What is highest safe RPM for stock 455 piston rods ?

Just to add....reason is rod bolts are meant to stretch. IMO one use only. I have two 70 455 that have never been apart and have thousands of runs between the two. I don't worry about those bolts since motors they have never been apart but reuse is no-no.....unless just for cruising....even then I'd go new ARP.

Also, I bet lots of times if a rod bolt breaks and takes out the rod and the rod gets blamed. I have seen bent Buick rods from bolts breaking more often.

 

Hell I'm a backyard mechanic an I replaced rod with ARP bolts an studs for crank. You wouldn't reuse your stock head bolts that has been on there 25 to 30 years an stretched all to hell would you? Do it right an replace them all, even manifold. You can get the whole kit too. Besides if they are well used they don't torque right an some can even come loose so use some threadlocker on them rod bolts.

 

Virtually ALL bolts are meant to stretch.

"One use only" would mean that you'd have to throw the bolts away after the rods are resized. As soon as you unscrewed them from the rod-resizing process, they'd be used-up. You'd never be able to put them around a crankshaft.

Bolts are reusable indefinitely, unless they're permanently stretched, or have surface defects from corrosion, or the threads have worn-out. If they've got metal fatigue, they probably weren't tightened enough.

I'm not saying that ARP replacements aren't better than OEM.

 

Don't forget the "torque to yield" bolts, those are one tighten wonders and they're done, but usually those are for head bolts where stretch can't be measured.



Derek

 

Looking back at this thread. What is the correct answer here?

 

5500 RPM is safe for stock rod bolts, and for you probably the right RPM to build around in general...but if you're into that motor I'd still replace them, which presents its own difficulty but Jim can expand on that...

 

Your playing with Fire if your tune is not dead on , or maybe even a tad rich and your spinning a cast piston motor that's making more then 450 hp above 5500 rpm!
Be ready with a phone number for a towing service!

 

Thanks guys I meant are the 12 point nuts stock?

 

Aftermarket

 

Oh ok, thanks guys. I actually referenced JW's post before that said it. I was also confused because I knew the arp bolts had hex heads and nuts were the same.

 

....but your stock nuts are 12 point

 

ARP rod bolts are 6 point nuts... the stockers are 12 point.

Because the stock rod bolts don't dowel the rod cap in place, and the ARP's do, this can cause all kinds of issues when re-sizing. Do a search on the topic, I have written extensively on the process in the past.

JW

 

Can the OP simply remove the oil pan, replace the rod bolts one at a time with ARP bolts, torque the bolts and be better off?

 

No, absolutely not..

JW

 

Not to hijack, but what is the correct ARP part # for a 73 455?

 

Installation for 455 ARP rod bolts and part number - https://cdn.arp-bolts.com/instructions/125-6001.pdf

Jim - I now see why you can't!

 

What I fail to grasp, is why the builder didn't do his due diligence if he was unfamiliar with the task at hand, instead of bull's hitting his way to a paycheck.
All the oil mods and build " secrets" are available by Googling . Not much is "secret" anymore with the internet. He coulda found tolerances, oil mods etc. while eating his bologna sammie at lunch.
The rod bolts are a given, if the thing is cracked open, why not? I do not know the OP intentions with his car or his financial situation, but if he can afford it, pull motor and start again with a well thought out plan . Second option, build a new one correctly and drive this one easily til new motor is complete and ready to install....
I hope you don't feel as thou the collective here is beating you up, more so we would like to smack your machinist about...... Good luck, Jim

 

Builder did it because...….




Puppy!!!

 

You saying the dog made em do it , Steve?

 

Nope. If the builder didn't replace the bolts, He is the puppy.