Moparts

Big block engine priming question

Posted By: 6PAX

Big block engine priming question - 05/11/23 03:49 PM

I was priming my new build engine today (on the stand with the valve covers on to avoid a mess) and when I first started priming it I was only getting oil on the passenger side (running down the block on the inside). I don't have any help to run the drill while I turn the crank so I just started turning it in small increments and then ran the drill again. I eventually got oil on the driver side but only from all of the exhaust rocker arms, nothing from the intake rockers (at least not enough to flow running down the block). So I put it back at TDC and ran the drill again and like the first time there was oil flowing on the passenger side. However, what I didn't notice the first time was the oil was only coming out of the exhaust rockers just like on the driver side. Is this normal?
Posted By: Cab_Burge

Re: Big block engine priming question - 05/11/23 04:08 PM

What brand and type of rocker arms, ductile iron, extruded aluminum, needle bearings or not?
Standard 440 type rocker or are they offset intakes for the bigger M.W. size ports for the Indy 440-1 type heads?
Posted By: 6PAX

Re: Big block engine priming question - 05/11/23 07:16 PM

Comp Pro Magnum roller rockers on Edelbrock Performer RPM heads.
Posted By: rickseeman

Re: Big block engine priming question - 05/11/23 09:09 PM

It will prime the other side when you turn the motor over some to line up the oil holes in the camshaft.
Posted By: DrCharles

Re: Big block engine priming question - 05/11/23 11:11 PM

Originally Posted by rickseeman
It will prime the other side when you turn the motor over some to line up the oil holes in the camshaft.


To add to this - the oil hole in the cam journal only passes by the head passage hole as it turns, for a brief "squirt" every other revolution. Unless you have the cam lined up with the hole while priming, no oil will flow at all.

Of course, if you have a grooved #4 cam journal (my Mini-Express mushroom came that way), then the oiling is continuous and cam position doesn't matter.
Posted By: A727Tflite

Re: Big block engine priming question - 05/12/23 12:10 AM

Read the opening post - he is getting oil to each side but not all the rockers are getting g oil in each bank, just the exhaust.
Posted By: DrCharles

Re: Big block engine priming question - 05/12/23 12:18 AM

Originally Posted by Transman
Read the opening post - he is getting oil to each side but not all the rockers are getting g oil in each bank, just the exhaust.

OK, I read it. I don't see where you posted any possibly helpful information though. Now what? whistling

What happens if the rocker shafts are on upside-down? work Or would that cut off oil to all the rockers? I've never tried it.
Posted By: Stanton

Re: Big block engine priming question - 05/12/23 12:23 AM

The engine is on a stand so tilt it to one side a bit and take off the opposing valve cover. This should prevent oil flowing down the sides of the motor. Now prime it and see where the oil is coming from. There is really no logical explanation for only exhaust rockers getting oil - even with "offset" rockers the only things that are offset are the arms of the rocker, the body is still in the same location on the shaft.
Posted By: metallicareload

Re: Big block engine priming question - 05/12/23 12:26 AM

I don’t think it would make a difference, but are the rocker shafts properly orientated?
Posted By: A727Tflite

Re: Big block engine priming question - 05/12/23 12:45 AM

Originally Posted by DrCharles
Originally Posted by Transman
Read the opening post - he is getting oil to each side but not all the rockers are getting g oil in each bank, just the exhaust.

OK, I read it. I don't see where you posted any possibly helpful information though. Now what? whistling

What happens if the rocker shafts are on upside-down? work Or would that cut off oil to all the rockers? I've never tried it.


Comment wasn’t directed at you - several people made the same basic comment.

As for useful suggestions, I would look at the intake rocker arms and see how they are drilled for the oil passage and even compare them to the exhaust.
As for shafts upside down, that shuts off oil to all the rockers. Unless it has a gigantic #4 pedestal hole. I guess anything is possible.
Posted By: 6PAX

Re: Big block engine priming question - 05/12/23 01:20 AM

Originally Posted by metallicareload
I don’t think it would make a difference, but are the rocker shafts properly orientated?


Yes, the shafts are on the right way per the Comp instructions. The oil holes aren't at an offset angle from the shaft centerline like on the factory shafts. They are in line with the shaft bolt holes and they are facing toward the head.
Posted By: Uberpube

Re: Big block engine priming question - 05/12/23 02:58 AM

Mine came coated with some kind of protective shipping wax mung that was blocking some of the oiling holes. I washed them in lacquer thinner and had to take a torch tip cleaner to some of the holes. Also if I recall correctly ,the adjusters are out too far it blocks the push rod oiling hole.
Posted By: Cab_Burge

Re: Big block engine priming question - 05/12/23 04:54 AM

I started having the #4 cam journal grooved about .030 deep with the same width as the oil hole in the cam on all my solid roller cam motors so it oils the rocker shafts full time. I will add oil restrictor as needed depending on the rocker arm type and valve spring pressures they have (the extra oil helps cool the stout roller cam valve springs also) wrench scope up
Posted By: Stanton

Re: Big block engine priming question - 05/12/23 12:54 PM

Quote
The oil holes aren't at an offset angle from the shaft centerline like on the factory shafts.


