Has anyone used newer stock rod bolts (2000 and up) do these bolts make your rod out of round like arp and have you had problems

 

Sorry, but why would ARP bolts make rod caps out of round? The bolt is the same dimensionally as stock, sooo....

I only use ARP when building new or rebuilding engines and have never had an issue. This includes engines making over 1200hp NA.

 

I have seen a couple of threads saying that ARP has more clamping force so it puts extra stress on the cap making it 2 or 3 thousands out of round I'm looking for longevity in the motor that's why I ask

 

The ARP material is a higher grade steel. It's tightens to a higher clamping load than the stock rod bolts.

 

Yes it is, but torque is torque no matter the strength of the bolt. Now if you tighten to rod bolt stretch then it would end up a higher torque with the ARP due to it taking more to get the same amount of stretch.

But if using torque there would be zero difference that the rod cap will see.

 

So what torque do you apply to stock rod bolts? Last I checked it was an angle value.

Also, "torque is torque" is not really true. There are other variables that will make two bolts torqued to the same value have different clamping loads.

 

Never have built a Gen3 or newer engine, but I am about to. I did know that they are set by angle, but I completely disagree with GM's infinite wisdom with this method. Again, torque is torque no matter how hard or soft the bolts are. Not every bolt will be the same as far as hardness so neither the rod stretch nor the angle setting is truely accurate. You end up with different torque on the bolts. I am personally going to use ARP bolts for the build. I will be using the angle method with stock bolts. After set, check to find the torque on the bolt and then using the ARP bolts set to that torque. Not by angle or stretch. We will see how it works. I think it should be better than using angle which cant be very accurate.

Yes, there can be very small differences when using torque methods. The threads not being perfect, the lube used on the threads ect, ect. But I feel its a better way to set anything up. Hasn't done me wrong yet.

 

Are you talking new GM bolts? If so I have put the newer bolts in (2001 ls6 is what I ordered) and put it all back together with fresh bearings, and that Guy is hard on his
car, stock rotating assm. ls6 intake and headers.
I have read where people take 1 bolt out at a time, torque that new one in, then do the
other, personally I don't have much faith in that method, but that is just me, I'm the
guy that pulls an engine out to fix a oil leak, if it's not a real simple fix in the vehicle.
My .02

 

GM's "infinite wisdom" comes from their almost infinite budget and resources to test such things. The TTA methods are indisputably more accurate and consistent.

Just what is the point of ARP bolts if you only tighten them to the same torque as the stock bolts?

 

Unless every single bolt you are using has the EXACT same strength and hardness you are not torqing them all the same amount. And its almost impossible to guarantee that every bolt is exactly the same. That makes it disputable. Using the torque method, they are all the same no matter the individual hardness or strength. The rod caps only see the amount of torque placed on them, they have no clue what bolt you are using. Using the angle method could mean lbs of difference between the 2 sides of the cap.

The matter of using ARP vs. Stock bolts is the tensile strength of the bolt. It has nothing to do with torque. ARP is stronger than stock, period. They have less failure rates, period. I have broken more than my share of rod bolts and 99% of the were stock due to building budget minded stock car engines. About 400 to 450hp with a 2bbl carb. When you build NA engines making 1200+hp and then spray another 7-900 to it as we ran in our drag cars, you don't take chances with stock parts. Any stock parts. Build a stock or lower HP engine then sure, anything can work.

We will agree to disagree on this topic.

 

Where did this even come from? You torque the bolts down to spec and go from there. I've never heard anyone having complaints of rod ENDS going out of round. The most I've ever heard is the rod bearings go out of round when changing bolts. And that's usually because they weren't changed. Rule of thumb is to change rod bearings if changing bolts. Loads of people try and cheat there way out of swapping out bearings while doing this. Naturally when pulling the torque out of a rod end it separates the bearing from the crank allowing it to flex that few thou causing the egg shape.
And torque is torque. You don't use the same bolt stretch measurements as GM with ARP anyway.
Also, the GM bolts ARE the weak link in the bottom of these motors anyway when it comes to making power. Why risk it?

 

Taxman, I would not recommend under-torquing the bolt to avoid bore distortion. These bolt's torque values have a directly related bolt stretch. This stretch is crucial to the bolt being able to maintain its clamping load.

As for the torque to angle, the thought process is: as the torque load increases, frictional variables increase. These frictional variables can cause a torque wrench to read fully torqued when it has not yet reached its optimal stretch. in the field these variables can be a problem.

In the case of a rod bolt, there is a process that I think is superior to both torque specs and TTA, that is rod bolt stretch. Professional engine builders use a combination of torque specs and rod bolt stretch measured with a special micrometer to assure the bolt has and will maintain its proper clamping force in all conditions.

In general, the aftermarket bolts like the ARP will have a higher clamping load. This additional clamping load can and does distort the bore concentricity.

