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Discussion Starter · #1 ·
...Mine does. I have been through at least 6 cams in the big block in my 78 and I think I'm losing another one as we speak. I have heard of a possible solution, and will be trying it next time I have to change the cam. From what I have learned, big blocks are known to get an air pocket in the oil galley that feeds the lifters and causes pre-mature wear on the cam. The solution is to drill a very small hole in the two oil galley plugs that are behind the timing gear on the front of the engine. Below are the pictures of the plugs with the holes in them (the very small dot in the recessed area of the plug). I do not know the exact size of the hole, but you should be able to get the idea from thie pictures.





If anyone has any information on this, whether pro or con, please post it here.

I'll update when I have done this myself.
 

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I've never heard of that Gary. Thats rather odd. Just from lifters being to tight or no pre-lube during install. :neutral:

My buddy has a mid 70's BBC and he's hardly touched it over the years and 2 years at the track.
 

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Discussion Starter · #3 ·
I have had the truck for 20 years and have personally put over 100,000 miles on it. I am always meticulous (sp?) when it comes to engine assembly and pre lubing, maintenance, etc. so I know it's not that. I also know it's not related to cam brand. It has eaten stock, Edelbrock, Comp Cams, Erson and two Mellings cams. I'm trying to decide if I want to try this next time or just go roller. The roller option is really expensive, but would probably solve the problem so that's what I have to weigh.:neutral:

Again, I have not tried this but heard of it through a neighbor that races big blocks. It was one of his blocks that the pictures are of.
 

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Actually Patrick did his Tonawanda in rollers and it didn't seem like a crazy price to me. Ya I figured you for doing a good build up (Lubing cam etc) I was just stating the obvious. If you add up all the cams you could have done rollers a long time ago LOL
 

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If you add up all the cams you could have done rollers a long time ago LOL
You're telling me. I am porting a set of small chamber heads for it right now, so when I do that swap is when I will have to make my decision if I find it is flat.
 

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Discussion Starter · #7 ·

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Discussion Starter · #9 ·
That's what I'm thinking, especially for a truck that is only worth about 3K. Not that I would sell it, my Grandfather bought it brand new in Dec 77. I bought it from him in Feb 88 and my son will start driving in just a couple of years, so he will probably get it. He wants one of the Firebirds, but that probably won't happen 'til after I'm gone (I keep the guns in a safe, so he'll have to try something else).:intello:
 

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A few years ago at a shop in Waxahatchie the owner was talking to me about eating cams in 7.4 motors. I never had a problem with this on any of the B/B's I've owned but he insisted it was a faulty design that 7.4's suffered from. His remedy was to tap the holes like you showed and he also tapped another oil gallery and braised a copper line to the gallery fitting, the copper line was run parralel to the cam and had small holes at all the cam journals that allowed oil to spray on the cam.
I ddint pay alot of attention to the set-up at the time because I never had issues with B/B cams.
 

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What exactly is eating up? Is it the journal or the lobes themselves? If it's in the journal area, then you have an oiling problem. I personally have never heard of or seen the issue, but anytihng can happen. Whats your oil pressure look like? If it's eating the lobes, have the lifter bores checked. If they are out of round, then the lifter won't spin well within the bore, thus resulting in a wiped lobe.

Back to the journal issue, have those bores checked too. A shifted block or mis-alignemtn of the bores will wipe a cam too. Each and every time I build an engine, I have all of the bores and alignments checked. Not sure how old the block is but if it has every overheated the core of the block gets all hosed up, especially the lifter bores. Also, try chamfering the oil passgaes a bit in the block...and use Clevite bearings with the chamferred holes. These tend to work a lot better, especially when using a high volume oil pump.
 
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