Depends on the shop. My shop charges 10 to recondition a rod. If the piston is attached, it's 17 per rod.... Every shop is different.

GO TO A REPUTABLE SHOP. I had 2 separate machine shops do my work. My rod bolt install I had gone to the better more expensive shop.

For my crank polish and cam bearing install, I went to a shop that isn't quite as regarded but for those services I was comfortable in having them perform the work.

I saved $50 by going to them and according to plastigauge he did a great job on the crank, and I could see my cam bearings were done right. That's a simple job to do.

As far as doing the rods, I think I made a wise move going to the better shop. The guy there is awesome, works fast, is honest and straight up, etc... And that's what you want. Anything that pertains to the internals like balancing, rod work, etc... you don't want to go cheap. Crank polish and cam bearing is easy work.

My guy weighed each rod/piston, measured everything, honed the ends, polished the pin end of the rod and the pin, bead blasted and etched in the cylinder numbers. All those little extra's are things you want. I would bet there are shops out there who do not do before and after measurements. I like when a guy does those things.

 

Torque/Angle is based on math (and theoretically perfect world) The reason for starting with a low torque number to make sure the bolt/nut are seated, but not stretched. If the amount of desired stretch is known, and the threads per inch are known, then the angle required to reach the desired stretch can (theoretically) be calculated.

Consider the 3/8-24 bolt:
1 full thread moves the bolt .0417"
55 degrees is 6.5454 revolutions
In theory, this would stretch the bolt .0064", so I would assume this is what was determined to be the optimum amount of stretch.

There's more about bolt stretch here:
http://performanceenginetech.com/con...tch-vs-torque/

 

I don't want to split hairs on price. I paid $50 for ARP's several years ago when I did a 396 build. I see today Thunder Racing has them for $62.99. In my book that's close enough.

Secondly the rods do NOT need to be reconditioned. Yes factory piston pins are press fit, and the connecting rod bolts are interference fit. They all need to be pressed out. This is done quite easily with a press and resting anvil. A piston or rod should never break in this process if done correctly.

 

At this point, without more info on your build, and who's doing it...it's hard to give you specific advice. At first it sounded like you're already at the point of reassembly. Please list, what all you're replacing, what you're replacing it with, and who's doing it (a shop, or yourself).

2 Key things you needed to keep in order...what caps belong to what rods, and what cylinder they belong to. The factory rod caps are not perfectly symmetrical, and are labeled such you can decipher which way to place them. On one side of the rod end-cap there's numbers cast by the factory, the other is a letter. There's also a flatter somewhat sharp casting edge on only one side of the rod.

Again, most of your questions have been answered by very reputable sources, such as Shoebox, Karl, and Machinist.

Connecting rod bolts are not to my knowledge TTY. Karl says they're reusable, and I believe him. Personally, like I said, they're so inexpensive I'd replace them; they are wear related items, from a standpoint of stress-related fatigue.

If you do replace the bolts, they do need to be pressed out. If you don't have proper tools, or aren't comfortable doing that yourself, then don't. Banging them out risks distorting the rod. But this goes back to, if you're doing all this work yourself, or if you're using a shop...and what all you're having done.

 

It isn't splitting hairs - it's a fact that when ARP rod bolts are installed, the rods need to be honed - you should not give bad advice.

And according to every machinist in my area, it is common for them to break. Perhaps the machinists in the Detroit area suck. I went to the most recommended shop in my area which has a phenomenal reputation among racers and he broke one. He must suck if it is done quite easily as you say.

Please don't tell people to have ARP bolts installed and not have their rods reconditioned - that's idiotic. For that matter, try finding a shop would will just install them and not tell you that they need to be reconditioned. Unless that's just the bogus shops in my area who break pistons.

 

ARP instructions call for "re-sizing" of the rod anytime rod bolts are replaced. This eludes to the possibility of the rod distorting during removal and re-installation of bolts. It's arguably a good idea to re-size or recondition rods during a rebuild even if bolts aren't being replaced; due to the stresses the rod sees. With that said, if this is a budget build and the guy is reusing stock components; you can get away with it if you're careful. Now, if the reason for the rebuild is he spun a connecting rod bearing, then YES re-sizing would be necessary. If that's not the case, you can definitely get away without re-sizing or reconditioning of the rods. I believe it's Katech who makes rod bolts whose instructions state no re-sizing or reconditioning is required.

 

So you are recommending he install ARP rod bolts without resizing his rods? Yes it's katech who does make bolts that do not require resizing, but this convo was about ARP rod bolts. You said you'd pay the $50 for the ARP's for cheap peace of mind and I said the rods would have to be reconditioned so it isn't quite as cheap as just buying the bolts. Now you are saying you can install them and not resize the rods? I have never heard this and I can't understand why you are trying to defend your stance. You spoke without proper knowledge, and now you googled and are trying to backtrack. If he installs those rod bolts and puts it back together without resizing it's going to break again.

Why even recommend putting in ARP if you're not going to do the necessary resizing? He'd be better off just reusing his stock nuts and bolts. I really can't understand your stance and why you are defending it, it is bad advice.

You're looking at over $200 to have ARP rod bolts installed and yes, contrary to what AmericanMuscle is saying, pistons do break in some cases so that is a risk. That being said, if you plan on upgrading your cam and spinning your engine higher, then I would definitely get this done.

Do NOT just put the ARP studs in without resizing the rods, that just makes no sense. If you can't afford resizing then just stick with the stock rod bolts.

 

The issue with ARP bolts is that they don't stretch the same way the stock hardware does. I thunk the correct way to use them is the install the hardware, tighten using a bolt stretch gauge and then measure the roundness of the big end. Odds are they'll have to be machined to get back to specification..

 

That's another thing my machinist did.... He stretched the bolts for me and told me what to torque them to. I think he said to torque them to what ARP said on the sheet.

Machining the rods is the only way to go after having the bolts installed.

 

This is true. The purpose of the ARP bolt is to use a better grade of material, that, when properly stretched, has a much higher clamping force. The issue is that the higher clamping force distorts the bores, requiring grinding the mating faces, and honing the rod back to it's proper bore size and roundness.

 

Exactly right.

The rod doesn't get stressed by knocking out the old bolts and putting in the new ones, it's the additional clamp load being applied that distorts the bore of the rod and makes it out of round. I can even oval the rod by stretching the bolt to the bottom of the spec and sizing it, then stretching the bolt to the top end of the spec...every little thing you do matters.

It's my understanding that the Katech rod bolts for the LS motors don't require resizing because they don't apply extra clamp load, they're just stronger, we never use them - just throw the weak cracked cap rods in the metal bin and start over.