j-d wrote:
As you run that 460, that big heavy head expands and contracts, but not as fast as the relatively light manifold. As the manifold heats and cools, it gets thicker then thinner and longer then shorter. That longer and shorter, puts sideways stress (engineers call it Shear) on the bolts. So the head ends are being "worried" fore and aft, bending the bolts. The holes in the manifolds are oversized, partly to allow for some thermal shifting. But the threads as solidly into the head. That focuses the strain from all this worrying, right in the thread nearest the head surface of the port.
Great Catch, Ron! On asking when they broke.
Now if they're worried AND stuck, they'll probably still break under the torque of removal effort.
Now if they're worried AND stuck, they'll probably still break under the torque of removal effort.
Not sure what you mean here? Do you think I'm more likely to have problems removing the bolts?? I really don't want to break an easy out in this bolt...
I know this - removing the existing bolts was not easy - they were all very tight - but at least they all came out without breaking!
