Sort of a strange question about main bolts

[Calan]

My machine shop accidently swapped the main bolt and stud for the oil strainer on my short block (they didn't have the front case, so it was an honest mistake).

As I was swapping and retorquing them, it dawned on me that I had really wanted to switch to ARP main bolts, but I let it fall through the cracks at some point during the parts ordering and machine work. So my question is...

Now that all the machine work has been done and the rotating assembly completed (as well as a good chunk of the timing components, etc)..... could I just swap out the stock main bolts one at a time for ARPs, without having to worry about any of the bearings shifting or having to disassemble it and take it back to the machine shop to have the caps align honed?

If so, what would be the best way to do it? Replace and retorque them one at a time, or replace one at a time "hand tight", and then retorque them all in sequence?

I plan on this motor lasting a while and want to do it right. If the stock bolts are good for 550-600 HP, I'm fine. Otherwise I'd like to swap them out.

.oO Can't believe I let that slip.... must be getting old

 

[tsiAWD91x]

i woudlnt technically your shoudl have your block line bored if you go with the ARP studs, as i was in the same spot your were at one point. the stock bolts should be fine to 550hp bro, no worries. the rod bolts now are a diff story

 

[Calan]

I was thinking that since the caps have clearance around the bolts, it shouldn't change the alignment; just more clamping force. I don't think the caps and bearings would move if I replaced the bolts one at a time, due to the way the caps lock into the block. But I dunno....

Rod bolts are the ones that came with the new Eagle rods.

 

[lacroixdp]

I've been given mixed opinions from this back in the day. One of my machinists swore up and down that you needed to since it changed the crimping force on the caps. The other one I used argued that as long as you stuck with stock torque figures it wasn't necessary. I ended up never doing it and didn't run into any problems. Not exactly the rock-solid answer you were looking for, but I thought I'd offer it up anyways

 

[Calan]

Yeah... I just can't see the main caps flexing any more. They are pretty substantial, and it's not like there is 100 lbs. of torque on the bolts. (I'm not sure on the ARP's, but stock is around 50 ft. lbs.)

I really hate to take it back apart and haul it to the machine shop (in fact..I won't , but I'd also like the peace of mind with the ARP's instead of the old stock bolts if it's not a big deal.

I hate these spots you get into with rebuilds...like should I replace my Mitsu timing belt that only has 3k miles on it just because...even though money is tight? There is another tough one

 

[Clutch GSX]

No need to aline bore with new studs. Unless of course your journals are out of line. Stronger studs don't warp your journals. To install ARPs, you hand tighten the studs then tighten them a little more with a wrench. Then torque the bolts how it says in the service manual to the torque specs that ARP gives you. Make sure you use lots of lube.

 

[HIGHPSI4]

I agree, no need to line bore the mains, just a waste of money in this situation. The ARP's will not mess up the caps.

 

[rush2252]

Mr. Perfectionist is starting to get a little ancy!

Im ready to come up and see the progress this weekend. Maybe it will give me a more positive outlook on DSMs in general. Mine is making me sick to my stomach


Im ready to hear this bad boy run!

 

[Calan]

Mr. Perfectionist is starting to get a little ancy!

I resemble that remark.

I just like to do things right, and do it once. Maybe I'm really just lazy.

*****************

I've never looked at the ARP main studs. Will I need to pull the caps, or will they thread in without the cap/bearing coming off the crank?

BTW - Does anyone have any real-world numbers for what the stock bolts can safely hold?

 

[Clutch GSX]

You can try to put the bolts in without removing the caps but I doubt you will be able to. The bores aren't completely straight usually. If youre going over 400HP I wouldn't mess with old stock studs no matter what they "should" handle. The main journal may be the single most important area of the engine so I never like skimping in that area.

 

[Calan]

I hate being a paranoid perfectionist. Now I'm staring at my block about to bolt the head down, and wondering if the machine shop really got the deck surface smooth enough

I don't remember ever being this paranoid when I was building Chevy small blocks 20 years ago, and they always held up fine. I think it's "old" age or senility setting in...

 

[dsm-onster]

At some point you're going to have to bolt $#% up and see what will happen

But seriously. A VERY, VERY, VERY, VERY small difference makes a substancial distortion when it comes to rod bolts and main bolts. If you swap stock rod bolts for arp rod bolts it is HIGHLY recommended to line hone the rods. How are main bolts that much different?

It's good engine building to line hone everything if swapping old stock for just new stock. Much less bolts that clamp stronger. . . I don't think youre that paranoid. You're simply thorough. Dont snuff your strength out as a weakness.

With that said the stock main bolts have been good for, what, 800-1000hp. I'm sure you'd be fine for your goal not to worry about arp main studs. I really htink they are a waste of money.

 

[Team Addiction]

To answer the original question yes you can swap them one at a time it will work fine. There has been some talk of CW with ARPs if the block was not line honed. Personally I dont buy it but.......
Im under the impression that Shep is using stock main bolts so hey who knows?!
Myself I used ARP main studs and changed them out one at a time because they forgot

 

[Calan]

At some point you're going to have to bolt $#% up and see what will happen

Yeah I know... if I had everything sitting in front of me ready to go instead of waiting on funds/parts, I don't think I would have given it a second thought.

I don't think youre that paranoid. You're simply thorough. Dont snuff your strength out as a weakness.

But there is a fine line between "attention to detail" and "anal retentive"

With that said the stock main bolts have been good for, what, 800-1000hp. I'm sure you'd be fine for your goal not to worry about arp main studs. I really htink they are a waste of money.

You talked me into it (was leaning this way anyway). The stock bolts are staying, I'm gonna continue with the build, and one of these days I'll drive the shit out of it until it pops

Thanks Matt