torque to yield bolts?

When I replaced the Neon's head gasket the head bolts were TTY, the FSM laid out how they could be reused if they passed a visual. The visual was to lay the thread on a flat surface and if there was no gap between the thread "points" and the surface you could reuse them.

So I did and that head gasket eventually failed, so I sprung for new head bolts and yet another head gasket, all factory parts at this point, and no failures.

I would probably go with the ones from Rock Auto if it's in stock.

thanks for the replys,ill find new tty they are cheap insurance

Sorry to come in at the end but I think I need a crash course in tty bolts for Magnum intakes. I just bolted on a Procomp dual plane carb intake on my 360 Magnum yesterday. I used new bolts from the dealer because the originals had some rust pitting on a few that were by water jackets. I used the full set from the dealer. So, excuse my ignorance but why are you all making tty bolts seem so inparitive?? Is there something I don't know about the Magnums??

nope, not that I know of, and I've put 3 or 4 of these Magnum engines together. I usually clean up and re-use the stock bolts. if they're too corroded then I just buy new grade-5 bolts from the local hardware store. they only need 12 ft lbs of torque. if a bolt is TTY at only 12 ft lbs....that's some pretty weak/soft metal!

I never even used a torque wrench, I just use my 3/8 drive socket and grab it right over the top of the pivot point, and twist my wrist to tighten the bolts.

I've got a 100% success rate...no vacuum leaks, no coolant leaks, no oil leaks. and that's using the 2bbl M1 intakes and the stock kegger intakes.

so is it so critical? what are the odds of taking a true/false test (50/50) with 4 12-part responses, guessing blindly at each one, and getting a 100% overall score?

Thanks!! I'm a tad sketchy on mine though, the book said torque is 45 ft/lbs and I had a feeling that was high. Made a couple calls to take a census of opinion and decided on 25. I'm sure it will be ok tho.

Be carefull overtorquing vertical-bolt intakes. Can cause head sealing and other issues.

I believe some Felpro magnum intake gasket kits come with bolts.

TTY BOLTS HAVE THE PRIMARY BENEFIT OF DISREGARDING A TORQUE WRENCH WHICH GIVES A FRICTION READING. IN OTHER WORDS, THE BOLTS ARE STRETCHED A PREDETERMINED AMOUNT (DISREGARDING TORQUE WRENCH FRICTION READINGS... COMMON FROM THE THREADINGS) SO THEY ULTIMATELY PROVIDE EQUALIZED CLAMPING FORCE UPON THE GASKET AND CASTINGS (MORE EQUALIZED CASTING DISTORTION, IN PARTICULAR FOR CYLINDER BORES). THE OE SERVICE MANUAL SHOULD INDICATE IF THEY CAN BE RE-USED, AND IF YES, HOW MANY TIMES THEY CAN BE RE-USED. IF YOU ARE IN ANY DOUBT, SIMPLY REPLACE ALL OF THE TTY BOLTS EACH TIME FOR YOUR OWN PEAC OF MIND.

THERE IS A SIMILAR METHOD TO TTY -- AND THAT IS CALLED "TORQUE-TO-ANGLE" AND REQUIRES A SPECIFIC ANGLE GAUGE ATTACHED TO A WRENCH.

ALWAYS REFER TO THE OE SERVICE MANUAL TO DETERMINE IF THE BOLTS (TTY OR TTA) CAN BE RE-USED AT ALL.

I USED TO WORK FOR A MAJOR GASKET MANUFACTURER AND WE TAUGHT THESE NEW CLAMPING TECHNIQUES (CAME INTO THE INDUSTRY ~MID-80S) TO OUR CUSTOMERS.

I've done more than a few intakes without a torque wrench. Was just trying to be official with this particular build. Same kind of reason I hunted for a replacement head instead of using the one with cracks between a couple valves like everyone said would be ok lol.

I have never worked on a Magnum engine. But I have worked on the 2.2, 2.0, and 2.4 motors that have TTY head bolts. They all have some type of initial target torque followed by a "plus 90 degree" tightening instruction. The second operation is where the bolt actually deforms and 'stretches' because the yield point of the bolt metal has been exceeded. Just like pulling on anything until it 'gives', the bolt has become permanently longer and thinner. If you re-use it, the part of the bolt that is going to stretch the second time is smaller than a new bolt and won't give you the design clamping force. I won't re-use them regardless of the check the FSM has. As to substituting conventional bolting, the whole purpose of TTY bolting is to get more uniform clamping force than you can with a simple torqued bolt. If the clamping force of conventional bolting is adequate, there is no reason you can't use them. But keep in mind the factory used them for a reason.