Can you change Head studs 1 at a time?

[JD Dave]

Without pulling the head on a motor that has never been run before. The motor I bought has regular Arp's and I think since I'm going with big twins I might be better off to switch them to 625's before I install it. I really don't want to spend the money on 625's right now but I really don't want to have to pull the motor to change them later. Any thoughts?

 

[TrentNell]

Without pulling the head on a motor that has never been run before. The motor I bought has regular Arp's and I think since I'm going with big twins I might be better off to switch them to 625's before I install it. I really don't want to spend the money on 625's right now but I really don't want to have to pull the motor to change them later. Any thoughts?

If the motor has never been ran you can pull all the studs and re-install all the new ARP's and just re-torque the head , if its been ran before you can do them 1 at a time , but i dont trust it as much as doing the whole head , especially since the new ARP's have a higher torque spec .

 

[JD Dave]

If the motor has never been ran you can pull all the studs and re-install all the new ARP's and just re-torque the head , if its been ran before you can do them 1 at a time , but i dont trust it as much as doing the whole head , especially since the new ARP's have a higher torque spec .

Thanks Trent. Do you think this would be a wise decision to do them? What studs are you running?

 

[TrentNell]

Thanks Trent. Do you think this would be a wise decision to do them? What studs are you running?

I am just running the standard ARP's , for myself beings the preimium studs are tripple the cost of the standards i chose to wait and see , if i loose a head gasket I will upgrade later 1500 bucks was just too much to spend IMOP for just bolts and nuts , but so far so good , and BigBird is still on standard studs also and he has been running 90 PSI boost .

 

[JD Dave]

I am just running the standard ARP's , for myself beings the preimium studs are tripple the cost of the standards i chose to wait and see , if i loose a head gasket I will upgrade later 1500 bucks was just too much to spend IMOP for just bolts and nuts , but so far so good , and BigBird is still on standard studs also and he has been running 90 PSI boost .

Thanks I think you just talked me into leaving them. I'll keep my fingers crossed they last a year or two.

 

[DIESELMAFIAPER.LB7]

i knew it they are good for more then everyone has said! well i feel alot better bout getting regular head studs then

 

[IOWA LLY]

If the motor has already been ran, why don't you break one at a time loose, apply arp lube, and re-torque to 125ft lb, following gm sequence.

This way your not over tightening anything your just re-torquing them which is recommended by arp anyway.

 

[jckleewein]

Thats what I am planning on doing. Replace each one, one at a time.

 

[JOHNBOY]

Was the block bores honed with deck plates? I would not Switch studs without honing with a deck plate. They will torque different and the bore will distort. This the reason I dont reccomend just adding studs. To do it right you should hone with deck plates.

 

[Smokin LB7]

Was the block bores honed with deck plates? I would not Switch studs without honing with a deck plate. They will torque different and the bore will distort. This the reason I dont reccomend just adding studs. To do it right you should hone with deck plates.

So are you suggesting that it is necessary to pull the motor in order to do headstuds/headgaskets and completely tear it down and rebuild it?

 

[JOHNBOY]

So are you suggesting that it is necessary to pull the motor in order to do headstuds/headgaskets and completely tear it down and rebuild it?

IMHO Yes.
The trouble is the studs apply so much more force. Which is why one installs them. That force also distorts the bore when you tighten them. It can distort the bore as much as .004-.0045 when going form stock bolts to regular ARP studs. Using torque plates allows you to tighten the studs as they will be on an assembled engine then hone the bore to size and shape.

This is far better for bore size and shape. Which helps make power thru a better ring seal and lessen the chance of splitting a piston from lack of clearance.

 

[SIKDMAX]

Im running the 625s, but Im scared of having to pull the motor again so I went as best I could.

 

[jckleewein]

Not to hijack the thread, there seems to be a lot of people out there who replaces the head studs without re-boring the block. Right or wrong, how many trucks have had failures for not boring the block with the head studs in place? The 625 head studs require 25 more lbs. of torque then the standard ARP head studs. Do you think the 25 more lbs. is really going to deform the cylinder? Sorry for the dumb question.

 

[jckleewein]

Im running the 625s, but Im scared of having to pull the motor again so I went as best I could.

What do you mean by best I could?

 

[paint94979]

What do you mean by best I could?

the 625's are stronger than the standard studs no one will dispute that

 

[jckleewein]

I wasn't forsure what Matt meant by that.

 

[SIKDMAX]

I built my motor with the intentions of doing it once, the best I could, even it if cost more money (it did) and taken longer (it did ).

Thats not to say that I wont be rippin it out or changing parts later, but I know I would have been upset with myself if I spent all this money, but big twins on, and blow a headgasket due to the heads lifting.

That was my reasoning for doing the ARP 625 Customs over the standards, or spending more $$ to have my injectors fully tested, etc.

FWIW, it seems like people have had great things to say and great experience with the standard studs. I also know that there are apparently stronger options then the 625s, but arent "off the shelf".

 

[jckleewein]

I understand. That is the same thing I was thinking. I hate doing the same work twice. That's the reason why I went ahead and purchased the 625, but it sounds like it might not be a good ideal to use these head studs since the block is already assembled.

 

[TrentNell]

What John posted is the absolute truth , and is 100% the proper way to do it , but alot of poeple have gotten away with putting studs in with out doing a torque plate / hone I am one of them, but I do believe you give up some power as a result of the bore not sealing as well and there is a chance of studs higher torque spec, deforming the cylinder wall, and making the cylinder wall contact the piston skirt. So in short there is no free lunch and make decisions accordingly because it is not with out risk . But anyone ( no offense intended ) who thinks they will only build a motor once, or it will never fail if you through enough money at it , or it will never have to come back out is either (A) never going to push it hard or (B) hasn't followed the track record of built motors failing.

 

[JOHNBOY]

Not to hijack the thread, there seems to be a lot of people out there who replaces the head studs without re-boring the block. Right or wrong, how many trucks have had failures for not boring the block with the head studs in place? The 625 head studs require 25 more lbs. of torque then the standard ARP head studs. Do you think the 25 more lbs. is really going to deform the cylinder? Sorry for the dumb question.

What I found out long ago when people where trying to find answers for why pistons crack. Was that when you asked many that split pistons had recently installed head studs. Now most everyone did not connect the dots. I did not at first. It was Stingpuller that clued me in. I did some research and testing. What I found shocked me. I used my bore gage to check the bore for size and roundness with the head on by measuring from the bottom with no piston, rod or crank in the way. I then changed out the bolts for studs and rechecked. I found the bore had distorted between .004-.0045. This is with plain studs. As there not 625s or 14mms at the time. Only 25 ftlbs could be alot or a little. Remember the 625 is a good bit stronger so even at the same torque you can have even more distortion.

What John posted is the absolute truth , and is 100% the proper way to do it , but alot of poeple have gotten away with putting studs in with out doing a torque plate / hone I am one of them, but I do believe you give up some power as a result of the bore not sealing as well and there is a chance of studs higher torque spec, deforming the cylinder wall, and making the cylinder wall contact the piston skirt. So in short there is no free lunch and make decisions accordingly because it is not with out risk . But anyone ( no offense intended ) who thinks they will only build a motor once, or it will never fail if you through enough money at it , or it will never have to come back out is either (A) never going to push it hard or (B) hasn't followed the track record of built motors failing.

Right on Trent. I have pulled my motor more than I like to admit. Part of the game.