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Discussion Starter · #1 ·
Hello guys I have a few questions about ARP head studs and main studs for a small block chevy dart shp block.I got a call from my machine shop the other day and they was asking me about my clearances on what I was wanting and what type of oil pump I was using and what type of oil pan etc and then after I told them what I had and that I was not using a 25 percent high volume oil pump , but an oil pump more then stock, which I mentioned was a Melling 10552ST oil pump that was only 10 percent more volume then stock, they then knew what I was looking for in clearances on the rods which I said around the tighter side but not too tight and they are looking at .023 average, which is what I had done on my current build and hold pressure of 60 psi cruising.

After that was all asked and done they asked on my mains and I had included my ARP main studs that is for the dart small chevy shp block so they can check the align bore and they asked me what I wanted them torqued at and I stated what ever the instructions said with the ARP stud kit and it calls for 80 ftbls on the 7/16 inner studs and 45 ftlbs on the 3/8 splayed studs on the three inner mains. That is with there ultra lube for torque specs. I know on a stock oem specs they call for 70 ftlbs on the inner bolts and 65 on the outer on a 4 bolt main and for 40 ftlbs on the 3/8 bolts.

I have read about how the ARP ultra lube has a lot less friction vs other methods for lube such as using moly lube or 30 weight oil for torquing down fasteners etc and I know studs call for more torque vs bolts, at least that is what I have read on some things in the past. I am also going to be reusing my ARP head studs with my aluminum heads and they call for a whopping 80 ftlbs on there head studs using the ARP lube. I have read about folks trying to get to that torque spec and the ended up ripping out the threads from there block and some recommend not torquing the head studs or even the main studs that tight.

For the main studs I read it distorts the main cap and can throw off the bearing clearances too much and on the head studs, 80 ftlbs can be to much and pull the threads out a lot of times. I know the ARP lube creates less friction then other lubes so why should it have a way higher torque value vs something else? If it creates less friction and has a closer value for clamping force then why they higher numbers they are calling for? I know the ARP studs are way stronger then OEM fasteners which are what normal factory specs are called for but on the ARP 3/8 bolts the torque is not much difference on the mains and by only 5 ftlbs, but is a ten pound difference on the 7/16 bolts and on the head studs its a whopping 15 pounds difference.

When my current dart shp build was done I was with my Father and he used the red assembly lube that is the sticky stuff that you use on your bearings and stuff on the ARP main studs and I can't remember what the 7/16 bolts were torqued too but it was either 75 or 80 ftlbs and the outer 3/8 was 45 ftlbs and never had any problems with using that stuff. Now onto the heads I don't know what he used as I was not there when he did that part.

I am just putting that there for past use. My concerns is when I get my stuff back from the machine shop and stuff and once it comes time to put thing together I am a little worried about torquing my head studs at 80 ftlbs using ARP ultra lube and risking stripping out my threads on my block and don't want to have to give any more clamping force then what is necessary for the head studs and then on the mains I am concerned about going to 80 ftlbs again on those after the shop just did that to check the main clearances. If I were to only try 75 ftlbs on the main studs and only 70 ftlbs on the head studs would that hurt anything or would it not be enough?

I understand the differences on torque values and on the thread pitch of the fastener being used can create differences on what is needed for proper torque but I don't like how for ARP head bolts for small chevy they only call for 70 ftlbs which seems good but on there studs they call for 80 ftbls which seems quite a bit to me. Dart on there instructions for there bolts that come with the block call for 65 on the 7/16 boltmain s and 35 on the 3/8 bolts. I know studs take more torque but how much is to much with risk of messing things up? I know ARP has there reasons but I also know the oem folks have there reasons as well for there torque specs.

I just want to not risk anything on both ends on not being to much torque and risk ripping out threads or creating to much distortion or not enough clamping force. Hope some of you guys who have more experience can shed some light on this topic and what would be the best route I should take to be safe in all forms before this build is done soon. Should I just torque the head studs at 75 ftlbs and the mains at 75 ftlbs and the outer 3/8 bolts still at 45 ftlbs using the ARP ultra lube to be safe and would it be fine at those specs?

