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454 rocker oiling problem.


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I recently rebuilt my 454 and the machine shop that cleaned the block drilled a 1/16" hole in the 2 front oil galley plugs. They said this helps to relieve air pressure in the oil galleys and gets the valve train oiled quicker on initial start up. It also helps to oil the timing chain.

 

I used a Comp 270H Magnum hyd roller kit and cleaned all parts before installation. I've ran the motor several times on the stand, but only for short (20-40 second) periods, since I don't have a radiator connected. I primed it with an air ratchet before starting and it took a long time (10-15 minutes) to get the 10w-30 up to the rockers with about 30 psi of oil pressure. Of course the rear rockers flowed first and the oil moved forward, and the passenger side got oil to all of the rockers before the driver side.

 

My problem is that the #1 exhaust rocker gets very little oil. #1 intake is good, but naturally not as good as those further back. I checked for obstructions in the push rod and rocker oil hole. This evening, I pulled the intake and checked the lifter by disassembling it and it's fine. I swapped that pair with the 2 from #7 cylinder and also spun the primer rod with the #1 lifters out and there looks to be good flow in the galley. I also put the #1 intake lifter in and spun the rod and saw good oil flow in the ex. lifter bore. Changing the lifters didn't help. I get very little oil from the #1 ex. push rod. I have a new MSD distributor and Edelbrock intake. I've checked to make sure the oil ring in the distributor lines up with the oil galley holes. I'm wondering if the 1/16" holes in the front galley plugs are the problem. I called the machine shop today and they said holes that small won't cause this. If anyone here has advice, I'd love to get it. Thanks!

 

Dan

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I can't speak for your lack of oil, but I can tell you that my 454 had the holes in the oil galley plugs - and that was rebuilt back in 1988. My 502 had them, and my builder friend took them out thinking they were drilled out by somebody. After some reading, the drilled plugs keep the back of the cam sprocket lubed, so it doesn't eventually eat into the block. I had to take my 502 apart and reinstall the correct galley plugs (PN 11609914 Front Oil Galley Plug, .0300" squirter hole to lubricate the timing chain - per GM).

 

That said, 1/16 sounds on the large side (.0625"). I remember the new ones I mentioned above being a smaller size than the originals. I have them sitting on a shelf in the garage - I can measure them with a drill bit at lunch if that helps.

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I checked the holes of the galley plugs and here's what I found:

 

Old 502 plugs: Approx 1/16 or .0625"

 

Old 454 plugs: Approx .030"

 

New GM plugs (11609914): .030"

 

Not sayin that changing the plugs would solve anything, just noting you are on the larger size.

 

If they were too big, I would suspect all the rockers would be low on oil.

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Out of left field here but were the cam bearings replaced? If yes, could one not be lined up with the oil hole? Never had a BB apart, may not even relate.

Bruce

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Bruce, big block cam bearings have the hole at 6 o'clock and have nothing to do with supplying oil to the lifter galley. the 65 and 66 396 and the 66 427 had to have a groove in the rear cam journal to supply oil to the lifter galleys. afer that the blocks were grooved behind the rear cam bearing shell to supply that oil.

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I'm in the middle of my own 454 rebuild problems, and don't know if my oil galley plugs were drilled. I didn't notice and the machine shop didn't say. What I can say is oil flowed pretty easy out of my rocker arms when I used a 1/2" drill and my ground off gear old distributor. Less than 60 seconds I'd say and it was oozing out everywhere. Not sure what the oil pressure was as it's mostly a one man team.

 

Have you watched it when it was running, or just with the ratchet? Does it tick when you run it?

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all his oil is coming from the oil galley that supplies oil to the hyd lifters, at the end of those galleys is a plug. i like to think of those plugs as a faucet. the more you open that faucet the less oil will be pumped up to the rockers through the push rods from the lifters. least path of resistance

now keep in mind those lifters need to rotate in order to fill with oil and supply lube through the push rods

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hyd rollers don't spin like flat tappets, I don't buy needing holes in the plugs, there is enough clearance between the lifters are there bore to let air escape or be pushed threw the lifter and out the push rod

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Gm started drilling that hole in the front lifter oil galley plugs to relieve air in the galleys after the engine has been sitting for an extended period. It was said it prevented lifers from ticking. oiling the timing chain was supposedly an added benefit.

I never run the plugs with the oil holes. The cam bearing sends plenty of oil to the thrust surface of the timing gear.

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I pulled the timing cover today and removed the plugs and replaced them with some that are drilled .030".

 

A couple months ago, when I got the block back from the machine shop, I noticed the holes in the plugs. I stuck a wire into each and one wasn't even drilled completely through. I called the shop and asked why they had done that and he said both were drilled and told me the reason. I told him I'm sure they meant to, but they didn't quite make it through on one. He said to just finish drilling it with a 1/16" (.0625) bit and I'd be set. I did and reinstalled it. Today I found why the passenger side was oiling better than the other. The hole in that plug was less than .0625 and when looking closely I could tell with just the eyeballs. I called the shop and explained what I found and reminded him he was the one that said to use the 1/16 bit. He gave me the 2 new .030 drilled plugs and a set of Edelbrock intake gaskets and the rest of the gaskets I need to get it back together.

 

I primed it this evening and it only took about a minute to get the oil to all of the rockers this time. I think I'm going to stake the edge of the holes to almost close them completely because I had the timing cover off this time and I still get alot more oil through the plugs than I think it should have, even though the rockers are all oiling now. Problem solved.

 

I think the air escapes out the top of the push rod just fine.

 

Thanks to all of you for helping. smile

 

Dan

 

 

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That is certainly good info for anyone rebuilding a big block-glad you found the problem and would be nice if everyone doing a similar rebuild sees this first-amazing how the devil is truly in the details-as massive a machine the big block is, just a few mils difference in a couple of oil holes makes a nite and day difference!!

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