Having recently taken several materials science and strength of materials courses, my thinking on this is similar to Tim. There is little change in the treated aluminium, though forgings, weldments and possibly machined parts would see a benefit in stress relief.

Here is some supporting documentation from a NASA experiment on cryo treating an unspecified alloy of aircraft grade aluminium. Granted the article stub doesn't give the specific alloy tested but the conclusions confirm what has been said.

I do not know you, but I would be confident guessing that no, you do not like people coming back to you pissed off. I have never run an analysis on a connecting rod, I admit. But I also feel confident guessing that decreasing the radius where the big end blends into the stem decreases the overall strenth, compared to a traditional aluminum rod that has a huge radius there and requires appropriate block clearance.

Wait, did not you just say you did not weaken the part to make it easier to install? Now you are saying you made a compromise...I mean balance...between strength and ease of installation? Which is it?

I do think you came up with a good compromise between strength and user friendliness...just my personal opinion looking at it and guessing, again not personally actually running an analysis.

There's always something stronger. Life's a balancing act.

Ahh ok, so you did compromise on the design. Got it.

OK my bad.

So far 3 of 4 have said they are not running aluminum rods, 2 were adamant about it, and that one guy didn't say he wasn't running steel, just that you won't gain anything switching to steel or ti (I thought ti wasn't allowed in PS, but whatev). These are current prostock engine builders I've talked to since last night. These guys all make engines for cars who consistently qualify, and one of them might hold the current MPH record :dunno:

But like all things Prostock, what works for one team will be completely opposite for another.

Wow! All I wanted to do is show off some pretty rods.


Looks like they can come either way, forged or billet.

I linked Darren to this thread, so He could answer the more technical questions.

Like any other product, there has been R&D, along with many revisions to the rod before the final plan was made.

I am sure Darren has installed a couple sets of these rods in a few engines for dyno runs, and a season or two of real life drag racing.

How many here have run AL rods before?

I do know and understand there is a huge difference between a Miata engine built for road racing, and a 4g63 built for drag racing.

Darren gets what i originally said, this forum aint for BS and talk, give us numbers, analysis sheets, how many hours at 7000rpm they will last with what weight pistons etc etc.

Get to the point with facts please, then we will love you.

Dann

Darren, thanks for hanging out with us. AL rods have always intrigued me a bit.

Could you scale your design down to tolerate less power (say 400whp instead of the 1000++++whp they're probably designed for) and make them significantly lighter? (say 30% lighter than they currently are)

Darren,
I may be misreading, but maybe you can clear this up...

Do you do tensile and fatigue testing on your product? Did you do the same testing to compare forged vs. billet blanks? Or with cryo treating?

Your previous posts make it sound like the testing was irrelevant because you knew billet / cryo "worked".

There's tensile in my fatigues. :naughty:

I hope you have a high young's modulus.

It strikes me that this is a irrelevant discussion, as we will likely never have an option to run these rods.