I find this unusual. Every shaft I've ever seen - regardless of manufacturer - had the holes offset. I don't suppose it matters but just sayin' ...
Posted By: 6PAX

Re: Big block engine priming question - 05/12/23 02:26 PM

These are the shafts.



Attached picture 1079-2_1.jpg
Posted By: AndyF

Re: Big block engine priming question - 05/12/23 02:33 PM

Take it apart and examine the parts. You'll figure it out.
Posted By: RO23dave

Re: Big block engine priming question - 05/12/23 03:53 PM

aren't those shafts supposed to have the banana grooves in them, so you know that they're oriented right? Plus no matter where the rocker winds up they'll always get oil. Dave ss/ea #1355 fury
Posted By: Torq37

Re: Big block engine priming question - 05/12/23 09:07 PM

If you end up knocking out the soft plugs from the ends of the shaft-- Melling MPC-48 plugs fit better than Dorman. The Dorman plugs go in okay but for whatever reason it doesn’t take much force to push them back out. Discovered this by accident.
Posted By: rumblefish72

Re: Big block engine priming question - 05/14/23 02:41 AM

Oh the factory oiling system priming the rocker arms headache. I would try to break things down and check step by step. First is to establish if the issue is in the block oiling path up through the rocker support stand. This doesn't sound like your issue but we're checking everything. Or if the issue is in the rocker shafts out to the rocker arms. With rockers still on so you can observe pushrod movement, spin engine until #6 is coming up on the compression stroke, spin through compression until the crank is at TDC on #6. Now take the rocker shafts off. Gently prime the oil pump with drill motor while watching for oil coming up out of the rocker support stand that has the oil feed. Unfortunately, my notes don't mention which (passenger side or driver's side) side is lined up at this position. I would move the crank a few degrees either way to see if oil flow increases as you get the oiling holes exactly aligned. And if you spin the drill fast, oil will shoot through the rocker shaft support and hit the ceiling so spin the drill at low RPM. I would pick a drill RPM that produces good flow up through the rocker stand so you know what type of drill RPM produces decent flow. With a baseline established for oil flow on the first side, spin the crankshaft 270 degrees COUNTERCLOCKWISE to #8 TDC. Spin the priming drill at chosen RPM from testing the other the side and watch for oil flow coming out the rocker shaft support. If all looks good from there, reinstall rocker rocker shafts and prime some more with alignment still intact. See how oil comes out of shaft at each rocker. Spin motor clockwise 270 degrees, prime other rocker shaft and watch of oil flow pattern. If all looks good move on to the next debug step below. I guess that if the cam centerline has not been checked after installation and you are way out, you might not see any oil at either of these alignment positions. Cams for BB Mopar should all be drilled the same position for the oiling passage alignment WRT TDC on #1 as stroke transitions from compression to power stroke. But in my 45 years of Mopardom, I've seen lots of things that don't check out properly so maybe this procedure doesn't work on your specific cam. I've also seen friends trigger lock the drill and zip tie it to the manifold so it won't spin and then turn the motor over slowly watching for the oil gusher out of either side.

Before we get to additional debug on the shafts and rockers, thanks to the guys at Muscle Motors (RIP) for taking the time to walk me through the rocker oiling system cam alignment procedure!

It does concern me that you are seeing good oil flow on the exhaust rockers but not on the intakes. That doesn't make much sense. The oiling holes for the rocker shafts are all in the same location and size so if one rocker is seeing oil coming out from around the shaft, they should all be seeing that same oil flow. Just to double check, when you say no oil to the intake rockers, you're talking about where they locate on the shaft and not if they are squirting on the adjuster. Dribbling on the intake adjuster could definitely be different than squirting on the exhaust lash adjuster especially with offset intake rockers. The only thing I can think of is that the exhaust rockers shaft ID is machined too big on all of them and under light priming oil flow, the exhaust rockers gush all the oil pressure out where the shaft goes through and the properly fitting (tight) intakes don't squirt anything. So check to see how each rocker fits on the shaft. That's the best I can do for you. My guess is that if you step through this debug, you will find an issue somewhere. Good luck and remember that perseverance is what will get you through to the Mopar promised land of good rocker oiling!!

Oh, and quick PSA, I'm sure everyone here on this board knows how important this is but NEVER go under a car that is not properly supported (jack stands). A local kid graduated with a BS in ME from Dayton a week ago. After graduation, he needed to fix some things on his car so he could drive back to Pittsburgh. The car was not properly supported and it fell on him crushing him. His funeral service was held at my church earlier today. I'm in the process of touching base with all the young guys I know to make sure they know this critical rule. Sometimes newbies don't know this rule or think it's ok to work on a car supported by the factory (put the spare on) trunk jack or just a good sturdy rolling jack from one of the suppliers ... this can get you crushed. RIP Ian.
Posted By: Stanton

Re: Big block engine priming question - 05/14/23 02:21 PM

Am I the only one who thinks those are awfully big oil holes ?!?!?!

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Posted By: johnzgarage

Re: Big block engine priming question - 05/14/23 05:20 PM

Do you have the correct amount of oil in the engine ?
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