ARP main stud ?

do you guys screw them in hand tight or do you torque them before you put the main caps on and then torque the main caps? And if so how much torque on the studs in the block and the torque on mains?

I don't use them I feel the factory Bolts are better.....

the Coug wrote:I don't use them I feel the factory Bolts are better.....

Do tell.......

bigjohn2007 wrote:do you guys screw them in hand tight or do you torque them before you put the main caps on and then torque the main caps? And if so how much torque on the studs in the block and the torque on mains?

That all depends upon your intentions for the studs.
1. Installing them the correct way as to an extension of the block
2. To install 'em simply as a replacement for the bolts.

The 2nd is almost useless so, I don't even bother.

First tap the holes with a bottoming tap ... clean the threads really clean ... install the studs with Loctite till finger tight then back-off 1/4 turn ... install the caps immediately and torque to specs. It will be ready to use after the Locktite sets-up.

I was told by a Hot Street racer that you also have to line hone the block when changing from bolts to studs being that it spreads the load on the cap differently. He blamed the bearing failure he had on this. It was a dynoed Kuntz smallblock , N/A 400+ or - inch motor. He decided he wanted to stud the bottom end before the season and just swapped them out and ended up having some hung bearings.

Whats your thoughts on this Randy?

Travis

you need to check it for sure, may or may not need to be honed.

I had to have a CJ block align-honed after changing to studs. It was a noticeable difference.

TravisRice wrote:I was told by a Hot Street racer that you also have to line hone the block when changing from bolts to studs being that it spreads the load on the cap differently. He blamed the bearing failure he had on this. It was a dynoed Kuntz smallblock , N/A 400+ or - inch motor. He decided he wanted to stud the bottom end before the season and just swapped them out and ended up having some hung bearings.

Whats your thoughts on this Randy?

Travis

Sometimes studs it will cause a different distortion of the metal around the bolt hole than bolts will cause and sometimes it won't make any difference. Usually if the stud is incorrectly bottomed or torqued into a "non bottom tapped thread" is will have a different distortion.

Yep that's the deal........it's not that the housing bore will change....it's that it darn sure can change.

TravisRice wrote:I was told by a Hot Street racer that you also have to line hone the block when changing from bolts to studs being that it spreads the load on the cap differently. He blamed the bearing failure he had on this. It was a dynoed Kuntz smallblock , N/A 400+ or - inch motor. He decided he wanted to stud the bottom end before the season and just swapped them out and ended up having some hung bearings.

Whats your thoughts on this Randy?

Travis

That was his first problem buying a Kuntz and craft engine..... several years back a Friend bought a kuntz and Craft 408w he brought it by and something didn't look just right, so we disassembled it to check..... Hell Half the rods were in Backwards with the Chamfer butted up against the other rod, 3 pistons were if facing the wrong direction.... so we corrected the problems and rechecked everything else..... and he Raced it for several years. But everone is alowed a mistake or several I guess.....

First,
I just wanted to throw a flag up for the guy who posted the intial question. Seems that MANY a people think they can just bolt things on and down and just go with it. Thats not always the case. He was asking a question because aparently he has not dealt with this before. This really is no different than honing with a torque plate.

Next, I definatley was not bashing Jim Kuntz at all. They assembled and dynoed the engine and Charlie took it upon himself to make the switch to studs. This was a lesson learned so to speak and how I came to find out you just can't bolt things together so I am just passing it on. Now as far as Kuntz and Kraft I really can't speak for them myself, Jim on the other hand branched out on his own and did an excellent job on my current BBF cylinder heads. He also has built numerous engines from World record holding FE's to the current Hot Street car I am referencing to ................. Charlie Booze ..... 5 time world champ and his brother Brian Booze who also was a 4 time world champ in the NMCA,NMRA,and the RAM racing series. Kind of speaks for thierselves. Not disrespecting you Coug, just the way I see it from my end.

Travis

Travis I am saying if you buy one check it out.....as for the studs vs Bolts I would rather use the Bolts. if they are bad the why have the car builders use them on 100 Billion cars.... I work in an Industry where we have to have real world results, and we have found out that a course thread bolt has more tensle strength than a fine thread one has, and trust me we use them from #4 up to 2 inch plus we use alot of studs and fine on one end and course on the other..... Guess which end ALWAYS strips first, we feel it is from lack of thread contact surface area......

