torque on main studs..

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NorwayCuda69

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Here is one for ya..

what torque is needed on arp main studs.. i don't want the clamping force to overcome the original to much cus i don't have the possibility to align hone the block. right now i have the plastigauge in the bearing surfaces and im about to tighten it up.. hmm if u don't know the right answer, pls don't reply.
 
arp website and instruction says hand tight.
 
You didnt align hone the block???!!!! Dont use the studs. Put the stock main bolts back in. You cannot run studs without having it align honed, and leaving the studs loose to keep the preload down is a really, really stupid thing to do. You are MUCH better off using the factory bolts as opposed to the two stud alternatives. Plastgage will not show the distortion much if at all.
 
hmm i found it to be 65 - 70 lb ? on a forum.. that is recomended torque.. hand tight sounds a bit odd to me. :) maybe right
 
moper said:
You didnt align hone the block???!!!! Dont use the studs. Put the stock main bolts back in. You cannot run studs without having it align honed, and leaving the studs loose to keep the preload down is a really, really stupid thing to do. You are MUCH better off using the factory bolts as opposed to the two stud alternatives. Plastgage will not show the distortion much if at all.
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Agreed! Do not use studs if you haven't had it align honed!!!! I made this same mistake over twenty years ago when I was a kid and lost oil pressure in 10K miles.

NorwayCuda69 said:
hmm i found it to be 65 - 70 lb ? on a forum.. that is recomended torque.. hand tight sounds a bit odd to me. :) maybe right
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Hand tight refers to the studs in the block, not the torque on the nut. ARP studs should also be torqued using their lubricant or oil and the torque specs are different for both and it also varies with the tensile strength of the bolt. The 1/2" 180k series torque values are 108 ft lbs with 30W and 84 with the ARP lube. Got a part number so we can get the correct specs for you?
 
more info.

nope the block is not honed.. no machine shop here can do this. i rly cant c why the studs will make the caps not aligned?? only the downclamp will prolly be somewhat more?? just torque untill it gives ca same downclamp as std.. the std bolts dont have the mounts for the tray.. thats gona be a problem, dont want to weld on em :S .. anyways here is what i found with 67 ft. lbs (that suposed to give the downclamp u have with 95 ft. lbs std bolts acording to some forum)

plastigauge 1.jpg


plastigauge 2.jpg


torqyed.jpg
 
id better move my *** down to the states where there are some machineshops around.. the bore alone came at 1000 dollars + 20% tax hehe no tools for align honing there.. only the bores could be done.
 
NorwayCuda69 said:
id better move my *** down to the states where there are some machineshops around.. the bore alone came at 1000 dollars + 20% tax hehe no tools for align honing there.. only the bores could be done.
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I lived in Germany for almost 10 years! I know they had a couple of specialty shops, I also believe Sweden had a few. I can't remember the names, sorry. But I found them in one of the American car magazines. I believe it was "Chrom und Flammen" I'm not sure if it is still around. I'll check through some old issues and see if I can find an address. The studs locate the caps total different then the bolts do! The miss alignment is not much, and you might get lucky! But if you waste that crank or that block, it could be an expensive lesson!
 
The issue is clamping force. As any bolt is tightened, the iron cap and block distort. The block is then machined to the right bore size and to get it straight. If you do anything to change the fastener, or the cap, the bore needs to be re-machined. The stud clamps the cap much more firmly because there are more threads engaged and the stud doesn't stretch the same way. So the cap and block distort differently under the load of the stud. You cannot measure these with plastigage. It's a twist and deforming of the bore. Plastigage is like measuring spark plug gap with a ruler. It can come close. But it's not really likely.
 
moper said:
The issue is clamping force. As any bolt is tightened, the iron cap and block distort. The block is then machined to the right bore size and to get it straight. If you do anything to change the fastener, or the cap, the bore needs to be re-machined. The stud clamps the cap much more firmly because there are more threads engaged and the stud doesn't stretch the same way. So the cap and block distort differently under the load of the stud. You cannot measure these with plastigage. It's a twist and deforming of the bore. Plastigage is like measuring spark plug gap with a ruler. It can come close. But it's not really likely.
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sooo, i think the table under the arp box shows clamping force.. mm u think we couldfind the typical clampforce with the std bolts? would be the only option. hmmm the std should not give exact the same every time u tork em down... i feel the best is yes rip it apart and clamp down with desired force.. check roundnes with a snap gauge??
 
