same GPM) needs a bigger volume to fill the cavity.

So spend some time on the suction side because that’s where the biggest, most important gains come from.
 
Post 5 shows how I increased the suction flow on the pickup tube. May not work on a stroker crank motor.

www.forabodiesonly.com

My take on the oiling system crossover tube for the small block

This is a combination of my thoughts and ideas taken from the Guitar Jones oiling system modifications thread. If you have some input that would help along these lines and to clarify some of the thinking you're more than welcome to post but if you think that you just need to post negative...
www.forabodiesonly.com www.forabodiesonly.com
 
Jadaharabi said:
Post 5 shows how I increased the suction flow on the pickup tube. May not work on a stroker crank motor.

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Click to expand...

Even a small increase in section on the suction side is a pretty substantial gain.

What you did certainly helped, but like you said it might not clear a stroker but if one is a it resourceful I’m betting it can be done.

In one of the Chrysler engine books there are a couple of graphs that show the increase in pump flow with bigger suction side piping. I forget which one it is.

This situation is buggered up by the center sump pan. If you can find and use the Milodon Super Stock pan (which is rear sump) you can fit a 1 inch pipe for the suction side right into the cover of the pump. Milodon made the covers. And if you really wanted to add some more area you could add a second pick up in the original location.
 
Kevco makes a pickup that replaces the plate on the back of the pump but you need their rear sump pan. This is on my 408 truck application.

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Rat Bastid said:
Even a small increase in section on the suction side is a pretty substantial gain.

What you did certainly helped, but like you said it might not clear a stroker but if one is a it resourceful I’m betting it can be done.

In one of the Chrysler engine books there are a couple of graphs that show the increase in pump flow with bigger suction side piping. I forget which one it is.

This situation is buggered up by the center sump pan. If you can find and use the Milodon Super Stock pan (which is rear sump) you can fit a 1 inch pipe for the suction side right into the cover of the pump. Milodon made the covers. And if you really wanted to add some more area you could add a second pick up in the original location.
Click to expand...

Post 7 in that thread is the milodon bottom plate.

1540770082593-234802957.jpg


The Chrysler kit car motor used a duel line pickup system.
 
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Be very careful with that kevko pickup becomes mine was warped badly.Mine was so bad I could see it.I bolted it gently to the oil pump and it couldn't be turned.I had machine shop surface it.
 
Good to know, my Kevko pan is a mid sump with a trap door.It uses the std 3/8 pipe pickup.I measured the inside of the pickup at the pump today. .465” Tomorrow will be opening the pump to 1/2 NPT and depending on the ID of the tube possibly fabing up a new tube.There is no room under the pump for a pickup in the cover plate.
 
Lots to be gained here.The choking point is the welded fitting that threads into pump,measured .465 however the ID of the tube is .620.So just changing the input fitting to 1/2" npt by opening and threading the pump housing to 1/2" will increase the flow capacity by more than 50%

IMG_20230302_160251496.jpg
 
Update,took last summer off to do some boating.But did collect the rest of the parts I will need.This includes billet flywheel,center force clutch,high capacity Holley in tank pump,and thick 5.9 Cummins motor mounts,and small denso mini alternator,etc .Think I got everything I need,just a little short on ambition.sittin in the chair making race car sounds ain’t gettin it done:rolleyes:
 
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