I do know about making sure the washer that goes underneath the head stud nut needs to sometimes have it skinned across a piece of sand paper so it will grip the more slippery aluminum head to help to not over torque the stud as the aluminum surface can be so smooth it can make the washer spin around while trying to torque and thus needing to much torque to get the right amount of friction for said torque value and can make you end up pulling the threads out of the block. I know there are some arguments among some builders on this topic of proper amount of torque and ARP calling for a little to much.

Thanks guys and sorry for all the stuff but want to calm my head down and be able to know what to do when the time comes with out second guessing.
 

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This is always worrisome to me, as I like so many others have found that the extra torque of ARP spec’s occasionally pull the casting’s threads out. I find that this is a bigger probability of occurrence with bolts than studs. Bolts put a more complicated set of loads on the casting where they are introducing a twisting moment as well as pulling which results in a shear moment on the thread, and no matter how fantastic your nodular iron, or mild steel main cap and it’s bolt or stud is, in the end all the loads both installation and operating are carried on those cast iron threads

At least with nuts on studs most of the torsional moments are between the nut and the upper stud body rather than the threads in the casting.

The down side of better steel and or fancier heat treatments to a fastener is there has to be more tensile force to get that material into its band of elastic deformation sufficient far above operating loads that they will not allow the clamping force to loosen by working the fastener further into its elastic region. Not talking TTY’s here, that’s a different breed.

I think before running racer strength fasteners like ARP and other brands the builder needs to consider if the application warrants such fasteners versus approaching them as bragging rights where they aren’t needed.

Bogie
 

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Discussion Starter · #3 ·
Mine is not for bragging rights its just I like extra insurance on things and when I have a build done I like strong fasteners that I can reuse with out having new stuff. I have ARP fasteners all over my engine from the oil pan to the mains and also on the cylinder heads. I am thinking about just going to 75 on the 7/16 bolts on the mains and the heads and call it a day and would not think that would be too loose and it should provide enough clamping force to not get loose but what do I know a I am not an engineer like the folks at ARP that make there fasteners.

I use factory specs on there bolts on other areas and don't have issues but its not overly critical stuff like main and head bolt stuff or in my case using studs. I like studs for the lesser chance of stripping out the threads in the block as I had that happen once and ever since I have used studs with great results and no problems but this is also with new blocks as well and not ones that have had thousands of heat cycles on them. What would you do Boogie?
 

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Given you’re using a Dart block and that block hasn’t been in service for 20 years or hasn’t been raced as a steady diet I wouldn’t be concerned about ARP’s torque specs. if this was a 20 to 65 year old production block I’d use factory fasteners or something from ProComp that wouldn‘t stress the cast threads so much when pulled to their specs.

Bogie
 

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What was the reason for discarding the Dart supplied fasteners??

They are made by A1 and are as good or better than ARP unless something has changed in the last couple of years
 

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Discussion Starter · #7 ·
I honestly never looked at the bolts that come on the mains of the Dart shp block but I think they are like ARP but I like using studs where ever I can to help save on threads and less chance of things getting pulled off. I have ARP studs on my oil pan and my oil pump and also on my heads and then will be getting some ARP studs for my carburetor. I just like using them more for better insurance and that is just my preference. I know it seems like overkill but that is how I like to do my builds regardless of how I run them.
 

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Dart makes good fasteners.
The ARP spec is fine on the Dart caps with their spec juice.
Make sure the stud is screwed in by hand untill the bottoms out and unscrew it a 1/4 turn. Proceed a normal.
 

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Discussion Starter · #9 ·
Ditto I had that done on the last build, my Father turned in the studs all the way and then backed them back out about a 1/4 of a turn or so and then I torqued them down in three steps to the final torque they recommended.
 

