273 block question

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76440NY_nTX

C-Body Road Warrior
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Aug 30, 2010
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Houston, TX
Hey guys! I started going through the back log of projects and am getting around to my 273 build. I picked up the block from getting it cleaned and checked for cracks and didn't notice what appears to be a huge nick out of the drivers' side deck near cylinder #3. I talked to the machinist about it and he looked at some pics and said I brought it in that way; okay, cause I looked at some pics I took before taking it in and agreed. He said he'd never seen anything like it, but that he wasn't a Chrysler/Dodge guy. :/

I was inspecting further and it almost feels like the block was cast this way, but my gut is telling me differently. The troubling part is it feels like a good chunk of the block near the #3 cylinder was impacted. I wanted to see if anyone else has seen this in their blocks. If the block is toast I'm wondering why kind of trauma caused this and am kind of impressed that it cleaved so well.... Pics 1 shows the deck issue, Pics #2 & #3 tried to show the depression, and pic#4 is the casting number in case anyone was curious. If the block is toast, I'll be sad, but that would free me up to move onto my 383 :) Always the optimist!

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It obviously has some miles on it but it looks like the deck surface is good where the fire ring of the head gasket seals. Just my opinion, I wouldn't use it unless you have no other choice.
 
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toolmanmike said:
It obviously has some miles on it but it looks like the deck surface is good where the fire ring of the head gasket seals. Just my opinion, I wouldn't use it unless you have no other choice.
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Interesting, I didn't even think of that. Yes the car, and I'm sure everything in it, had seen some better days. I don't really need it and can probably get a fresher block from someone else on the board. I'll just stow it out of sight for a few weeks and then take it to one of the local machine schools and let them practice on it some. Appreciate the opine.
 
I'm surprised your shop didn't notice that before they started working on it and charging you for it.
 
Sedanman said:
I'm surprised your shop didn't notice that before they started working on it and charging you for it.
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Yeah, there were a few times it could have been caught. It's one of those things that goes in the notes when taking in an engine and it just didn't register until after the fact . The guy gave me a good deal on cleaning and checking the blocks and storing them for free for me so I'm not too distraught. This one has gotten off to a rough start; one of the heads had a broken rocker arm boss on it so I was already down a head. :/
 
I believe where your finger is, is normal....
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...but the rough part (looks like an airplane wing),above and to the left looks like a chip.

I'd get a pic of my engine block, but its in the car with the ex.manifold blocking the view.

Here's a pic from the net...

Engine014.jpg


Could it be the early 273 castings had this to clear the steering box in the early, narrow engine compartments?
 
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I would bet it would work just fine if its a stock build. I would not hotrod it, it has way too much core shift. It defiantly needs ultrasonic tested.
 
Yup... supposed to be there to clear a power steering box in the early A. That missing section is no big deal.
 
I would still ultrasonic test it especially if you bore it. Look at the freeze plug holes, they are at least 1/8" to the rear. That means the cyl bores are 1/8" to the rear, I bet the cyl bores are 0.080 - 0.100 thicker in the front than the rear.
 
I have worked at a foundry for 10 years, and am hearing too much incorrect casting speculation. the core is used to make the inside of the block hollow, where the water goes. if some sand broke off the core, the block would not hold as much water, but you probably would not see it. I do not see any core shift, that would be the hollow inside where the water goes being offcenter, detected by sonic testing wall thicknesses . with the small bores of the 273, looks like mopar may have made it that way for more steering box clearance. the core plug holes may have just been machined offcenter, cuz it is not critical- does not necessarily mean the bores are off
 
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When the bare block is ready for machining the first holes that are drilled are the 2 on the left of the bottom of the block, (see pic) this is were the block is lined up on the machine. At this point all the holes are drilled, core plugs, lifter bores, cyl bores, there for every thing is on that center line. If they changed machines for every section that got machined it would take forever. If the freeze plug holes are way off then so are the lifter bores, and the cylinder bores.

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back in the 1960s I don't think they had 1 machine that could machine a block 100%. and that old 273 block pictured managed to run fine for decades
 
How do you think they did it? Marcohotrod has no idea, my dad worked for Chrysler twinsburg from 57 till 92 i was up there many times as a kid, although it was a stamping plant the machines were gigantic. So Marcohotrod here is a picture of that 273 getting bored.

machining.jpg
 
nice picture. show us 1 of that same machine drilling lifter galleries. that is why the first thing machined was the 2 indexing holes that U circled in your first pic. the block went down a machining line, from machine a to b to c
 
You are correct, but back to the question at hand? Do the 2 holes on the bottom of the block line the block up for all the machine work, Yes they do. So if the freeze plug holes are off then so is everything else.
 
brian6pac said:
You are correct, but back to the question at hand? Do the 2 holes on the bottom of the block line the block up for all the machine work, Yes they do. So if the freeze plug holes are off then so is everything else.
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If they were off buy too much it would cause issues. There is side clearance for the rods on the pins and the core plugs are a non issue if off a small bit. Core shift has always been a issue. Sonic check is the smart thing to do.
 
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