VinMichael

Asked the local machinist if a line-hone was needed when intstalling main studs. He said no; just reduce the final torque to about 30lbs when using studs. Made sense to me. Anyone heard of this?

Rickman48

No - how does that make ANY sense??
Purpose of torqueing bolts OR studs is to regain the correct circular dimension necessary for the bearing to seat on the main journal!
Incorrect torque leads to incorrect dimensions = out of round bearings = failure!!!
Ask another engine builder or three - - - or check with ARP!!

380 Racer

^^^ x2

dc2x4drvr

Uhhh, find another machinest..

11971four4two

Just say no!

Find yourself a different machinist who knows what he is doing

cutlassefi

Better yet, run the hell the other way and make sure you tell all your friends as well.
As a matter of fact, who is it? All on here should know as well.

joe_padavano

Just to clarify slightly, the primary purpose of torquing any fastener is to ensure that the proper preload is in the fastener. This is necessary for two reasons. First is that the fastener stretches as it is torqued. If it is not stretched to the pre-determined tension, it will not provide the intended clamping force and thus not carry the intended load. This is why top engine builders use rod bolt stretch gauges instead of torque readings. The second reason (which is related to the first) is that this preload is necessary to ensure that the fastener doesn't loosen under vibratory loading.

This relates to what Rickman posted in that for engine applications such as cylinder heads and main or rod bearings, the preload in the fastener also distorts the casting or forging, and since the mains were line-bored with the fasteners fully torqued, yes, they will not be round if the preload tension is not the same.

VinMichael

Thank you everyone for your input. However, the machinist's statement made sense to me, because the TPI count on the ARP main studs are much finer than the original bolts. Since the threads are finer, the nut will make more revolutions on the stud; in turn, less torque would be required to achieve a sufficient clamping force. This engine will be going into a street/ occasional strip car at Infineon Raceway, Sonoma CA.

MDchanic

Yes, but ARP has this all figured out already.

Do what ARP tells you to do.

- Eric

joe_padavano

While that statement is true, tests on fasteners repeatedly show that the majority of the friction that counteracts torque comes from the face of the nut (or the underside of the head of the bolt) rubbing on the item being clamped (or the washer under the nut), NOT the threads. Thread pitch doesn't change this.

bigD

there is no way in hell i'd use that machinist!!!!

VinMichael

I will be discussing this matter further with the machinist and will be following whatever advice is given. I will let everyone know how it turns out also.

compedgemarine

OK I am a little confused by this whole thing. you are wanting to install main studs which ARP spent lots of money developing so that they will allow better clamping when done to their specs but you dont want to align hone it but rather just not tighten them to spec. why are you even wasting time 1) installing studs to end up with less clamping than just putting the original bolts in and 2) listening to a machinest that is telling you to listen to him over the people who developed the studs. I dont mean to come across rude but I see this over and over were people decide to listen to someone other than the manufacturer who spent the time and money to develop something and then complain when it does not perform up the the expactations. the main bolts are plenty strong enough for most street engines but if you feel you are going to be making enough power or rpm to need studs then do exactly what ARP (or the stud maker) is telling you to do.

MDchanic

I think Compedge has summed it up perfectly.

- Eric

cutlassefi

x3

m371961

I would go with ARP. Torque is a measure of the clamping force and I do not see how it matters that the studs are SAE threads. Isn't it how tight they are, reguardless of the movement of the fastening device except for the friction under the bolt/nut head and threads? I am no mechanical engineer, but ARP certainly uses them. I would also install them and check the bore alignment. I would also check with ARP about torque and re-torque to assure the new bolts are stretched before final torque and assembly.

VinMichael

I casually asked the machinist about the Main Studs as I was picking up my block.

He stated, "those are not needed for my application, bolts are fine."

I then asked, "What if I already have studs?"

He said, "screw them in finger tight, and then 'synch' them down."

I asked, "So like, 40 pounds?"

He said, "No, like 30 pounds."

I said "bye", then I got in my car and left.

All the stuff about the tread count and all of that in my earlier post, was just my own reasoning in trying to understand his thinking.

I have not decided if I will use studs or the original bolts. Although, since I have ARP studs, why not use them? I admit that am attracted to the "idea" of using studs, since they are used on motorcycle engines which I work on; and allow room for error (imo), such as stripping threads (which sucks). So, that is why I would like to use studs, I think they are just practical fastener.

