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From left to right:
Lifting eye stud- comes new with 5 coarse threads at the bottom. (2 lifting eye studs, with 5 threads each, designed to bare the full weight of an atomic 4 engine as it's being lifted in or out of the engine compartment.) Also, the lifting eye stud is the same length as the regular stud but with only 5 threads at the bottom (versus 8 on regular stud) the stud does stick up out of the head a little more.
Regular engine stud- comes new with 8 coarse threads at the bottom
Remaining 7 studs are modified for use on manifold side of the block- 4 coarse threads at the bottom
Why, you ask, would anybody modify those 7 studs??
Below is why.
On the left is 1 of 7 head studs that came out of the manifold side of the block. The other 6 look similar. There are about 4 good threads left on that stud. The other 4 threads have corroded away because they sit in the engine cooling water, doing no work, except provide a potential obstruction to flow and a potential gathering point for debris in the cooling water. Which, in my case, became a complete blockage to the cooling passage at the #2 exhaust valve, causing a hot spot that resulted in a burnt valve.
On the right is a new engine stud.
Below is the block and head.
Cooling through the block to the head comes through the 6 oblong passages on the manifold side and 5 other holes. In the picture I circled the 5 other holes that provide cooling to the head. The other holes seen on the block are stud holes or clean out holes. I put an "X" on the clean out holes.
Each oblong hole is about twice the size of the other 5 holes. So, using simple math (no fluid dynamics) the oblong water passages provide 70% of the cooling to the head. Which, to me, is further justification for cutting down those studs.
Ok, on this head install I have used the 7 cut down studs on the manifold side, 1 repair stud on thermostat housing, 1 thermostat housing stud, 2 lifting eye studs and the other 6 are regular head studs.
But, here is my future plan for next head removal. 1 repair stud on thermostat housing, 1 thermostat housing stud and 15 lifting eye studs!,
The lifting eye stud has only 5 threads on the bottom, it wouldn't have to be cut down to go on the manifold side of the block (1 thread in the cooling passage wouldn't be much of an obstruction) and the best part, it sticks up through the head far enough for "double nut technique" stud removal.
Lifting eye stud- comes new with 5 coarse threads at the bottom. (2 lifting eye studs, with 5 threads each, designed to bare the full weight of an atomic 4 engine as it's being lifted in or out of the engine compartment.) Also, the lifting eye stud is the same length as the regular stud but with only 5 threads at the bottom (versus 8 on regular stud) the stud does stick up out of the head a little more.
Regular engine stud- comes new with 8 coarse threads at the bottom
Remaining 7 studs are modified for use on manifold side of the block- 4 coarse threads at the bottom
Why, you ask, would anybody modify those 7 studs??
Below is why.
On the left is 1 of 7 head studs that came out of the manifold side of the block. The other 6 look similar. There are about 4 good threads left on that stud. The other 4 threads have corroded away because they sit in the engine cooling water, doing no work, except provide a potential obstruction to flow and a potential gathering point for debris in the cooling water. Which, in my case, became a complete blockage to the cooling passage at the #2 exhaust valve, causing a hot spot that resulted in a burnt valve.
On the right is a new engine stud.
Below is the block and head.
Cooling through the block to the head comes through the 6 oblong passages on the manifold side and 5 other holes. In the picture I circled the 5 other holes that provide cooling to the head. The other holes seen on the block are stud holes or clean out holes. I put an "X" on the clean out holes.
Each oblong hole is about twice the size of the other 5 holes. So, using simple math (no fluid dynamics) the oblong water passages provide 70% of the cooling to the head. Which, to me, is further justification for cutting down those studs.
Ok, on this head install I have used the 7 cut down studs on the manifold side, 1 repair stud on thermostat housing, 1 thermostat housing stud, 2 lifting eye studs and the other 6 are regular head studs.
But, here is my future plan for next head removal. 1 repair stud on thermostat housing, 1 thermostat housing stud and 15 lifting eye studs!,
The lifting eye stud has only 5 threads on the bottom, it wouldn't have to be cut down to go on the manifold side of the block (1 thread in the cooling passage wouldn't be much of an obstruction) and the best part, it sticks up through the head far enough for "double nut technique" stud removal.
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