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Discussion Starter #1
A NOTE TO THE WISE for all. out of the 25+ ENGINES i,ve been involved with rod bolt failer has been the culprit quite a few times. as you,all know this will ruin your engine if you have a rod bolt failer. a word of advise to all. if you change you engine from stock in any way.......... install aftermarket h/p rod bolts and if you go to real hi boost turbos install head studs preferably the over size ones. just my opinion. every engine i build will have at least the h/d rod bolts. remember cummins is all made overseas now mainly brizil so keep this in mind fellow souper uppers . better to over build that not to n the fastener line.
bob in tn.
 

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I agree. I have one that I keep for measurements. Cyl #4 failed by totally tossing the rod cap and nuts throught the camshaft and exiting the block leaving the rod sticking out where the camshaft once was. I think this was a runaway engine that had the turbo oil seal fail which permitted the engine to run ungoverned on its own engine oil as fuel.
 

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i bet it burnned that piston & locked it up in the bore then katy bar the door. how did cyl. wall look ? #4 piston gets the hottest of em all cause its the farthest from the rad. # 1 runs the coolest in turn. nature of inline engines. just my opinion.
bob
 

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What kind of HP are you talking for ARP rod and head studs? I'm planning on maybe 175 HP or so with just a pump turn up with HY35 and air to air cooler. Should I do the rod studs?
 

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Discussion Starter #6
well, 52 wrench seeings how your wanting to increase hp & torque by 70-75% yes i,d stud and rod bolt it. you better know what your doing when you do thiese swaps ... what are you going to set your timming at to go along with the added boost & fuel pressure ? what compression pistons are you going to run ? stock wont be compatable . theres more to it than just fuel and boost. its takes the whole combination. coated pistons help but they wont keep you from melting them. egt,s soar extreamly quick.
bob
 

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OK, I'm looking at the ARP catalog and they don't show any Cummins rod bolts, only head studs, maybe I'm missing it somewhere.. What rod bolts do you recommend? Its probably cheap insurance. I think I'll stick with the stock head bolts, I don't plan on over probably 24-25 boost, stock should be OK for that as long as they are not beyond the stretch limit. Thanks.

Steve
 

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Yeah, that's what I was thinking. I think rod bolts are less than $75, head studs more like $300-400?
 
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