Re-using Rod Bolts

[66FAIRLANE]

So this low use engine had a set of ARP rod bolts in it when I tore it down 23 years ago. I put them back. It had a freshen up about 13 years ago. I put them back. Its soon to be assembled again. Will these go around again or is it time for new ones?

Just a street car. Standard rods. Saw 6000rpm a lot with occasional 6500 plus over those years.

[67xr7cat]

Rod bolts and rods for that matter have a fatigue life. Usually on rod bolts you measure the bolt length before first use. If they measure the same (not longer) they are considered good as long as they don't show any physical damage or rust.

That all said given the use over the years I'd be putting a new set of rods in as an insurance policy. Is just hard to say when their time will come and that is the problem.

[Falcon67]

Well, the correct way is to measure the static length of the bolts, then install using a stretch gauge.  Then measure again during service.  If the bolts have stretched from the base measure, probably time to replace.  I usually figure 4~5 uses on ARP bolts.  IT's not cheap to replace, but potential damage is a greater cost.  FWIW, the same ARP bolts have been in the Falcon's 351C street/strip engine for about 15 years and well over 3000 passes on the drag strip.  No worries here.

[C6AE]

It's all good until you lose one at 6000 rpm, only then do you appreciate how cheap they are.

[66FAIRLANE]

Thanks guys. I had pretty much resigned myself to replacing them but thought I would check in case I was being stupidly cautious.

[gdaddy01]

need to redo big end of rod after changing rod bolts ?

[My427stang]

I am the oddball in this group maybe, but I think the bolts will live a long time if you haven't overtorqued, the rods themselves would be my fear over time.  I have seen Ford rods break right in the middle in mild applications.  Any chance the budget would support a set of new aftermarket? 

[66FAIRLANE]

With the Aussie dollar near a ten year low against the greenback & recent changes to our imported goods tax legislation I am having to shelve some of my plans which included hyro roller & possible stroker kit. I will be putting it back together as a 390 with an old Crane Fireball 294 I haven't run in 20 years. The rotating assembly was reasonable (although old school) when I built it years ago. Crank was crack tested, index ground & stroke matched, rods were resized, length matched, little ends done & the whole lot balanced with TRW F2291's. All of that is still in good condition with no touching necessary so unless the dollar starts to pick up real quick a spare block gets machined, new rings, bearings & it will be going back in.

Yeh I worry about fatigue & the stock rods were probably the weakest link but I just couldn't bring myself to buy rods without a 4.25" arm!

[JamesonRacing]

The stock FE rods are pretty darn tough.  I've broken a lot of parts over the years, but never had a rod fail me.  I wouldn't change bolts unless I was doing a full refurb on the the rods.

[My427stang]

I'd run it....

[338Raptor]

Rod bolts could be the weak link at high RPM.  Rods are a weak link with high horsepower and high hours of use. 
I would be more concerned with your rods if you plan to make high horsepower. 

[C6AE]

I have broken (Ford) rod bolts on 2-V 352's
The result is almost always a windowed block.

[Posi67]

I'd run it....

So would I... I've broken stock rods (more than once) and in spite of all the carnage the ARP bolts didn't give out. I don't even use the fancy ARP's  just the standard ones because I have that much confidence in them. BIG HP, different story though.