Need some help, oiling issue 318 la block with magnum heads

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janthonyg

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Hello everyone, im new to the mopar world on my second build and have run into an issue with the oiling on my 318. i have a 91 block with some new cast magnum heads and a comp cam valvetrain. the issue is that only some of the rocker arms are getting oil (magnum style arms not shaft la). all of the rockers on the driver side oil fine but on the passenger side rockers 1,3,6, are not oiling but the rest are. i have rebuilt this engine and everything is new. i have also swapped out the lifters twice and same problem. has anybody seen this before? ive cleaned the oil galley all the way to the filter and found nothing.
 
The old LA blocks oil through the head, the magnums oil through the lifters and hollow pushrods. Are you using AMC hydraulic lifters and hollow pushrods? Search hot rod magazine, they did a magnum head swap on a LA 318 and mention the oiling differences as well as the part number and length of pushrods used for their build
 
Yes i am using hydraulic oiling lifters and hollow push rods. The issue is only on those 3 rockers and i have checked to make sure the pushrods are not cloged.
 
I will be following along as I am planning on putting magnum heads on my LA 318. I'm sure on of the experts here will have the answer for you.
 
Have you turned the motor over while priming it? In certain lift positions the pushrod may not oil the rocker.
 
I have not but ive take the valve cover off with it running to check the oil for assuming it would have the same effect.
 
L4staero said:
Have you turned the motor over while priming it? In certain lift positions the pushrod may not oil the rocker.
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I have not but ive take the valve cover off with it running to check the oil for assuming it would have the same effect
 
L4staero said:
Yes sir it would. Prime it with a drill and see if the lifter pukes oil with no pushrod in it
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Ok i will try that and look for that galley plug awg329 mentioned i am taking off the intake manifold off this weekend.
 
Best picture I could find.
IMG_1567a.JPG
 
The distributor side rear gallery plug effects the drivers side pressure most and the problem is reported on the passenger side; if that was the cause, it would likely cause oiling issues in all of the lifters. Still check it, and the front gallery plugs, but I'd be looking at other issues too

This may be a long shot but...... If the lifters have been swapped and the problem persists in specific positions, then it may be in the oil holes in the side of the gallery that provide oil to the lifters. The lifter bores are bored down so that they partially intersect the side of the oil galleries; the result is a small, oval shaped opening in the side of each lifter bore. This has to be big enough so that the 'waist band' (the recess around the body of the lifter) intersects the hole in the side of the lifter bore.

Check these holes in the sides of the problem lifter bores and see if they are smaller than the rest. Sometimes the stepped drilling process in the oil galleries will result in some size variation. Then measure how far down the waist band's lower edge is going down into the lifter bore and make sure it is getting down far enough to be exposed to the hole inside of the lifter bore to get pressurized oil, at least when the lifter is at the bottom of its travel.
 
Hello everyone. Thank you for all your imputs and sorry it took me so long to post but at last i have found the problem. Apparently there were a few imperfections in the heads where the pushrods run through that were just bearly pushing against them and causing them not to sit right on the lifter. I ground them down and rounded the and everything is good. So if anyone is doing the magnum head swap you may want to just grind the pushrod holes just to be safe.
 
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