I may end up going with the bolts, but I trust the machinist advice which has never steered me wrong. Although, I do admit I have not completed an entire engine rebuild with him, thus far. I have only sought his assistance and guidence for smaller jobs, which were succesful. He is respeced in my town, and has been in business for longer than I have existed on this earth. That is why I trust his advice.

compedgemarine

I would say that he has been giving bad advice for years then. ARP calls for 110 pounds on oldsmobile main studs (at least for 455 with 1/2" studs). 30 pounds is the average torque for a 5/16 bolt! if you listen to him and torque the main studs to 30 you will be lucky if the engine lives past 2500 rpm. I would say if you have the studs but this is a mild street build use the original bolts and save the studs for when you want to build bigger power and are going to have other machine work done and you can install them and align hone it then.

MDchanic

Agreed.

I would say that he is half right. The half about your not needing ARP studs in the first place.
Just use the original bolts and torque them to spec., that way there will be no doubt and no conflict regarding whose advice to follow.

- Eric

Rickman48

We may be condemning a misunderstanding, too.
He may have been talking about the torqueing of the studs into the block!
I personally don't know the correct specs, but that sounds more reasonable for the answer received!!

compedgemarine

you dont torque the studs into the block. you just run them down finger tight. if they are going to stay for a long term you can put locktite on them but I dont know of any studs that are torqued into the block.

VinMichael

I appreciate the feedback. I will be using bolts, and save the ARP's for another day. Thank you everyone who took the time to post and answer my questions in detail!

cutlassefi

You're exactly right compedge.
When I did kyles build (it's on here) last year, he showed me pix of the machine work being done to the assembled short block he bought. 1 pic showed the line hone in the main saddles with bolts holding the main caps on. The very next pic showed the crank installed with studs and a girdle. He had just a little over .001 clearence in the mains and the bearings showed signs of pinching on the sides. He would have spun one for sure.
Your machinist is clueless, which would be unsettling to me if he did anything to my motor.
Jmo

roscoep41

I have been an engine machinist for 25 years. I always resize after replacing rod bolts or main studs. main studs should be seated in the block. 30 ftlbs sounds good to me. the torque for the nuts should be the same as a bolt torque if they are the same size.

m371961

I think a lot of us took the comments in the early message as the machinest saying to torque caps at 30, I am sure now he meant to tighten studs down to 30 or so. That sounds reasonable to me. But I would want alignment checked if studs are installed. Good luck and I hope you get to enjoy it soon.

VinMichael

Yeah, I hope so as well. Bolt's are going to be used this around, unless the machinist suggests otherwise. I plan on dropping by his shop sometime this week to confirm.

bigD

as stated earlier, you don't torque studs when you put them in the block. you also want to be sure that they don't bottom out in the holes they are used in. if you torque a stud or bottom it out in the hole you are creating a massive stress riser and run the risk of block damage!

cutlassefi

Then I would never allow you to machine anything for me. ARP hasn't recommended anything other than finger tight in over 10 years. Apparently you don't read directions, hence the reason why I would never let you touch anything of mine, ever.

BigD, you are correct, thank you.

coppercutlass

Mark if you are a buisness man how do you run around talking to people like that. You do realize potential customers see that as un professional. joking or not its borderline condesending.

cutlassefi

Point taken. But let me ask you a question, how would you feel if by chance you are able to avoid a potential problem because you notice a drug interaction issue that your Pharmacist and/or doctor missed because they quite simply didn't read the effen directions? Maybe a little far fetched but the simple fact is he's dead wrong, period, All because he didn't take 2 minutes to read the directions, by his own admission he's a "machinist of 25 years".

The internet overall is a good thing. BUT there is a lot of downright bad info out there, I run into it all the time on the EFI stuff. You say for a business man I should take a different approach, he should know his "business" too don't you think?
And on top of that, there's nothing that says a stud with a nut vs a bolt should take the same amount of torque. Guess what, he should know that the loading is different on a stud vs a bolt. Put a torque plate on a block, then check the out of round with bolts. Do the same thing with studs, I'll bet you a days pay they pull differently. Again he should know that.

With a stud torqued before you install the nut, you're now loading the threads twice. And for the record, BigD was pretty emphatic as well, and rightfully so.

coppercutlass

I understand a man can be wrong but how it is addressed is the issue . Im guilty of this at work. big d did mention why not to torque it and im not bashing anyone or trying to make anyone look bad. I do body work for a living and i can tell you., you can talk to 3 body man on their procedure for using body filler and i bet you get 3 diffrent answers. I bet if you talk to 3 engine builders you will get 3 diffrent answers as to their procedures for block prep, building etc. Btw i agree with what you guys stated. Im just saying dont attack the man., say why that could be a bad idea and move on. Facts are only facts to those who take them as what they are some disregard them and belive what they want to belive and in fact we sometimes share opinions as advice . Im pretty sure when someone invented the wheel someone said it was a stupid idea and some said it was the way of the future. Those who said it was dumb where entitled to their opinion but it didnt make i so. I completly agree with you if you can catch a mistake why not BUT if some tells me nope nope your wrong you obvioulsy cant do your job then yeah i will tell someone go pound sand im gonna do what i normally do. If someone said hey you might wanna think about this and here is why then i would probably listen.

