The advantage to torque to yield bolts is that once they have been correctly tightened and yielded, they will more closely follow the expansion and contraction cycles that an engine will see. It is a given that aluminum and cast steel have different coefficients of expansion. For that reason, aluminum heads on a cast steel or cast iron engine block have always been a problem.
Going back in time, in the 1970s, I was working in a Buick dealership. We had several models that had aluminum heads. The 1964 Special had a 300cid V-8 with aluminum heads. That engine needed the head gaskets replaced about every 30k miles. They used some fancy flange bolts with special washers for head bolts. Still ate up head gaskets.
Later, in the 1980 era, I was working in a Ford dealership when we first saw the stretch bolts in Escort engines. Then around the introduction of the 1.9 engine, head gasket problems reappeared. The factory reps selected several cars with gasket failures, and sent out brand new complete engines to replace them with. They took the failed engines back to Dearborn, and analyzed the failures. That was a big step in head gasket technology.
The gist of the whole thing is that modern engine have much better head gasket life with the torque to yield bolts. The factory engineers tell us not to re-use the bolts. They are much smarter and better educated than I am, so I follow their advice. If you want to take your chances with used stretch bolts, that is your choice. However, I do disagree with recommending it to other less experienced and less knowledgeable folks. That way, when a failure occurs, it will not be because I told somebody to take a shortcut or to "cheap out" on doing it properly.
I do enjoy working on cars up to a point, but I do not want to keep doing the same job on the same car over again for a couple of reasons - time consuming would be one reason and cost would be a second.
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Today's Featured Article - Talk of the Town: The Saga of Grandpa's Tractor - by The following saga is from the Tractor Talk Discussion Forum. Someone. The saga starts with the following message: Hey guys I have a decision to make. I know what you all will probably suggest and it will probably agree with me way down inside, but here it is. I have a picture blown up and framed in my "tractor room" of a Farmall M. It was my Grandpa's tractor, of which whom I never got to meet. He froze to death getting this tractor out of the barn to pull a truck out of the ditch before I was born. Anyway my dad and aunt had to sell it at the auction,
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