Help me ease my mind.......Rod Knock???

Oldiron440

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I've got 318 rods in my 367, and it's been blasting to 7000 since 1999. I can't say 318 rods are weak; but mine did get ARP bolts.


And not only did I sleep at a holiday inn last night I caught a world record catfish before six am and the new world record catfish at 9 am, all on 2lb test line. All this with one bad eye.

And all this with the wallace race calculators.

And I can't believe all the beautiful 20 year old women who are constantly trying to hookup with me.
 

BudW

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I have an opinion to rod bolt failure (any rod bolt) – but have absolutely no proof (so this is only a working theory):
I suspect when the rod bearing has worn (or failed) to the point the bearing is making a knocking noise - the hammering of the rod hitting the crankshaft twice a revolution, fatigues the bolt to failure, or if noting else, causes the nut(s) to loosen – which compounds the hammering effect.
I have seen the loose rod cap nuts (or broken studs), on rods with very little (or no) rod bearing remaining (ie: a catastrophic failure). A rod bearing will make noise well before that point, which makes me wonder about things.

On a different note, if you have a sudden stop of engine oil flow (ie: stopped up oil pickup tube, zip/zero/nada oil inside engine, striped or broken oil pump driveshaft, stuck fully open oil pressure release valve, etc.) then I have seen rod bearing fastener failure occur very quickly –for without any lubrication any engine will fail soon.


Also, my experience has shown when you have a bearing failure, generally (not always) and with the engine oil pan is off, you can see discoloration of the effected rod bearing caps (which happens before rod cap fastener failure) from excessive heat.
I had a few pictures of the rod cap discoloration to show, but it appears those photos don’t want to be found. This is a (poor) picture I found on the internet:
iu2ML0O289.jpg

I've seen the rods change a wide range of colors (dark black/blue to almost white). Almost always a noticeably different color than rest of the connecting rods are. This rod cap didn't change color that much - but is still showing signs of overheat.

BudW
 

AJ/FormS

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Late318 rods are same casting numbers as 340s and same as early 360s; namely 3418645.
The only differences are bushed or not.
340s went 6500 with their 719gram slugs,and only stopping there cuz the valves were floating.
My KB107s are only 502grams, so why would anyone think they cannot go 6500 and more.
In 2004, my car was timed at 93mph in third gear with 27" tires. The trans ratios were 3.09-2.41-1.92-1.50-1.40-1.00-.78 od and in the rear were 4.30s.
Yeah you could argue that I was in direct at 4968, but yaknow, I didn't put this combo together to idle thru the traps. Those 4.30s were back there, cuz I was hoping to top out in second over.... But I can tell you this; I was in second-over (1.50 ratio) hoping to make the traps. But at 89 mph/7200rpm, I could clearly see I wasn't gonna make it, so BAM! , I pushed and squeezed, and got me another 480 rpm. That's the way; un-huh, uh-huh. I had underestimated the old 367.
The math says rpm was 6955@93mph, and tach was right there. Actually, the tach was "right there" pretty much the whole way............
My rods have been happily swinging on the 3.58 since 1999.
If yours blows up at sub-7000, maybe your engine just doesn't get enough practice. I can't speak to your luck; maybe you shouldda prayed over it.
Yuk it up
 

Oldiron440

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Late318 rods are same casting numbers as 340s and same as early 360s; namely 3418645.
The only differences are bushed or not.
340s went 6500 with their 719gram slugs,and only stopping there cuz the valves were floating.
My KB107s are only 502grams, so why would anyone think they cannot go 6500 and more.
In 2004, my car was timed at 93mph in third gear with 27" tires. The trans ratios were 3.09-2.41-1.92-1.50-1.40-1.00-.78 od and in the rear were 4.30s.
Yeah you could argue that I was in direct at 4968, but yaknow, I didn't put this combo together to idle thru the traps. Those 4.30s were back there, cuz I was hoping to top out in second over.... But I can tell you this; I was in second-over (1.50 ratio) hoping to make the traps. But at 89 mph/7200rpm, I could clearly see I wasn't gonna make it, so BAM! , I pushed and squeezed, and got me another 480 rpm. That's the way; un-huh, uh-huh. I had underestimated the old 367.
The math says rpm was 6955@93mph, and tach was right there. Actually, the tach was "right there" pretty much the whole way............
My rods have been happily swinging on the 3.58 since 1999.
If yours blows up at sub-7000, maybe your engine just doesn't get enough practice. I can't speak to your luck; maybe you shouldda prayed over it.
Yuk it up
This makes a lot of sense. :rolleyes:

NOT
 
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Ele115

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Maybe it's just me but I really haven't seen that many rod bolt or rod cap failures. I haven't been around as many small blocks as some of you though, but I'm older so maybe I've been around a lot more that never come apart.
 
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