ARP Rod Bolts

[ChrisS]

When I was dissembling the engine that I grenaded I ran into a problem with the ARP rod bolts I had installed. When I loosened the nuts the bolts rotated such that the heads stick out too far and would let the big end through the bore. I didn't notice until it was too late and by then two of the rings had popped out sort of locking the piston in place. I double nutted the rod bolt and got it rotated the other way but it was a real pain. (I have the proper rod bolts by the way; these aren’t the big block Chevy ones.) Has anyone else run into this problem?

 

[Hap Waldrop]

Chris A-series rod bolts are for all practical purposes are a slip fit, it's not uncommon for them when loosened during disassembly to rotate and make it hard to get them out of the bore, if you want them to fit a little tighter in the future, do some Polish knurling, I just take a p-r-i-c-k punch ( a skinny center punch ) and make a few taps in the ID of rod bolt bore this will give you just enough resistence to keep them from turning. Sounds like you have the ARP # 206-6001, which are the correct ones, stay far away from the big block Chevy ones. Hope this helps

 

[Hap Waldrop]

It sad affair when can't even type p-r-i-c-k for a good reason /ubbthreads/images/graemlins/smile.gif

 

[ChrisS]

Thanks Hap, I'll try that when I put it back together.

 

[jollyroger]

What is the problem with the big block rod bolts on an A series? I have them on all my race and street engines. A bit of work to make um fit right but once ya get it right the rods stay put. Very tight fit with the knurled shank in both halves. Better n any standard stuff and way cheaper than the Arp A series units. Going on twenty years using them with zero failures. I wish someone would of told me they were no good before spent all those years doing it wrong.

 

[jlaird]

Maybe it's just cause you live right Jolly. hehe.

 

[ChrisS]

I wasn't implying that using the BB Chevy hardware was wrong just that I had the ones that ARP designed for the engine.

 

[Hap Waldrop]

I'll take on the BB chevy bolts, let see where do I start the nut is wrong, you can't hardly get a socket on it, the head of the bolt will not retain itself against the rod and the entire rod bolt could turn if it should work it self loose and that's the beginning of a big failure and exactly what I saw them do in the past. The wave ARP BB chevy bolt are way too hard of a press fit and stress the rod itself, the knurled units have to dead nut in knurl reduction on they could spin and if not reduced again are more than the average press fit which stresses the rod . If you have used them with sucess, congrats , I will never use them. Since the BBC bolt require the builder to modify for use, then eveything relies on the modifcation and how well this is done, so ok both will work, one with a little work if done properly, and the only reason to buy the BBC bolts is to save a buck, rod bolts are not something I'm looking to save a few bucks on. I absolutely refuse to use them in my race prepped rods, no exceptions. Most professional race engine builders over time have seen the same thing and refuse to use them as well.