SteveBorland said:
Do you have any actual evidence of these rods failing in use?
Gidday All.
very interesting indeed.
Apples must be compared with apples.
The AN product has indeed proved by usage. They are heat treated .
These E-Bay rods claim 90,000 lbs tensile strength. There appears to be a bit of marketing hype in this advertisement.
At 2000lbs to the ton,(short ton) thats roughly 45 ton tensile. at 2240 lbs to the ton, it is even less. My humble opinion is 50 ton yield would be the absolute minimum for this.
A good forging and a billet, made of the same material , and the same heat treatment, should have the same tensile strength.
The big advantage of the forging is the far superior fatigue and strain resistance, probably related to the forgings grain flow.
At a change of cross section of a forging and a billet of the same material, the stress concentrations at this point, would be lesser in the forging. this is because the grain flow of the forging would have lesser internal stress concentrations than the abrupt changes in grain flow neccesary in a billet. grain is very relevant regarding stress concentrations.
So a forging would take the same load with less strain.
my opinion only.
Engineers would explain this far better than me.
This is just an attempt at an explanation
Also for those Ebay rods, no mention is whether the tensile strength quoted is Ultimate or Yield. this can matter very much.
Mr Comstock would be a good authority on this issue. or engineers with experience in these matters.
Jim, any idea of what a good tensile figure for both street and racing rods please?. Yield would probably be better than Ultimate.
Again, designs proven by field testing or usage, are the only choice. This is how the brand names get a good reputation, through successful usage. there are many offerings of this quality.
in summary, a lot more info would be needed to make an informed decision as to whether the Ebay offerings are SAFE or not
Also how does the price of these compare to proven brands?.
When Phil Irving says a con rod can be fabricated by welding, only the foolish would disagree.
best wishes bradley