bigD

i've gotta go with cutlassefi on this one, i saw nothing condescending or out of line with his response. to me it's pretty simple, you learn the proper procedure and then you do it that way... especially if people are paying you! i cringe when i hear people talk about changing rod bolts without resizing the rods... i can't imagine changing over to main studs without doing a line hone after properly torquing the main caps...

coppercutlass

It can be take as condesecending is all im saying. Telling someone you would never allow them to machine your stuff to me is like a slap in the face becasue now you are driving the point his skills arent up to par . I think he could have just said arp hasn't recommended anything other than finger tight in over 10 years . You dont need to tell the guy he is not worth your time imo that has nothing to do with the subject at hand. I understand if someone is wrong correct them but dont tell them they are not worth your time or money.

380 Racer

I agree with Mark, I mean is if a guy buys ARP studs he should do it totally right. Why come on a forum and ask if you aren't going to listen to people "in the know" anyway?

bigD

seems to happen a lot doesn't it 380, seems that most of the time their minds are made up before they post, they just want someone to reaffirm their poor descision... this one blows my mind tho!!

MDchanic

Okay, I'm not going to bash anyone or get into any arguments here (enjoy it while you can!), but I DO want to clarify something.

If I am correct, the proper way of installing ARP studs is to screw them finger-tight into clean, thread-chased holes with a bit of motor oil (ARP-supplied oil to be used on nuts), and if the stud bottoms in the hole, or if the shank bottoms at the top, then back off about a turn.

I've got plenty of experience with stretch bolts on German engines, so that's no mystery to me, but they've always been bolts, not studs. With non-critical studs, like for valve covers, I have always just bottomed them.

- Eric

coppercutlass

I will say this I'm not saying that the guy who said to torque the studs is correct. I just said show him where he is wrong and that's it don't tell him he aint worth your time that is kind of insulting imo but I could be wrong. I agree with you guys on the studs I have never used them but I would also follow arp's directions to a tee. I don't think his minds was made up he said he was going to just use the bolts and leave the studs for a later project as vin stated.

ah64pilot

So I just read this whole thread and I have a couple of points I would like to make:

1. Copper, you are correct in that EFI could have used more tact to tell roscoep41 he was incorrect about his stud torquing procedure

2. EFI, I have main studs in my engine and you are totally correct - I have no arguments, I just want 380 and BigD to understand that Copper was really just commenting on your statement:

"Then I would never allow you to machine anything for me. ARP hasn't recommended anything other than finger tight in over 10 years. Apparently you don't read directions, hence the reason why I would never let you touch anything of mine, ever."

Tact is all I believe Copper was trying to get at, not the actual correctness of your statement. Now, for the OP

I don't know your background but I would like to address the fact that you join an all Oldsmobile forum and ask a specific question to which you were given consistent replies. However, because of your machinist's age you are going to ignore the advice that was given by OLDSMOBILE builders and professional machinists or long time racers...does that make sense to anyone? It sure as hell confuses me...but what do I know? I only trust my machinist, but then again, my engine was done next to a Pro-Mod engine...not an '83 SBC

VinMichael

I don't know your background but I would like to address the fact that you join an all Oldsmobile forum and ask a specific question to which you were given consistent replies. However, because of your machinist's age you are going to ignore the advice that was given by OLDSMOBILE builders and professional machinists or long time racers...does that make sense to anyone? It sure as hell confuses me...but what do I know? I only trust my machinist, but then again, my engine was done next to a Pro-Mod engine...not an '83 SBC [/QUOTE]

No, I have taken everyone's advice into consideration. I have decided to use the original bolts that came with the engine. The only reason why I wanted to use the studs for my build was because, well, I think studs are a superior fastener. Why do I think this? Because studs allow room for error, which I expained earlier. I appreciated everyones feedback and respect everyones viewpoints. I do plan on upgrading this engine in the future, then I will use the studs when they are neccesary, which they are not at this point in time. Thank you everyone for you inquery and response.

cutlassefi

No, I have taken everyone's advice into consideration. I have decided to use the original bolts that came with the engine. The only reason why I wanted to use the studs for my build was because, well, I think studs are a superior fastener. Why do I think this? Because studs allow room for error, which I expained earlier. I appreciated everyones feedback and respect everyones viewpoints. I do plan on upgrading this engine in the future, then I will use the studs when they are neccesary, which they are not at this point in time. Thank you everyone for you inquery and response.[/QUOTE]

I guess I missed that, I don't understand that statement. As far as my comment, maybe I could have been less emphatic and more tactful. However I still wouldn't let him touch anything of mine.