Hi guys, is the torque spec for ARP rod bolts the same as the spec listed in the FSM? 440 RB thanks.
ARP Rod Bolts
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1967coronet440
Well-Known Member
Look up the part number on arp site it will give you the specs
Roger that I'll give that a shot thanks
Bad Sport
Deceased, But not forgotton
I believe it's 50 ft lbs. http://arpinstructions.com/instructions/145-6002.pdf
Did you have the big end resized after installing these?
Did you have the big end resized after installing these?
Yes they re-sized and also went to a full-floating pin setup. He's a local HP builder with lots of years and a stellar reputation, buuut I'm just double-checking that everything is torqued good before I button it back up...thanks for the link!
Ok. Thanks guys they call for 50 lb/ft for the 145-6002 set which is what I have. If this site's taught me anything, it's to verify all you can no matter who put it together(especially if it was yourself lol!)
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I mic my rods to see if they 'need' resizing and if not, I'll stick in the new bolts. If they go in without having to use a lot of pressure, I'll mic them again and 99% of the time, they are still the same. I will also use new nuts for the final assembly. It's the nut that gives up being torqued and it happens after the first time. Not sure anymore if they still do but ARP used to sell nuts separately.....cheap insurance for sure. Rod bolts usually go into the trash after a season of racing or being torqued more than twice.
Thanks Cranky, the set my builder used included the nuts (he gave me the empty packages from all the parts he used...not sure if that's for my own knowledge base or he just likes unloading the trash on the customer
). Assembling bottom end stuff is something I don't mess with myself...some serious voodoo going on there like in an auto trans I leave those to the pros!
I was told you can't replace rod bolts and not resize rods. I did it anyway but carefully. Explanation is a bunch of typing.
ANY motor I build gets ARP rod bolts and resized. I also highly recommend the customer get it done if they are building it themselves. A little extra money in the beginning will save you lots of heartache when it goes tits up because you cut corners...
Ideally, this is the correct and preferred procedure. I won't say you can't do it without resizing, but I would advise against it.
You are using an experienced builder. You don't know the correct spec. You How are you going about checking the bolt torque? Unless you take them apart, relube and retorque, leave them alone.
Doug
Doug
I personally like to stretch them. it's 0.0059 thousandth's. I think it works out to about 52 Lbs/Ft.
The only thing that torque readings don't tell you is if the bolt is elongating and nearing end-of-life.
The length measurement will tell you this.
The only thing that torque readings don't tell you is if the bolt is elongating and nearing end-of-life.
The length measurement will tell you this.
DCCoronet
Well-Known Member
I went with bolt stretch and ended up at 85ft.lbs.
I don't see the problem in double checking their work? Things happen. Just want to be sure something didn't get left a little loose...I'm not taking stuff apart to re-torque it though, for sure. My wrench clicked at 50 on them, that's all I was after, verified to not be loose..
They do but also instruct to torque to 50 lb/ft if you don't have that stretch gauge.
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I've heard the same thing for 40 years and quit listening to it around the mid 80's.
No corners cut here....but no use in machining something that doesn't need it especially if you have the proper tools to check stuff. No automotive machine shop is going to say that because it's not cost effective for them to spend the time to check stuff and find there's no need to machine a particular part/s. It's a lot faster and more cost effective (there's those words again) to just throw the parts up and machine them. We can talk square decking and align boring next.....
ANY motor I build gets ARP rod bolts and resized. I also highly recommend the customer get it done if they are building it themselves. A little extra money in the beginning will save you lots of heartache when it goes tits up because you cut corners...
Like mentioned above, with the right tools, they can be checked.
Any machine work I can't do in house WILL be checked once it's back in my hands. There's no such thing as a machinist that doesn't make mistakes. I learned that in the machinist trade and was taught during my apprenticeship to check the work of others and always double check your own work. My last significant engine build came back with .0035 out of round in main bearing bores. And this was from a shop that had experience building Pro Stock engines!! Another high profile shop did a block with .0005 hour glass finish in the cylinders. That doesn't sound like much but it is when the pistons are going in with just .0005 clearance!!
If I build the motor, it gets everything, period. If I have to warranty it, it is going to get machined. If a customer builds his own motor, and chooses not to do something, I will be happy to take his money the second time around. Unless you have a $4000 rod gauge, it is going to be difficult to accurately measure out of round to 0.0001". Most people will have a bore gauge that is 0.001" or 0.0005", but that is NOT good enough to qualify a rod bore. Rod bore diameters usually have a 0.0005" to 0.0008" range, and an out of round spec on the order of 0.0001" to 0.0002". As far as align honing, and squaring (in that order) needs to be done to every block. I have seen OEM bores too large, and OOR. I can't tell you haw many blocks that I have squared, but I CAN tell you that none of them were spot on. They can't be that accurate when they pump them out like a pez machine. I could go on and on, and never come to an agreement, but that is fine. I'm trying to eat my fried chicken and keep the keyboard grease free...
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