If you want to do it right, install the rod bolts with the above method then check the rod bore for size and roundness and resize the rods as needed. This is how the pros do it for a reason.

 

00SlvrSS, yep. I was basically asking the same thing, just short hand. Had never heard of a bolt causing the issue questioned.

Speedtiger. I wouldn't be trying to under-torque at all. I do not feel that it causes any bore issues with the rods when using ARP bolts. That was the first OP question.

I have had engines built by torque and stretch. Both work fine with neither one seeming to be any stronger or reliable than the other. Both have failures. My point is simple. First we torqued bolts. Then the better option was to use stretch. Now the better option is to use angle. And in reality the torque version we used for 100 years worked just fine. I do not see any data that verifies that the next 2 types were any better. And I mean real world data, meaning I use it myself or have first hand knowledge. Its the job of the designers and engineers to make it look better or it would never sell.

And just like you, you believe that the stretch method is better than the other 2, even though GM swears on the bible that the TTA method is better because they spent millions to engineer and prove it. I feel torque is better.

I had a Reher-Morrison 565ci 1000hp NA engine in my dragster. Each year it was freshened up. I could spend 3-6000.00 on the rebuild to be done by Reher-Morrison depending on the parts needed, which used the stretch method. Or I can spend 1000.00 or less and do it myself using the torque method. I had no higher failure rate either way. I actually never had the engine fail. So neither method was proven better. It just proved to me that my way with using torque is just as good as the new ways.

I guess I am still sort of old school. They just haven't proven anything to me personally. I'll continue to make sure the threads are all clean, use the right lubricant, ARP bolts, a quality torque wrench and go to town.

On this first LS based build, I will test the angle method. That was already the plan. But I am also going to check what the torque is on every bolt.

 

Use whatever method you wish to torque your bolts, but I am here to tell you that increasing torque specs (increasing load) on fasteners does, beyond a shadow of a doubt, distort the bores of a connecting rod as well as main journal saddles in a block. You can easily prove it to yourself by torquing the bolts to different amounts and then radially measuring these bores with a high accuracy bore gauge like the Sunnen units used by machine shops.

 

I agree 100%. But again, that's not the question by the OP. He asked about the bolt itself causing an issue. It doesn't. I never said that more torque wouldn't cause a change. Sure it can. I was only stating that an ARP bolt set to the same rate as a stock bolt will not cause an issue with the rod circle. ( after reading his post again I made a correction below to clear up my statements, I can see where there is confusion to my statements above )

The caps are designed to have a specific pressure applied to them. The cap only sees that pressure. It has no idea of the hardness or softness of the bolt that installed in it. 100lbs is 100lbs no matter the bolt used. The cap couldn't care less what bolt is used.

My other point was that ARP is stronger than stock. That's all. Then this whole torque thing popped up.

 

Now the answer to this question is, yes it would have more clamping force than a stock bolt due to the tensile strength being higher than a stock bolt. It stretches less. And when using the angle method yes, this can happen.

But that's where I like torque method better than angle. Doesn't matter what bolt is used. And this is how I am making a statement. Using torque, not angle.

 

Do you have the engineering data on both the stock bolt and the ARP bolt to know that they have the same clamping force using their respective torque methods?

 

So my build I want to reuse my rods during this rebuild so if I could get this torque that you talk about it would be great because the tta method goes to a certain torque and then torque it more so I don't know what the end result would be but the original question was if I could use the ls6 bolt because it has less of a failure rate from my understanding I am looking for longevity mostly for my build now I have been contemplating just getting new rods with the stock pistons to be able to just set this aside

 

If you use a fancy SnapOn torque angle wrench it will tell you what the torque was when you reached the correct angle.

The angle method takes the friction out of the equation. Seems the better method to me.

Try this, put one bolt in dry, one lubed with this fancy wrench and see what the torque difference is.

As far as every bolt being exactly the same, I'd bet they are pretty damn consistent.

I reused the stock bolts and bearings in my SBE turbo car as many folks do. If it was all messed up due to bearings out of round and weakened bolts etc, it would have died long ago. Yet it's survived at 800+ WHP and 7200 rpm for 80 passes now.

I'll be taking it apart for upgrades and more hp for next year. I'll see how it all looks.

Ron

 

Yes and no. ARP bolts have a higher tensile, and inherently a higher yield, but that alone doesn't make it better. You don't just throw them in, torque them the same as the old OEM rod bolt (like Gen I SBC) and expect them to perform better. The higher yield allows you to increase the torque/stretch/angle/whatever and increase the clamping load on the rod. This is the real benefit of an ARP bolt. This oftentimes causes the bore distortion the OP is talking about, but it's need to counteract the increased loads trying to tear the rod apart at higher engine speeds.

I agree. I have that fancy $450 Snap On torque wrench. I haven't used it on OEM rod bolts yet, but on the OEM mains I have seen about 10ft-lbs difference between the same bolts (inner vs outer) at the same angle.