[birkey]

Im really interested in seeing #'s but if anyone could give me a general weight difference between the two rods, and roughly life expectancy of either. Low CR street driven high rpm (7,000-8,000) I was told that a set of new aluminum rods could last up to 100,000 on street

[hcompton]

Yes they will last if setup right. But low compression engine is going to have issues going 8K rpm. That type fo rpm requires vacum pumps and full windage and scraper dry sump oil pans.

Most H beam rods will take that kind of abuse for a street car. Since you wont be running max rpm sep for once in a while. It is cheaper to run the heavy strong stuff than the super light stuff. Both will take the rpm. HP can be different a lot of power will take some planning.

[birkey]

I guess I meant to say not super high.

[birkey]

the aluminum rods won't spin higher? They will spin quicker right?

[vinniekq2]

do not use aluminum rods on the street.no need.a steel rod motor will spin 8k easy

[birkey]

What's a safe CR for aluminum rods

[vinniekq2]

aluminum rods in race engines,nothing to do with CR

[birkey]

They obviously aren't going to handle as much as a 4340 h beam. There has to be a Max cr. I realize no good for street, this is a seperate question.

[vinniekq2]

no CR limit for using aluminum rods