Why is one 340 connecting rod bronze color?

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The information supplied in post #35 has it's place in the industry, what that is all referring to is for use in the motorcycle or snowmobile engine manufacturing, where "surface hardness of Rockwell C of 60-63" needs to be achieved for use with "roller surface" type bearings.
What's going on here is simply put in post #25 a last attempt to be able to use a rod before it's turfed.

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Well I dropped off four pistons and 12 rods at the engine shop Friday.

The four good pistons I have were on four recently reconditioned rods ( one night of racing) but I figured it sure wouldn't hurt to have those four rods rechecked for size and straightness after being involved in a 7,000 rpm explosion! Hopefully we'll have eight good rods in a few weeks.

Gary, the shop owner, didn't blink an eye at the three copper rods in the box... seen them before.

The pistons that were in this 383 are, as I suspected, made by Ross so the shop is having four replacements made. I have one more with a little 'nick' that I will keep for an emergency spare.

One step closer...
 
66Dvert, where is the Looney tunes industry music while reading this?

Reminds me too much of my chicken days , so I skipped it(but my grandkids still watch stuff like that on youtube constantly)
 
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View attachment 1715107441 The information supplied in post #35 has it's place in the industry, what that is all referring to is for use in the motorcycle or snowmobile engine manufacturing, where "surface hardness of Rockwell C of 60-63" needs to be achieved for use with "roller surface" type bearings.
What's going on here is simply put in post #25 a last attempt to be able to use a rod before it's turfed.

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If that is a 1970 -75 440(RB) or 383-400(B) rod then chances are I ran it. I was working 14hour days 320 days a year back then. Forced vacation during changeovers to a new year car and some holidays off but mostly 7 days@ 14hours.(talk about a zombie) A good friend of mine worked the /6 rod line even longer and lots more hours until they cut the line and quit producing /6's
 
I need one of these mysterious copper rods for the garage wall..
 
Cracked open my 340 for a rebuild today 6 of the 8 rod were copper plated. I guess my only question is can they be rebuilt and reused?
 
I'll be doing a set of 318 rods tomorrow, and 3 of them have some copper filling on them. I'll post before and after pictures so we can see the outcome.
 
A little late, but here it is. JoeSBP I've got a freshly plucked one out of a 78' 350, PM me so I can get you a birthday present. #3 is for Joe.
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Wrong. Copper is way soft and would not hold up to the beating of a rod journal or piston pin can dish out. Copper is the material but it was done merely for corrosion resistance. I have seen engines with all of the rods copper coloured. The bean counters surely put a stop to it. J.Rob
Lmfao
 
Copper was used as protection against the flames when they rods were heat treated. You will see the same on many camshafts. Most were washed in a solution that removed the copper... some did not. No rhyme or reason...

There has been a lot of speculation and misinformation about this for years. Do some research on flame heat treating and you will see the same info.

20 years ago I often loaded GM engine parts that had been heat treated from a shop in in MI and I hauled them to the North Tonawanda plant in NY. I watched copper coated cranks enter the heat treat furnace and saw others go to the wash tank. Lunati had their cranks done there and I'd see racks of BBC cranks destined for heat treat.

It has zero to do with repairing undersize or mis machined parts.
 
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