Torque to yeild bolts

PEI Rob

There is a simple question to your answer. A TTY bolt will have slightly more tension (big variations too) when re-tighten using the same lubricants and same exact tightening sequence. However, each bolt would vary greatly on the load once the material had already been plastically deformed (yielded).

Here is why: A TTY bolt is designed to be stretched just past the yield point of the material for a consistant load (using the the .2% offset stress/strain chart for the alloy used). Just as the material is yielded the force drops for just a moment then rises again. It is "more forgiving" to arrive at the correct load using this method.....sort of a like having a "broad tune" on a PPC. In other words the engineers designed the bolt with the final 90 + 90 degree turn to go into the more forgiving range and arive at a uniform load for all bolts

Once the bolt is re-tightened using the same method the bolt will posses maybe 10-15ksi more strength...thus the higher clamping load.
 
My son has a ATI procharger on his mustang with a intercooler and runs 7 psi, my turbo on the truck will make as much as 30 lbs of boost. I don't know of any Mfrs that recommend's reusing the TTY bolts. Nesikachad, if you ever have to remove the heads on your goat, I would consider ARP studs.
 
Chad

My custom 67 Chevelle has a iron block,( .060 over 454 with a 1/8 Lunati stroker), with Edlebrock oval port Big Block Heads. She has a fairly mild street roller, with just 9-1 compression. (burns unleaded premium). I assembled it with an entire ARP bolt kit.

I have been thinking about adding a blower, there are so many out there now, centrifugals, standard roots, and screw type. The blower set-up would also be in conjunction with a electronic fuel injection.

What's the best unit for a good strong street set-up?? I am looking at no more than 10-12 pounds of boost, as the engine puts out an honest 500 with the 800 edelbrock carb. I doubt the 12 bolt posi rear end, (3.32 gears)l will take much more, I sometimes cringe when I shift at 6200 now. I would love to convert the entire rear assy to a custom 9-inch Ford.

I have a beefed up 700 R tranny in this thing, I have always hated that 3.07 first gear, unloads way too much torque with too much gap between 1st and 2d. That new 6 speed Automatic that B&M has out looks real good. It;s supposed to be as strong as a Turbo 400.

If I did everything I wanted to to my Chevelle, I would spend about $40,000. ..........jackie
 
Whipples are pretty dern cool. Very efficient and they don't surge as much as a typical/traditional roots style. New FI systems can probably tune that out though.

Jackie, another option is sell that engine, find a running late model LS1 or LS2 and then put the screws to it.

check out LS1GTO.COM or LS1.com if your interested. They aren't the cheapest engines to build when you get carried away(mine was well into 20K by the time I was done) but they are impressive little buggers. I have gotten over 30mpg with this set up. lean idle fuel trims are a beautiful thing! Be quite a bit lighter than that big ol RAT as the cases/heads are alloy. 10:1 CR out of the box too and the blowers love em!

A stocker LS1 with a Maggie will put out around 400hp to the wheels and it'll run ice cold, start, drive, idle like a stocker.

Good luck on your build. I'll quit derailing this thread now.

Cheers,

C
 
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Short annealed bolts with course thread are more likely no.
Long hardened bolts with fine thread are more likely yes.

All head bolts are too short for one thread length not to reach the elastic limit.
 
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