You're re-engineering.. so you're on your own...lol. the right way: You use a good fastener to hold it better. Then you machine it so that better fastener can work as it is supposed to. You're trying to get the better fastener to do the same thing the factory one does.. and that better one is not designed to be used like that. If you distort the bore the same way as a bolt. You have no extra strength. Why not just use the bolts instead of the studs?
 
moper said:
You're re-engineering.. so you're on your own...lol. the right way: You use a good fastener to hold it better. Then you machine it so that better fastener can work as it is supposed to. You're trying to get the better fastener to do the same thing the factory one does.. and that better one is not designed to be used like that. If you distort the bore the same way as a bolt. You have no extra strength. Why not just use the bolts instead of the studs?
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hmm i would like to keep the studs cus they have the windage tray fasteners. tough, i have a set of 340 original bolts with the mounts.. thoug i think they are a bit shorter cus of the smaller 340 mains.. ( i want to cry now) i want an align honing machine for my b-day
 
lol... sorry Norway. You can always get some threaded rod or longer grade 8 bolts and use the stock mains bolts. You'll need to fab up your own "studs" for the tray, and use two self locking nuts to get the tray set properly.
 
i have done that before, i bored and threaded the top of the main bolts then i put carburetor studs in the holes, silver welded in place this was for a toyota mr2 turbo.... mmm but i think the welding/heating will weaken the bolts, same will the boring in the head.. ugh.. cant u send me an "drillbit align honer" hehe..
 
my 2c

MOPER is right: it's about clamping force..
the main caps do not align around the bolt/stud, but on each end of the cap. The only reason for aligh-honing is that the studs actuate so much pressure on the cap that the hole coming out of round....in my fantasy world, just a tiny bit!

some proffesional engine builders have measured with bolts vs studs,and do not find any change in bore diameter...
(I have to get their names,right?)
EDIT:Tom Waters(old hemis) ,

I believe that we should be more conserned about capwalk and general bouncing of the cap!
Remember this is a high-hp stroker ...


I bet the reason all big ones say you have to align bore is because they won't be there when you have blown the engine...

it's better to say: I told you so:-D

better safe than sorry...?

EDIT: after stumbling around on the internet, it seems that most engine builders have seen no change in ovality after changing from bolts to studs from time to time. somehow, most often the bore is out of round! and most say around half a thousand! even when align-honed, some also report change after remove,clean and retorq with fresh honed bore and studs.

Let's say: allways do a check! and in most cases,you need to align hone or bore! You COULD be lucky and measure no difference! for us,where we live in norway, thats about $1000 saved!
 
Ok. I agree on looking. I've never measrued one that didnt change shape. At least buy the dial bore gage and learn how to use it. Plastigage wont "see" these changes.
 
The problems we stumble upon, is the werry reason i do this.. if it was all go i would have bought a crate engine instead..

http://www.summitracing.com/parts/ARP-240-5501/ is the mains i have now.

my friend workes at an aircraft engine shop, they must have the dial bore gage.. maybe i could lend it.. or bette he learn me to use it..

In anyway thank u Moper for trying to help me not wreck this engine :) i will report back how the messures is going.. with some different torques
 
moper said:
Ok. I agree on looking. I've never measrued one that didnt change shape. At least buy the dial bore gage and learn how to use it. Plastigage wont "see" these changes.
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im sorry for the plastigage thing... bt it wasnt ment to find the missalignment.. i didnt rly think of this issue before i was assembling the bottom part... the p gage was simply placed there to ensure the beraing clerances was ok. and it was only placed on top of the crank surface.. if it explane the missunderstanding..
 
Nomisunderstanding. Plastigage has it's place. It will give you an idea of where you're at. I've used it myself (still have some in the tool box..) with good results. But at the level you are playing with, you need more than "good". You know? Let us know how yours turns out.
 
tnx agen moper!!

here we go... i calibrated the dial gage to 72,50 mm exat from there i mesured all the bores and made a table on it, that i posted in here. first 0 degrees that is vertical. from there i turned 45 degree and mesured ... so on. i tested both 55 and 84 ft lbs with the arp lube. the numbers that changed was on a few hundreds mm as u can see.. looks like the cap tend to bend inwards as u aply pressure where the 45 and 135 degrees are mesured.

I also made a discovery. the nr 1 bore was a bit more off when i started.. found that the cap leaned against the right hand studd. this made sutch press that it pulled the cap over a bit (cuple more hundreds). i honed the hole in the cap, it went on smooth and the bore came out like in the table.. this could have been fatal i think. haha now u have prolly saved me a cuple of k$ .

this weekend i go back to my garage (that is where my parents live) and get some std bolts and try ho they worke out.

måle 3.jpg


måle 1.jpg


linjeborr.jpg


måle 2.jpg
 
Since you posted the pic of the #5 main... the stud on the passenger side will nee a smaller nut (ARP sells a 12pt kit... that's what I use...) and the stud needs to be cut down. Otherwise the oil pump will not seat properly. Just an FYI.
 
moper said:
Since you posted the pic of the #5 main... the stud on the passenger side will nee a smaller nut (ARP sells a 12pt kit... that's what I use...) and the stud needs to be cut down. Otherwise the oil pump will not seat properly. Just an FYI.
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yup there came 2 nuts like that in the kit, now i know why, tnx.. i will cut 1 of the windage bolts since the millodon trayhas only 4 bolts. ...
 
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