on my 96 LT4-

Some say they are TTY and not reusable.

Some say they can be reused.

I think what muddies the waters is the FSM. It states to torque to 22 Ft Lbs initially and then use the Torque Angle method for the final tightening. That does not necessarily mean that bolts are TTY.

I have also read that you may use the three step torque method to a final 65 Ft Lbs instead.

What say you all?

Eddie

 

They're TTY. Toss 'em and spend the $60 on ARP.

 

Check into Pioneer...They arent ARPs but a nice step up from stock and they are dirt cheap.
Summit or Jegs should have them.

 

What is your source for that statement? Why doesn't the FSM state that.

It's not that I don't believe you, it's just that people emphatically stand on both sides of the question.

 

Are these the right ones. They are cheaper than I thought.

I have searched this question high and low. You will find 1/2 say TTY and the other half say they are reuseable. Annoying.

 

Actually it does state it in the FSM. Unfortunately it's in some obtuse location that is next to impossible to find. I'll have to see if I can locate it again, it's been years. I also recall it being in the book "How to Rebuild LT1/4 Engines".

 

Can't help you on the 96, but my OEM head bolts on the 92 were so stretched I was glad I had bough a set of the ARP head bolts. In some cases I had to hit them with another head bolt to get them out of the head

My ARP's have been great.

 

Did you use the "3 step torque method" or the "torque angle method?"

 

I switched to the ARP bolts and used the 3 step method.

 

This has been addressed and kicked around on all the the 8 or so sites I regularly visit and probably more
.
I've never been able to find anything that emphatically says LT1/L98 head bolts are TTY, nor has anyone else who supports the TTY claim been able to post the source supporting such a claim.

I suspect the LSx series engines were the first to use TTY head bolts, but that's yet another assumption. I'd have to track down and compare photos and part numbers to distinguish the difference. One poster, on another Forum, posted he'd seen both types, side by side, and the difference between them is glaringly apparent.

Neither my Factory Service Manuals (86 and 96) nor my Haynes CHEVROLET, CAMARO, PONTIAC, FIREBIRD 1993 thru 1996 All Models, nor My "Small Block CHEVY PERFORMANCE Volume Two: 1982 and Later" (written by John Baechtel) manuals identify them as TTY.

Some assume that because there is a different torque procedure listed that the stock head bolts are TTY, but that's just an unsupported assumption.

I've spent hours going from cover to cover on my 96 GM FSM and it's not there; no mention that 96 LT1/4 head bolts are TTY. So absent any irrefutable evidence to the contrary, I'm convinced they are NOT TTY.

Whenever I post something that becomes controversial, I like to post my source(s). Like if I posted that LT1/4 head bolts are TTY - I'd be prepared to post my source for that claim.

Like the NASA PhD engineer said in an interview "Claims made without the supporting science is just making stuff up".

Jake

 

I agree 1000 %. I removed the heads this afternoon. I am not sure I would know a TTY bolt if I saw it but they looked like regular bolts to me. I searched for it in the 96 FSM also and didn't find anything.

Like you said, no one has presented any concrete documentation either way.

 

Asking if they are TTY or reuseable 3 step is in some ways the wrong question. The better question is if it is a good idea to reuse head bolts on a high performance engine where you want the most uniform and stable clamping force.

On a pedestrian low rpm engine it is not such a big deal - start spinning it hard and the equation changes.

You don't mean to tell me that after potentially spending several thousand dollars building your 6,800+ rpm LT4 that you would then step back and look at the head bolts and say "nah, no way am I wasting $60 on a new set of head bolts." Its okay with me if that is your decision, it just wouldn't be mine.

As I understand it, the TTY method is a more accurate way to tension the bolts. I'll even go out on a limb and say that in any given shop you will find more variation in torque wrench accuracy than TTY tools.

Thomas

 

I wouldn't skimp $60 on a high dollar engine build to reuse old head bolts. I have seen HP LS engine builders junk the tty bolts in favor of ARP head and main bolts.

 

Yep, those are the ones that I used.

 

I don't know either if the bolts are TTY but I can tell you what I encountered on my '85. I rebuilt the engine and it was so close to stock I figured the old bolts would be fine. As I always do, I cleaned the threads in the block and oiled the bolts when I put them back in. I used the 3 step method and was just finishing the very last bolt on the very last sequence when it snapped at 10 or so ft lbs. short of it's goal. I removed both heads, went and got a set of ARP bolts and put them in. I will NEVER reuse head bolts again.

 

Some of you folks are missing the point. I plan to use new head bolts. The question is whether the OEM bolts are TTY or not. I think that a lot of folks do not have a clue what is different about a TTY bolt.

 

Most TTY bolts Ive seen have a weird shouldr on them almost like they neck down a bit. The PP bolts on my T56 are like that, one time use only. No expert here though perhaps there are some that dont have that shoulder on them?!

 

Here are the bolts in question. They do neck down a bit about and inch below the head.

I think the only definitive way to know if they are TTY is to compare the length to a new one. TTY bolts are designed to stretch beyond the elastic range into the plastic range. That means they don't return to their original lengths when loosened.

 

TTY bolts






ARP head bolt

 

I agree. Reading some of the posts in this thread, I also think some people don't understand the difference.

The stock bolts are not TTY. The "torque precedure" for tightening the bolts, does not a TTY bolt, make.