Al2011

I just goy my block align honed and bearing clearances blue printed for the mains and rods. On the blueprint card it states they torqued the main cap nuts to 95ft lbs with ARP lube. I called him back to verify this is correct he said it is and 110 is with motor oil. I'm confused. Will I have a problem if I torque them to 110? Or should I follow their advice. The shop is a reputable race shop. What should I do? please help. graetly appreciated,.

442rocketdave

I think that is correct and I have the arp studs in my block and I know its a different value of torque with oil over the arp lube. I called ARP and they told me to only torque them 95lbs with their special lube as the bolt stretches better with their lube. I would call them to double check. The one thing I do know is that you cannot torque them the same as the bolts it will always be less with the studs. I hope this helps

MDchanic

Torque then to the ARP specs.

No more, no less.

- Eric

cutlassefi

Not sure why they told you that.
My card says 100 with their lube and 130 with 30wt oil.
The reason is not because they stretch differently, in theory you need a certain amount of stretch anyway.
The reason is thread friction, their lube will have a significantly different effect than plain motor oil.
And when using studs over bolts they'll pull differently mainly because you have two load areas, the stud/nut area and the threads into the block.

MDchanic

... And just to be clear:

All bolts (and screws) stretch (get longer) as you tighten them.
The idea is that you get a certain amount of elastic stretch (which will return to its previous dimensions) before the metal loses its elasticity and stays in its longer state (which is just before it starts to strip or break).

When torquing (or tightening) fasteners, you are looking to get the best elastic stretch you can get, but not beyond that (except in the single-use torque-to-yield fasteners, where you do actually stretch them beyond their ability to stretch back).

A lubricant lubricates the "top" edge of the screw's threads as it bears against the "bottom" edge of the block's threads, making it easier to turn.
Since it is easier to turn (requires less force or torque), you torque to a lower torque reading to get the same amount of rotation. Since a certain amount of rotation equals a certain amount of stretch, you get the same stretch with less torque, which is why the torque requirements will be different with different lubricants.

As I (and Mark) said: Torque to the specification supplied by ARP, and with their lubricant if at all possible. They've tested this out and know what they're doing.

- Eric

Octania

Huh... either way you have two motion areas-
1) bolt thread on block or stud thread on nut
2) bolt head on cap or nut on washer/ cap

I understood the MAIN stud vs bolt difference to be the fact that studs typically use NC threads in the block/ main item [stationary during final securing], and NF threads on the protruding end, which gets the motion during final securing. Therefore, with a bolt you are moving a steeper ramp- NC threads, whereas with NF threaded stud and nut you are moving up a less steep ramp, therefore less T is required to attain the desired tensile force and therefore stretch of fastener.


As I (and Mark) said: Torque to the specification supplied by ARP, and with their lubricant if at all possible. They've tested this out and know what they're doing.
===================
AGREED.
Rely on the advice of the folks who developed these fastener systems and tested everything and found what works and WHAT FAILS.

This assumes of course that you have advice, from folks who have tested their product and found what works...

As opposed to the Chinesium POS main studs that come with the Chinesium POS "halo girdle" for cheap on say epay. Please look at the photo of the main stud which SNAPPED OFF before 80 ft-lbs was attained [small block #4]. Note that the "instructions" came with NO CLUE as to what lube if any, or the proper torque value. Instrument was a recently calibrated Snap-on brand clicker torque wrench with a proven history of proper fastening, so I think we can rule out incorrect actual torque value.

http://www.ebay.com/itm/150646769737...84.m1555.l2649

442rocketdave

CutlassEFI, I think my advice was correct and according to every box of ARP bolts on the back is thier torque chart and for 1/2 20 the specifications are 122lbs for 30wt motor oil and 95lbs for ARP moly lube now I also called them and specifically asked them why the difference and its because they stretch differently according to the lube used. I also informed him to do what they say period. The stud has 1/2 20 theads on one end and 1/2 13 on the other where you apply the torque is on the 1/2 20 side so the specs are 95lbs with the ARP lube. I also told him to call them.

