Safe to bore a 383 60 over?

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4fortyDemon

4fortyDemon

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Well, as usual, Murphys law kicks my ***..lol
Engine block is at the machine shop to get tanked, honed and cam bearings r&r'd. Got the call... um, yeah.. you have .008 taper in the bores.... aw ****.
60 over seems too much . Any thoughts ?
 
4fortyDemon said:
Well, as usual, Murphys law kicks my ***..lol
Engine block is at the machine shop to get tanked, honed and cam bearings r&r'd. Got the call... um, yeah.. you have .008 taper in the bores.... aw ****.
60 over seems too much . Any thoughts ?
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Most 383's will go 60 over, a sonic test would be good insurance though.
 
Sonic test sonic test sonic test. I'd do it for you if you were local.
 
4fortyDemon said:
I'd let ya Rusty! And didn't you mention taper at the beginning of my other post?! lol
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I don't even remember your other post. Did I comment on it? I'm surprised I remember my name from one minute to the next.
 
Mopar Engine Manual reference.

IMG_20230912_192434_542.jpg
 
What would one call a safe cylinder wall thickness minimum?
 
Old kimmer says they went.070 over no problem.
But yes have it sonic tested.
 
I'll see what the machine shop says tomorrow. I'll mention to them that I need it sonic tested. Hopefully they do that. It's over an hour and a half from my place.
 
4fortyDemon said:
I'll see what the machine shop says tomorrow. I'll mention to them that I need it sonic tested. Hopefully they do that. It's over an hour and a half from my place.
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Dang, that's a drive. Hopefully it works out for you. What year is your block?
 
Those are usually pretty stout castings. I have a 66 and the machine shop I had do a line bore and hone and the guy said damn, Chrysler used some nice metal in those blocks.
Im now an engine machinist so I agree, compared to a lot of other stuff
 
MOPARMAGA said:
Those are usually pretty stout castings. I have a 66 and the machine shop I had do a line bore and hone and the guy said damn, Chrysler used some nice metal in those blocks.
Im now an engine machinist so I agree, compared to a lot of other stuff
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Agreed! heavy metal for sure.
 
This is bullshit....
1694584180708.png


Thin wall castings?
False. The later blocks have been found to be as thick or thicker than earlier blocks. The later blocks did have less nickel in them and were a little softer but they were still fine. Larry Shephard may have put out some good information but the "thin wall" stuff is wrong.
Why do you think you need to go .060 over? Where are you now? If you're at .030, why not take it .040? My '74 440 block is .040 over. Many 440 blocks have gone .060 without trouble, a 383 should too.
As stated before, a sonic check is the way to go. It will determine the thickness of the cylinders before you go any further.
 
I think you meant to say the pin sits lower on the early pistons. If it sits higher, that will lower the piston in the bore and lower compression.
 
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