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Discussion Starter · #1 ·
OK so at the risk of sounding incredibly stupid, what would happen if I reused the "torque-to-yield" bolts that "can't be reused" when I put my head back together? Why can't these bolts be torqued to spec like any other bolt? I don't doubt that they are unusable, I just want to know WHY. OK maybe I doubt a little bit.

And, what sense does it make to have a "cylinder head kit" with all the gaskets but not include these bolts. Obviously I need the bolts too, if they "can't be reused." But that question is for Autozone, not TCCA.

The thing is, the car is beaten, battered, and looks like it has been driven thru more than one brick wall. It's not worth putting much money into, and I only need it for another 10,000 or so miles.
 

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They break off in the block (or at least the first one did). I did it once on a Escort 1.9L and will never put myself through that heartache again :)
 

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OK I answered my own question. This site was helpful and succinct: Learn About Torque to Yield Bolts

As it turns out, the bolts actually stretch and change shape when they are torqued to spec. So this makes sense, I suppose. I'll pay for the dang things.
you can get away with reusing them, but whats 30 dollars over a 400 dollar tap/die set with helix coils to drill out a broken off bolt......

its risky but then again most of these cars aren't even worth the 30 dollar investment X_X
 

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You really can't get away with reusing them. Often when they are reused, they do not hold the head down as tightly as they should, and blown head gaskets are a strong possibility. New head bolts are the only way to go. So its not just about one breaking. Blowing a head gasket is never a minor thing, there is a good chance that coolant can get into the oil, and when that happens, it endangers the entire engine.
 

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I wonder if it is stupid luck then, I've been in the parts business for 10 years. I knew about TTY bolts from day one, every application that has them and I have a customer purchase a head gasket for, I remind them and explain to them about TTY bolts. They never buy bolts.

I don't rely on luck, which is why I have a box of head bolts for the Vulcan in the B3000.
 

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I wonder if it is stupid luck then, I've been in the parts business for 10 years. I knew about TTY bolts from day one, every application that has them and I have a customer purchase a head gasket for, I remind them and explain to them about TTY bolts. They never buy bolts.

I don't rely on luck, which is why I have a box of head bolts for the Vulcan in the B3000.
You really expect your customer to come back and say "You were right"?
 

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I paid the dumb tax on reusing TTY bolts many years ago and won't do it again. Thankfully, the broken off piece in the block spun right out when I started drilling into it with a reverse drill bit.
 

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Discussion Starter · #10 ·
I'll play it safe

I'm picking up the gaskets tomorrow and new head bolts.

Reusing the valve cover and exhaust manifold gaskets is as risky as I am going to get on this one. New head gaskets and intake gaskets, new head bolts.

So tomorrow night we'll see how this replacement head goes. Picked it up today, the valves look real pretty compared to the head that came off on Saturday. Couldn't bear the $250 to have it rebuilt, so I picked up a low-miles head from a yard for $60. That I can manage.

Thanks for all your input!
 

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I went fel-pro and NEVER looked back. :)

Good that you decided to not reuse the headbolts. :)

TTY bolts hold once. and that's it.
 
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