Since we got a little derailed, and generally out of control last night , I wouldn't mind getting back into where we were going, without the drama.

The majority of guys today are probably using some brand of H beam rod here. Curious as to what rod bolt is favored, and at what level is the upgrade necessary.

We have the standard 8740, ARP2000, and L19 lets say. There is talk about the L19's being affected by moisture, and hydrogen embrittlement. Is that a real concern, or is it simply internet hype? I know alot of guys have had scenerios of water in the oil, from maybe reversion, a leaky intake gasket, or things of that nature. I can only go off what I've read on ARP's site, about those bolts. I personally have never used them in anything.

At what level should one consider upgrading from the 8740 bolts, and which bolt is preferred? Mainly talking about your average marine BBC staying well below 7k RPM.

Yes but what about in a 4.25 stroke application like yours? As far as the power level, would a engine that makes 900hp with a roots blower, be seeing more stress than a N/A or turbo engine since the roots blower is probably consuming 100hp to turn ?

I don`t know so Ill just keep out of this.

I'm obviously no expert, but i think you have to make a judgement call on stroke, weight of the piston/rod assembly, crank stroke, and max operating RPM. Most of us who are running a max of 6K or so are just fine with the 8740's.

I'm running 8740's and Eagle I-beams in my 489, but it won't see more than 6K RPM (probably a lot less than that), and the smaller bore probably results in a lighter piston assembly.

For the record, I have heard some talk that there are some Chinese knock-off 8740 rod bolts floating around out there, so make sure you get any replacement bolts from a reputable source.

Personally, unless I was building an absolute max effort large displacement engine that was going to be spun regularly above 6500, I would avoid running the L19's, because I would always have the worry of some moisture from condensation or a leak somewhere causing problems. Seems to me like moisture could get to them even over the winter if condensation were to occur inside an oil pan on a rod bolt. Perhaps that won't happen since it is inside the oil pan, but I would still be concerned about moisture.

Hopefully some of the pro's will comment, but after the mods had to break out the Ebola-grade disinfectant last night for the oil pump thread, I can see where everyone might be a little gun shy.

Probably a wise decision. Now go fix a furnace - somebody's freezing their azz off up there in the frozen tundra of Chicago!

The most murderous action placed on rod bolts is when the rod stops and then starts and continues to accelerate back down from TDC on the exhaust /intake stroke. IEverlap.

No compressive forces helping to keep the piston + such pushed towards the rod cap.

So, its not really horsepower, it's rpm's vs piston/ring/pin/ good part of the connecting rod itself weights that's trying to seperate from the connecting rod's cap.

All my IMHO of course.

Lets say we have two 540's, with identical rotating assemblies. One is 700hp NA, and the other is 1100hp with 10#'s boost. They both turn 6000rpm. Would the boosted motor require stronger rod bolts then the NA version? If so, why?

Neither do I but that's why I'm asking.

I'd like to say yes, because of the higher cylinder pressures. But ....is the peak cylinder pressure actually higher in the blown engine, or is it simply the same pressure just carried out longer during the stroke?

The main issue with the L19 bolt is when it is manufactured. Yes, stress corrosion can in extreme cases weaken it, however, as confirmed by Callies, it's not something that materializes in the real world. I will call them again Monday morning and provide their findings on the L19 so we have some data.

Budman- Think about an oils polarity regarding metal surfaces, and you soon realize it would take a decent amount of moisture to disrupt the balance. Just food for thought.