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What was the reason for discarding the Dart supplied fasteners??

They are made by A1 and are as good or better than ARP unless something has changed in the last couple of years
This is the closest thing to my question the search turned up. Thanks E32. Holy thread revival!!

My question is the Dart specs seem a little light to me. Will they be tight enough at #65 for the 7/16 mains, and #35 for the outer 3/8 bolts?
I am using Darts hardware on the SHP Block, and these are what they call for...
 

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Discussion Starter · #11 · (Edited)
I did not go by Dart's specs on the torque values. I went with ARP studs and I torqued the 7/16 to either 70 or 75 at the most and the outer 3/8 to 45 with arp lube on them studs. I also made sure the studs were not all the way snugged into the block as on ARP they state to make sure the studs are at least a half a turn out so they are not tightened up to where the middle non threaded part of the stud will stop it from turning during the torque sequence as it can cause a crack in the main webbing area. I put them in and then back them out a full turn and mark them so I can tell if they turn some after I torque them down. Some folks will put a tiny ball bearing in the hole to not let the stud bottom out.

I think it was 75 on the 7/16 bolts and I was in a hurry with things and my Father was also helping put things together so he was spinning on fasteners and also used the torque wrench as he torqued them first and I did the final sweep and he said the 75 was only about a 1/16 of a turn difference from 70 to 75 but this was back during the summer and I always write down what I torque all my stuff at and also my clearances and other things and I do know for sure I did the side studs at 45 and I have had it running just recently and also my machine shop when I had them to check the line bore with the studs they also torqued the mains at 70 or 75 and 45 on the side and I followed what they did. I just don't have my paperwork in front of me without having to dig it out.

Stock specs on a small block chevy are only 70 on the 7/16 bolts and the studs always take more torque but I did not do 80 like ARP calls for on there mains and cylinder head studs as I have seen some folks have there threads ripped out or the mains were pulled to tight and it affected the proper clearances on the bearings.

I did my last Dart 377 build the same way and ran it three years and that thing looked brand new when I sold it back in the summer. The arp lube is so slippery I think the 80 is a little much and have seen folks asked arp about it and they stated they could do 75 and it would be fine. With using aluminum heads I had the head studs done either 70 or 75 but my Dad did those as I was not with him at the time he finished up the build.

I went with what the machine shop torqued the mains at so I know the proper clearances will be good and also on the head studs as they used the torque plate on the top with my studs to give it the final hone and this shop has built $10,000 plus builds and has over 40 plus years in doing stuff and is a performance oriented shop and not just a run of the mill type. Over all my years I only had one time that someone did a botch job a set of heads I had done with them but that was all. A communication error happened and left me with a set of boat anchors but they owned up to it.
 

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Ideally, when you switch fasteners, use the fasters spec and confirm the bores are still round. An aftermarket block is stiffer so it's probably not going to change things much, check it anyway, re-machine to suit.
 

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Ideally, when you switch fasteners, use the fasters spec and confirm the bores are still round. An aftermarket block is stiffer so it's probably not going to change things much, check it anyway, re-machine to suit.
Sorry for the confusion.
This was the closest thing I could find to my problem I'm having. I'm going to start my own thread with a specific question .
Just to be clear. I am using an s h p block, with the original Fasteners coming straight from Dart .
 

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OK. I misread that.
If it's a new block, It'll need checked anyway as they don't come from DART ready to assemble and will likely need something but I follow what DART says. They know more than me.
 

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Discussion Starter · #17 ·
If I re read the last few comments then as far as if I did not use ARP studs in the bottom then I would have went with what Dart had recommended on there bolts as far as torque goes with what ever lube they recommend. Even if a new block you will have to get things done as I had everything checked on it as you just can't risk it. I had done to it what you normally would do with a stock block.

I had the works done to mine on every last fine detail as when doing any build if you can have it done then its always good insurance.
 
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