Factory Rod coating ?June 17 2017 at 10:08 AM
|Pete (Login 427funn)|
I pulled apart a 390 the other day std/std never apart all Ford std bearings C6 motor, I have seen this before but never thought about it, one of the rods is a kind of copper coated and appeared to be done while the rod was bolted together, my ? Is why was this done at the factory,and put in the motor instead of another rod, it may not be copper but is some kind of coating, I know someone here has the answer, thanks
|June 17 2017, 10:45 AM |
Rod big-ends are checked on the line with a "go - no go" gauge.
Back in the day, many rods found oversize or out of round could be saved by copper plating (to build up the surface) and re-honing the big end. They would be sent out in batches for rework, then make it back onto the assembly line. It's fairly common to see the odd copper-color connecting rod in a light duty passenger car engine.
They didn't seem to be doing that anymore when I was in Ford Engineering in the 90's. I even did a stint as a line foreman in Cleveland, putting together the ancient 300 I-6, and I never saw a copper rod. Maybe they figured out that repaired rods weren't worth the warranty risk on a new engine...
Better production methods
|June 18 2017, 5:55 AM |
Most likely this was a result of some changes made in production practices started by the Japanese. If I remember right, it was an American who proposed the idea and followed up by the Japanese industry. I forget who the guy was and what it was called, but essentially it meant better tolerances in production and fewer rejected parts. Better quality control all around and more consistent parts. This started in the 60's I believe, and the American car makers started using the same ideas when Japanese cars were outselling American products. The result was a better more consistent product.
It's called Statistical Process Control (SPC) ...
|June 18 2017, 8:33 AM |
Drs. Deming, Crosby, and Juran were the proponents of Total Quality Management, selling it in Japan. Deming worked with Ford extensively in later years. Some of his principles were never implemented.
In the 1980's, Ford sent me to numerous schools on this. Incidentally, SPC was in practice at Ford since the early 50's. Before computers, calculating Cp/Cpk to determine process capability was done mathematically by hand. The first computer, located in Dearborn, was called Multics. There were telephone cradle modems used to interface in order to perform statistical calculation, t-charting, etc. ... .
Incidently, the size tolerance on the pin bore is .0003", graded in three sizes. With a big end tolerance of .0008", in two grades. Ability to check to that accuracy requires air/electronic gages.
The Con Rod manufacturing process didn't change much until Powdered Metal con rods using laser cracking to separate the cap from the rod.
Copper plating, in addition to addressing dimensional variations, was also used for weight correction. Ref. 7/12/66 Mercury 1966 TSB #51.
And copper plating was used by other
|June 19 2017, 8:13 AM |
manufacturers as well GM etc. Common practice.