Interesting read. Thanks for the link. A sale of $500 to $750 per set right now. Lower than I would have guessed. These over stock sales, where you can save because someone else canceled their order, are often a snake
oil salesman trick and not genuine.
Well on the one hand, I know metallurgy has come a long way over the last 40 years. I also know that one set of data is not enough to state anything for certain.
On the other hand, I do recall books written way back in the day, stating that aluminum rods would not hold up long on the street. They were great for racing where you pull them down and check them frequently, but not for the street. Now this may have been all wrong, but I believe there was something to it. To say "I don't know how the myth got started" might be a little disingenuous and a sales pitch. I have been around long enough to know that people who have a financial interest to sell you something are not always the best source of information.
So have I been passing on an old wives tail that is patently false? Was it once true, but things have changed? Are the manufactures of aluminum rods trying to sell them and conveniently leaving out some things? I do not know.
Assuming they hold up perfectly well, and knowing that the cost is reasonable, why would I want to run aluminum rods? Lighter weight is the only benefit I can think of. The thermal expansion thing is real. Aluminum is 13.1 x 10^-6 verses 7.0 x 10^-6 for steel. A 6.0" aluminum rod a 50 F will be 6.012" at 200 F where a steel rod would be 6.006" at the same temps. It might make sense in a all aluminum engine though.