Another Engine Question

[mopar71]

I am priming my engine and was wondering if anyone here has done it? I am priming my oil pump and was turning the drill counter clockwise,the shaft of the primer got harder to turn,I am asuming it was because the lifters were pumped up.The question I have is does the engine have to be spun at the same time.I dont have any help so I primed and then stop to turn the engine.I do not see any oil at the top end yet and that is my main concern.Does anyone have any suggestions.

[72RoadRunnerGTX]

I was a bit surprised at the amount of torque that it took to drive a freshly primed oil pump. The ½” drive drill motor almost twisted out of my hands when oil pressure suddenly came up. It shouldn’t be necessary to turn over the motor while priming. I think I would continue to prime until oil is present at the rocker shafts though. Being the highest point in the oiling system would make it the last place where air is purged from. Priming is not meant to pump up the lifters; only to purge air from the oiling system so that you have oil pressure immediately at initial start up. With oil pressure, the lifters will pump up almost instantly at start up. I highly recommend molly lube on all rocker and push rod contact and pivot points as well.

[Smellslike1974]

so all we need now is a pic of a white engine.
nice motors guys

[mopar71]

Thanks, I saw air coming out of the lifters,thats why I know the oil is at that point, You are right about the effort I killed 2 of my cordless drill batteries trying to turn it. My wired milwaukee works great at turning the shaft. I will keep trying till I see oil at the top or I was thinking of maybe removing the rocker arms and then see if oil reaches the top. Nice sixpak!

hey smellslike1974,maybe you should paint your engine white

[Smellslike1974]

i actual;ly thought of doing that,but everyone tells me it would get dirty,ofcourse its an engine,and its no difference if i painted it a lighter blue or orange.ha ah

[1bluegtx]

You have to slowly move the crank while you are priming so the oil passage in the cam lines up with the oil passage to one head.You will see oil come out of the rockers.Then move the crank until you get oil out of the other head.This way you will know the passages are open and you are getting oil to the rockers before startup.

BRIAN

[mopar71]

I will have to get someone to help turn the engine while I prime ,Thanks

[72RoadRunnerGTX]

On a big block Mopar, I believe the number 4 cam bearing has a grove cut into it that provides oil passage to the rocker feeds regardless of the cam position. If this bearing is installed with its holes misaligned with the block, it will block the oil feeds to the heads. I think you will find that oil will arrive at both rocker shafts without rotating the crankshaft. That will indicate you have accomplished the primary reason to prime the oil system in the first place and that is to purge air from the system and avoid starting with dry bearings.

[mopar71]

So if I am priming,and see no oil at the top end, you are saying that the cam bearing hole could be plugged? I had these cam bearings installed new and also the crank bearings by a reputable engine shop.

[72RoadRunnerGTX]

On the more than off chance my memory has failed me on this and you have a bearing without the above mentioned grove, I think I would rotate the crank a couple of revolutions a little bit at a time, driving the pump in-between, to see if you can get any oil to pass. There are passages through the camshaft that without the bearing grove would only provide pulses of oil pressure to the top end as the cam rotates. If after continued driving of the oil pump with no oil at the rockers, I would first remove the rocker shafts to observe the passage around the fourth bolt pedestal to confirm no oil flow at the head. No oil at all, I think I would connect a mechanical oil pressure gauge and verify oil pressure. Oil pressure confirmed but no oil at the rockers would indicate a blockage. Most all cam bearings have holes that have to be aligned with passages the block. One of the cam bearings is grooved but I can’t verify at this time it is #4, I may be all wet on that point. #4 cam bearing on a big block Mopar, have at least 3 holes and if installed incorrectly will block off the oil supply to the top end altogether. Hard to imagine an experienced machinist not closely inspecting for this misalignment but I can tell you it has happened many times. The rockers and shafts won’t last long without oil. You may have to remove the cam to verify that bearing is correctly installed.

[mopar71]

Crap!! I took off the rocker arms and can't get oil to the top I have a blockage at the head gasket . The left and right gallery have oil,I removed the oil pressure sender and oil shot out (what a mess).

On the bright side,Id rather find out now before the engine goes back in the car.Any recomendations on good head gaskets?

[72RoadRunnerGTX]

Oil pressure to the heads does not come directly from the oil galleys. Oil to the top end is routed through passages in the camshaft at the #4 journal and bearing. There will be only two points in the rotation of the cam where there will be oil directly routed to the top end, one for each side. As the camshaft rotates this would provide pulses of oil pressure to the rocker shafts in effect regulating a somewhat lower oil pressure within the rocker shafts.
If you have rotated the crank at least two times (remember it takes two revolutions of the crank to get one complete rev of the cam) and have no oil at all at the rocker shafts, it is still more likely to be an incorrectly installed #4 cam bearing. Easiest way would be to have someone slowly turn the crank while you drive the pump, If you are on your own, rotate the position of the crank 10 degrees or so then drive the pump, continue until you have completed two complete revs. You should find two points (one for each side) where you will have full pressure at the rocker pedestals. It would be highly unlikely that the head gasket is missing the holes that allow oil to pass to the heads. Most all head gaskets meant for anything short of a full blown race motor will have two oil passage holes allowing for its use on either side of the motor. Some race heads that are set up to get full oil pressure from external hoses will not have the passage at the deck surface.

[mopar71]

Perfect! thanks, You do need help,my son came over and I had the old camshaft as a guide, I figured out where the hole position was and lo and behold oil shot out on both sides when I slowly turned the crank while my son was working the drill. My only question now is,since I removed the one head can I reuse the head gasket or do I have to install a new one.
Thanks for the photo,thats the photo i was using to follow the oil flow.

actually the right oil gallery does feed the #4 camshaft bearing so it does feed the rocker arms indirectly.

[72RoadRunnerGTX]

I believe the rule of thumb in the trade on that question is “NEVER” reuse a head gasket. I think I would go get another one.

[mopar71]

Thanks Again I will order a new set.