Ooooh I love this video! Well, more specifically, videos like this. Videos like this take a widely accepted rule of thumb and put it to the test, to find out if it is really applicable in this particular situation. On the subject of rod bolts, the widely accepted practice of resizing the big end of a connecting rod, whenever upgrading the rod bolts from stock to something like an ARP bolt, come from a pretty simple and logical principle. The idea is that if you take a stock rod bolt out, and replace it with one that can clamp down “tighter”, it will distort the rod slightly and then lead to bearing failure. In order to avoid this, resizing of the rod after the ARP bolt install is a good idea. Makes sense right? Well, sorta.
Here’s the thing. It kinda depends. At least in my mind it does. Because connecting rods are different, I suppose I understand the theory for some of them but probably not all of them. A connecting rod who’s big end is located by the rod bolt may in fact be able to “move” more under increased torque. But what about connecting rods that are located by a hollow dowel? Or by fracture? These types are mated in a way that makes movement far less likely and therefore harder to accomplish by tightening it more.
And all of this relies on the ARP fastener actually being tighter. Do all high performance fasteners have to be installed with a base torque number that is higher? Or do some fasteners have higher strength that keeps them from stretching compared to the stock fastener? Or is it a combination of both? All good questions, and the answers definitely help with the overall question posed in the video.
Watch the video and let us know what you think. Resize or not?
Also, he gets Bonus points for wearing an OG BANGshift shirt by the way.
Wow, thanks for posting my video guys! It’s an honour to be featured on my favourite automotive site.
Great video! I have wondered about this for years and always go to what I was taught. This proves that the information is correct.