Well, I just broke my 360 block. Terminal?

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fshd4it

fshd4it

Squid inc
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Went to install the oil galley plug that goes above the rear main cap, 1/3 of the way up toward the oil psi sender. Couldn't find what size it was, got in a rush 'cause I'm going back to work tomorrow, so I checked the holes at the front of the block (under the cam plate) and found they measured the same. Assuming they used the same plugs, I started to drive a 19/32 plug in the hole. Halfway into the cap surface, I blew the hole out into the bearing saddle. If the chunks come out, the back 1/4-1/3 of the rear bearing has no backing on that corner. Started throwing ****, took some pictures, and walked away. The felt pen mark is about at the back edge of the bearing.
Probably shouldn't run it without full support under the bearing, could it be welded and remachined? Of course, I waited until the block was completely done before doing this...hoping it's not a $1k mistake.

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Ben Drinkin said:
That sux!!! No idea if it's fixable, but I feel for you...
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Well, it's like my dad always said, "Experience is what you get when you didn't get what you wanted". Also something about the learning curve being really expensive...
 
Most people don't realize that there is near zero pressure on a bearing in that area.
They are made slightly tapered thinner towards the ends, and is why worn ones look like this.
Your choice of course, but I wouldn't have a problem dressing that up and running it.

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That was my first thought after pondering it over a cup of coffee. Or 4. I figure I can't make it any worse than it already is. I'm off to the parts house to get a smaller plug and see how that fits.
 
That doesn't excite me at all honestly..... At the very least I would think the cradle area will need aligning after the determined repair is decided. If it happened to me and surely it could I would probably take it to my machine shop and we discuss what can be done....

If my machine shop has any doubt about a repair the block would not be used for my build..... Too many other things that can happen from something like that.

Luckily this is not some type of crazy aftermarket block. Then you would have a whole new set of problems.....

JW
 
I looked at the plug I tried to drive in, and it's deformed. Wasn't me, my brass drift was down in the plug. There's a noticeable bump at the top of the picture. I'm guessing I clocked it just right to point into the bearing saddle, not so sure I had the wrong size so I'm going to try a 9/16 and see. Even if the block goes back to the shop, the plug can stay in as far as I care.
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Or, now that I've had time to think about it, maybe the plug deformed when the wall blew out. Dunno.
 
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If the pieces come out I would think it could still be bushed in the worse case scenario. Stepped, similar to a drill guide bushing maybe?
 
that is a pressurized oil passage. I think if you just grind the area without welding there is going to be a small void, and it will be asking for lower oil pressure and a rear main seal leak. a skilled welder could weld it. why guess at plug size? can someone please measure the hole? I do not have a block handy
 
Marcohotrod said:
that is a pressurized oil passage. I think if you just grind the area without welding there is going to be a small void, and it will be asking for lower oil pressure and a rear main seal leak. a skilled welder could weld it. why guess at plug size? can someone please measure the hole? I do not have a block handy
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It's going to get plugged anyway, so as long as the plug goes deeper than the cracked part it'll be golden.
 
wrong, the plug separates the oil in from the pump then thru main cap going out to filter from the oil coming back in from the filter
 
Marcohotrod said:
wrong, the plug separates the oil in from the pump then thru main cap going out to filter from the oil coming back in from the filter
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Maybe wrong, isn't it just a drill access for the verticle oil galley?
I thought it was.
Either way it can be easily fixed.

That is the block we are looking at and not the cap, but I understand what you are saying.
The rear main bearing half being crushed in there will keep that blocked off anyway.
I would just lay a deep socket in there and tap that raised part back down flat and put it together.
 
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Marcohotrod said:
that is a pressurized oil passage. I think if you just grind the area without welding there is going to be a small void, and it will be asking for lower oil pressure and a rear main seal leak. a skilled welder could weld it. why guess at plug size? can someone please measure the hole? I do not have a block handy
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Ah yes. It didn't occur to me until I thought about it, but you're right. That is the pressure side coming out of the pump (after passing through the cap). A hole there is the last thing I want, looks like it's off to the weld shop we go.
 
Why not consult a factory service manual for the correct size plug, instead of playing guessing games and making another mistake?
 
RustyRatRod said:
Why not consult a factory service manual for the correct size plug, instead of playing guessing games and making another mistake?
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My '74 service manual has no info about oil galley plugs. No locations, dimensions, or references at all. But what I know now is that the bore is stepped, it's a smaller diameter at the top where the plug goes. So it does not have to be driven all the way into the bore, I just put it in and drove it the last 3/4". The plug size is 9/16".
 
fshd4it said:
My '74 service manual has no info about oil galley plugs. No locations, dimensions, or references at all. But what I know now is that the bore is stepped, it's a smaller diameter at the top where the plug goes. So it does not have to be driven all the way into the bore, I just put it in and drove it the last 3/4". The plug size is 9/16".
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Well, I am breaking ranks from the rest. If that was my block, I would want that area repaired the best way possible. That's not an area that you want stress cracks forming in. JMO.
 
I'm on the fence here. I'm not a fan of anything being weird in the mains or oil feed passages. If this was going into a soccar mom's car maybe, but if it's going to be abused the potential exists for a bigger issue after it's assembled. But, the act of fixing it will cost s boatload to weld it and remachine the areas affected. I've had to remachine a second 340 block after a crack missed in magnafluxing was found. 360s are cheaper to find...lol.
 
This is not a big deal. Drive a 9/16" plug in there, dress bulged out area down by hand or die grinder and move on. J.Rob
 
Don't like any cracks in blocks. Too bad your so far away, I have a 360 block I'd just give you.
 
Since this is a very thin walled area to begin with, and we don't hear ever about cracks in this area, then I think it is safe to assume that there is little to no stress in this area normally, and will not be prone to cracks. If 'twer me, I'd:
- torque the cap in place and measure the bore dimension carefully
- braze it up a bit at a time and dress it down
- re-torque and re-measure carefully
 
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