I was torquing down the second rod bolt on the #1 conecting rod and the head broke off. i was only at about 35ft lbs and it just fell right off. it looks like it was already cracked. has anyone else had this happen to them? it sucks that i need to get new rod bolts and have them put in but i'm glad i found the problem before i ran the engine.

 

Rod bolts should always be replaced during each rebuild. They're cheap when you consider how much damage a broken rod bolt can do. They're designed to stretch when torqued down. The proper way to install them is with a stretch gauge. Chances are they were already stretched when you went to torque them down. How old were they? How much abuse have they seen?

Head bolts should be replaced also but nobody does it. I've seen people rebuild a 30 year old engine (stock rebuild) and reuse the old rusty head bolts.

 

When I rebuilt my engine, one of the threads on the end of the bolt was screwed, so I had to get a couple from my engine shop guy. Replacing connector rod bolts is a good idea, but if you replace both bolts on a rod, you'll probably have to get the part of the rod that goes around the crank reground. I didn't replace all of mine because they looked almost brand new with the exception of the one with messed up threads.

 

If one broke clean off then chances are others are messed up and might fail in a running engine. They always fail at the worst time- high RPMs. There's not much left of a small block when a rod bolt lets go at 6000+ RPMs.

Pull EVERY rod out of that motor and get a shop to replace all the rod bolts and resize the big ends of the rod (or just buy aftermarket rods that have already had this done). I highly recommend upgrading the rod bolts while you're at it. I swear by ARP WaveLoc rod bolts, but there are less expensive choices that are still a lot stronger than stock.

As was said above, you must get the rod's big end resized when you change out the bolts. Not optional.

 

the thing is, i just had it balanced so aftermarket rods are out of the question, and i had the rods resized already. can they do it again without taking to much off?

also, i want to get the arp wave locs because there only $2 more than regular arp bolts. would this present any problems like having to take more off when resizing them, or will they go in like any regular bolts?

i guess from now on i'm going to put new rod bolts in every engine i build.