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I just read on here about the oil galley plugs needing to have a hole in them to supposedly oil the distributor shaft and timing chain.
Now that I'm finding out about this, it makes me ask the question, how imperative is this.
I'm at the machine shop now asking if they remember pulling any galley plugs out of the engine with any holes in them, and if they remember any holes in the new galley plugs.
They're not recalling.
The engine is completely together minus the distributor and carburetor.
I've tried sticking a mirror in the distributor hole to see, with no luck.
I have read about knocking out the soft plug to check, which I do not want to do just to check.
So my question is, this block is a 69 350 block, and if this engine ran from 69 on with no holes in the galley plugs,
Why is it all of a sudden imperative to have them now.
Did these olds engines come from the factory with the holes in the galley plugs?
The last 2 blocks I had machined came back with no hole plug at rear and lost plugs on the other. You cant trust shops so I always try and pull them myself. Mondello used to say you can weld up the hole in the front plug to get a little more oil pressure. I don't know what the end result would be with the rear plug having no hole but I would think you want oil spraying on dist and cam gear. I would try and see what is there to be sure and its no biggie to pull the cap and install a new one.
Put oil in the engine, leave the distributor out, spin the oil pump and see if oil squirts into the area. If not, you will need to put in the correct plug or drill the existing one. The oil from this plug is required so that the distributor gear lasts longer than a few weeks.
The front plug oils granny's timing chain because she never turns the engine faster than 2000 rpm. If you run through the gears periodically, you get enough splash lube to keep the chain happy. In any case, it's simple to put the correct plug in if you want.
I called Mondello earlier, and they're telling me that Oldsmobile engine did in fact come from the factory with the front bolt with a hole in it to oil the timing chain.
They said olds engines Did Not come with the plug in the back with a hole in it, I was told this is something they did to help the distributor gear from prematurely wearing.
So after tearing the engine back & checking it out, the front plug did indeed have a hole in it,
The rear plug did not, and this is the way the kit came, I have checked on summit and their soft plug/oil galley plug kit.
The rear oil galley plug non of them has a hole in it,
I've only seen it on mondello' website today,
So what I did was knock out the soft plug and remove the galley plug, center punched it and drilled a 1/16th hole through it, chamfered it up a lil, and put it back in the block,
Now both plugs have their hole through them, only cost me time, and about 30.00 in gaskets,
It's back together again, now I can proceed with finishing it up and getting it on the run stand for break in before the week is out.
I'm not gonna blame the machine shop for this, the plug in the rear that came out of the engine originally didn't have a hole in it, so they put it back like it was stock.
I have every reason to believe my 65 425 was never apart. I found all 3 plugs had a hole in them and that is how it went back together. It is confirmed by my 65 CSM .
This was my first Olds rebuild. I always assemble my own engines, removing all plugs before sending out block.
I just don't understand the comment about Mondello saying the factory did not put a plug with the hole in the rear. I've heard others say there was only one drilled in the front. Maybe later on the factory only determined one was needed in the front.
Just read the Chassis Service Manual, which very clearly describes the use of plugs with weep holes in both the left rear oil gallery plug ("...for distributor lubrication...") and the right front oil gallery plug ("...for the timing chain and gears."). I just happen to have the 1968 CSM at arm's reach, and in that version it is on page 6B-25.
I called Mondello earlier, and they're telling me that Oldsmobile engine did in fact come from the factory with the front bolt with a hole in it to oil the timing chain.
They said olds engines Did Not come with the plug in the back with a hole in it, I was told this is something they did to help the distributor gear from prematurely wearing.
Which Mondello, California or Kentucky?
California are idiots, as demonstrated here.
I checked the CSMs up to 1975, all contain the same picture and text regarding the holes in the plug fore and aft:
Actually, this paragraph is misleading as it implies splash oiling from the cam bearing. The later paragraph I cited above specifically calls out the plug with the hole.
Also interesting is that the drawing correctly calls them oil "galleries" but the paragraph I cited incorrectly calls them "galleys", all within a few pages.
It's was the California mondello,
Not disputing anything you guys say, I was just told this today when asking how imperative it was to have the galley plug, and if it came from the factory like this.
His exact answer was what I gave you.
In any rate, I have fixed it and hopefully I shouldn't have any suprises now,
Fingers crossed,
Best I found out about this now, rather than later when the engine was in the car.
Thank you all very much for your knowledge.
I'll report back, when she's running,
Possibly post up a video too.
Actually, this paragraph is misleading as it implies splash oiling from the cam bearing. The later paragraph I cited above specifically calls out the plug with the hole.