442rocketdave

So we are on the same page my studs are the 170,000 psi strength studs they make them in 190,000 and 220,000 so check which ones you have to get the right torque value. Good luck with your engine build!!

Al2011

Thanks everyone for the replies. Mine were rated 200,000 PSI. If the machinist align honed the mains with the nuts torqued to 95 ft lbs then I should be Ok torqing the nuts 110 ft lbs from what I understand without causing a problem. If I'm wrong please let me know.

http://arpinstructions.com/instructions/185-5401.pdf

http://www.summitracing.com/parts/ar...ake/oldsmobile

442rocketdave

Your fine with 110lbs with the arp lube!!! if you use 30wt motor oil go to 138lbs you will be right on the money. Glad you had it align honed otherwise you would have had trouble. Keep us informed on how you build is coming along!!

VinMichael

Didn't have my block align honed and used main studs. The assembler said the block didn't need it and said to save the money. He said that if it was a 302 or something then it may have been a problem since that's such a lighter block compared to the 455. It's not running yet so I can't attest to having problems or not, but I'm planning on everything going fine.

442rocketdave

As long as your clearances are right and your end to end play is right on and you center the thrust bearing and your crank turns over with not alot of effort you shold be ok especially if your just revving to 5500rpm. If your spinning up over 6800 then there could be problems. The problem come if when you install the studs they move the main caps and this happens but if you caps seat straight and even and everything turns smooth you should be ok.

oldsjeff

The reason for the significant lower in torque specs not only has to do with the lubricity of the applied lube, but also of the contact of the threads. ARP maintains a high thread contact (60%) while most, at best are 40%. Follow the ARP guidelines, and if your unsure of it, go to their website and download their specs.

oldsjeff

As far as your rotating assembly, line boring and proper cylinder squaring to it is essential. There should be NO drag, regardless of RPM's, and if a motor shop says "you'll be fine", than your wasting your money. Last time I heard a shop say that the fellas motor seized on him and the shop was all too ready to build him a new one. To be "just fine", in my book is an excuse for shotty craftsmanship. Do it right, spend the bux, peace of mind is a lot cheaper than a piece of motor. Question proper is this, internal balance or external? Don't mix 'em

cutlassefi

You apply it there but it pulls on it everywhere. If you follow their instructions you'll be fine.
But for best results, if your machinist did them at 95 with ARP lube then you would be best suited to do the same.

442rocketdave

Vin Michael, after rereading what you said I have to say that align honing the block is only 150 dollars and after rethinking it I would say you should go to another shop and have them align hone your block, in the old days we had cranks and motors everywhere and cheap but not today and everything cost alot and is harder to find so you would be better off having it done right and you will be alot happier. Its just to much work to have to do and the money involved for a new crank and bearings plus the machine work AGAIN. Think about it you spend that much money on a dinner date!

Milan..

110 lbs w ARP lube , Tested this many times works fine , make sure its the new style Ultra Torque lube.
And be sure to re-clean your bearings and use a bearing lube like Clevites when you assemble.

VinMichael

That's very true, the $150 was not the reason that I didn't have it done. It was because the machinist with the align hone machine said it was not necessary. I even insisted, but decided to trust what he said. After all, I dropped it off to him with the original bolts to get before and after measurements. The short block is already assembled so I feel as if it's time to continue moving forward. I get what you're saying about the diminishing availability of OEM engine parts, but there is now a huge aftermarket for cranks and rods, etc. Thanks for your input but at this point I'm ready to just roll the dice and see what happens. I'll let everyone know what happens after I get the rest of the engine together and running.

The guy who assembled the engine is also the only guy around my area with an align hone machine, at least as far as I know.

442rocketdave

In the early 70s I did it several times and I had to adjust the caps but I made it work but I was married young and did not have much money but I raced anyway! You probabley will be fine. Let us know how it comes out and post some photos!!!