Just wanting peoples experiences using 5/16 and 3/8 rod bolts. I read 3/8 is recommended and that makes sense. I'm thinking of buying some Chinese rods with the 5/16 for my goal of 325hp e85 only build. Has anyone here seen or heard of a failure that was related to the smaller bolts? In my build I don't plan to rev more than 7200rpm.

Also if I do get Chinese rods where can I source 3/8 rod bolts that will work with say maxpeedingrods?

 

I've never heard of a rod bolt failing on any Miata with aftermarket rods. Just run what it comes with. Nice to have and need to have are two different things.

 

The only failed rod bolts I've heard of are the ones that people forgot to torque properly...

I have 5/16 bolts in mine and it's gone to 360+ at the wheels. I don't rev it past 7500 though, and they're Carrillos, not no-name eBay rods.

--Ian

 

For sure thanks for the info. It seems that the 5/16 are fine for what I plan. As long as they are arp I should be ok.

 

Agreed. My thoughts, if going over 8K, I'd want the stronger bolts, but otherwise the lighter ones are fine.

With Carrilo's 5/16 bolts (which are $$$$ bolts) mine have seen 93XX RPM and are fine.