Yeah, I just grabbed the first descriptive paragraph I saw, as I was hurrying to get through the rest of the posts, but you're right: the other paragraph is better.
And, 85 Cutty, you seem to be missing my point: The people at the Mondello place in California don't know anything. They are poseurs. It is very unwise to rely on them for any sort of information (or parts, or machine work) at all, because they will randomly provide you with BS.
Search for references to them on these boards.
In the 65 CMS the plugs are described on page 3-61 as having holes in all three as my engine did. Maybe later the gurus determined only one front plug with weep hole was needed.
... what I did was knock out the soft plug and remove the galley plug, center punched it and drilled a 1/16th hole through it, chamfered it up a lil, and put it back in the block
This stuck in the back of my head.
1/16" = 0.0625"
The difference between 0.040" and 0.0625" may not seem like much, but the areas of those two holes are 0.81 and 2.0 sq.mm respectively, which is a fairly large difference.
Further, since flow through a round tube is a fourth power function with regard to radius, with pressure and viscosity otherwise equal, the potential flow difference is two orders of magnitude, or about a hundred times (engineers, please do check me on this).
I'd go back in there and install a plug with a smaller hole.
Damnit!!
Your right,
I redid the math, and with a 1/16th drill bit, the hole is roughly .063 instead of .040.
So what's my worse case scenario on this,
Am I goin to have like 10psi oil pressure at idle now?
I guess I'll tear into again and just order the plug from mondello's.
It was hard enough to drill with the 1/16th without breaking the bit,
I could only imagine a paper thin bit.
Assuming same fluid velocity, I'm getting 3x the cross sectional area, thus 3x the flow, via q=AV. I would think the biggest problem would not be a pressure drop, or running out of oil, but flooding the timing chain and distributor cavities, for lack of a better term.
I ran into this problem about 20 years ago. I had a engine builder rebuild my 455, and left out the rear oil gallery plug completely. There was no oil pressure and burned out the top end during break in. I learned quickly don't use a Cheby or Ford guy for that matter to rebuild an Olds. An article I read in Car craft magazine not long after stated the same for this very issue and others. As others have mentioned a .040 hole in the plug is called for.
...
It was hard enough to drill with the 1/16th without breaking the bit,
I could only imagine a paper thin bit.
Yes. An .030 bit is tiny. It'll bend/snap if you breathe on it wrong.
The trick is to not try to drill all the way through the plug with the tiny bit. Drill the .030-.040 hole from the front to ~ 1-2mm depth. Then carefully drill an 1/8" hole from the back until you're almost to the little hole. Finish up with a little more .030 drilling & cleanup.
I don't have a drill press. I drilled the .030 using an old Dewalt 3/8" corded drill & cheap HF bit(s). This drill seemed to have the most precision of my drills. I mounted the plug in a scrap of wood on my bench. Then, resting on my elbows, held the drill above it allowing only very, very slight pressure on the bit. (Human drill press!). Went very slow - 15+ mins to get to 1+ mm. Hand twist drilled the last part.
To further this discussion and couriosity, I checked a 455 block that has not been tore apart before and hole in front plug but no hole in the back plug.
See pictures. This appear to be a 68 block. C head motor, J intake. Is there any other blocks that we can document where they were these plugs did not have holes from the factory?
I was thinking I read somewhere that the reason for the extra lubrication on the distributor was because of the gear being like screw "sorry I can't think of the correct term " it pulls down on the shaft causing wear which makes the timing erratic. Because of the shaft being able to move up and down and the twist of the gear. Been a long though.
Railguy
Didn't the factory plugs have a square hole and not a hex hole? If you see a hex plug it is not factory as I recall. I remember this because I made a tool out of a bolt to fit the square plug as it was bigger than a 1/4 drive and smaller than a 3/8th drive.
1) So is it indeed a fact that "all" rear plugs had square indents and holes?
2) Or did this change somewhere during many years 455s were built? Or did the engine shop just put whatever they had in?
Don't get me wrong, I believe that the .040 hole should be in there and that it will be in my engine that is being rebuilt.
I am just courios, if we can use the word "all". It seems like there is enough instances: 1 Confusing wording in the assembly manual. (It seems that if purging was the purpose, that the back lifters and cam bearings would suffer as those holes would clog. ) 2 Some say their block didn't have one to begin with.
On the block I have, I cannot say for certain it has never been apart, but there is no indication that it has.
I suppose I could look at the cam and see if they are factory casting numbers, as more evidence.
Again just courious if "all" is applicable or if mass production created variances, or if there was an engineering change.
April 18th, 2016, 07:05 AM