So at what point do you need to use the arp studs over the factory bolts?

tiger wrote:So at what point do you need to use the arp studs over the factory bolts?

Factory bolts are fine at what ever hp you desire....

stock bolts in the double D...........

richter69 wrote:stock bolts in the double D...........

right ...you mean stock A460 bolts?

138 it doesn't matter if they are A460 bolts or STD bolts they are the same.....I changed some of my A460 bolts out in favor of Factory Ford windage tray bolts.....same length as the A bolts....

tiger wrote:So at what point do you need to use the arp studs over the factory bolts?

Studs, when installed correctly, will allow more clamping force; (IF the metal it is installed into lends itself to that happening).

Years ago, we did a test with several transducers at the head gasket surface of a B.B. Chevrolet block and we found out a lot of interesting stuff. Like IF the stud, (or bolt), is a lot tougher than the block material, clamping harder with the fastener simply distorts the metal surface of the block more and SEALS less.
The entire reason to use more clamping force is to get a better seal or less cap walk and if the opposite happens the extra clamping force has FAILED to do it's job.
Now, with a main stud, it does almost no good at all if the fastener needs to be torqued past the block material thread strength in order to get that fastener stretched to the correct amount.

Just for argument purposes; a 7/16" diameter ARP stud, (not undercut), needs to be torqued to 144 foot pounds with 30 weight oil in order to get it stretched to just before yield. Ask yourself, what cast iron with a 7/16-14 thread will take that amount of torque without yielding before that stud...?

rmcomprandy wrote:

tiger wrote:So at what point do you need to use the arp studs over the factory bolts?

Studs, when installed correctly, will allow more clamping force; (IF the metal it is installed into lends itself to that happening).

Years ago, we did a test with several transducers at the head gasket surface of a B.B. Chevrolet block and we found out a lot of interesting stuff. Like IF the stud, (or bolt), is a lot tougher than the block material, clamping harder with the fastener simply distorts the metal surface of the block more and SEALS less.
The entire reason to use more clamping force is to get a better seal or less cap walk and if the opposite happens the extra clamping force has FAILED to do it's job.
Now, with a main stud, it does almost no good at all if the fastener needs to be torqued past the block material thread strength in order to get that fastener stretched to the correct amount.

Just for argument purposes; a 7/16" diameter ARP stud, (not undercut), needs to be torqued to 144 foot pounds with 30 weight oil in order to get it stretched to just before yield. Ask yourself, what cast iron with a 7/16-14 thread will take that amount of torque without yielding before that stud...?

if you use arp lube the torque will be less right

bigjohn2007 wrote:if you use arp lube the torque will be less right

Yes usually the ARP has its own torque specs

bigjohn2007 wrote:if you use arp lube the torque will be less right

It will take less torque simply because the friction on the threads is less ... the "tensile" or amount of pull on those threads IS the same.

This is just my UNprofessional opinion. I would rather use a stud because of the wear on the block threads.When you use a bolt and it starts to tighten,you are tugging on those threads as the bolt is threading in . With the studs,it is in the block and at its desired depth,and when you start torqueing the stud down you are pulling on all the threads at the same rate.jmo

bbf-falcon wrote:This is just my UNprofessional opinion. I would rather use a stud because of the wear on the block threads.When you use a bolt and it starts to tighten,you are tugging on those threads as the bolt is threading in . With the studs,it is in the block and at its desired depth,and when you start torqueing the stud down you are pulling on all the threads at the same rate.jmo

A stud which is undercut on the shank so the correct amount of stretch is reached at the normal torque value for the tensile requirement of the cast iron threads and also correctly anchored into the block threads would be best.

rmcomprandy wrote:

bbf-falcon wrote:This is just my UNprofessional opinion. I would rather use a stud because of the wear on the block threads.When you use a bolt and it starts to tighten,you are tugging on those threads as the bolt is threading in . With the studs,it is in the block and at its desired depth,and when you start torqueing the stud down you are pulling on all the threads at the same rate.jmo

A stud which is undercut on the shank so the correct amount of stretch is reached at the normal torque value for the tensile requirement of the cast iron threads and also correctly anchored into the block threads would be best.

That's kinda what I was thinking there Randy..