Linhai 257: 1) Head Repl Leaks AF Joint w Block 2) Won'tFire  By  bob123456789 (Read 2,866 times)

Just measure the depth of the dowel pin holes,,,both of them,,,add them together then measure the dowel pin length,,,the dowel pin total should be less by at least a few thousands,,,,keep in mind when you measure the holes that you keep in mind the dowels are hollow and measurements should be at the sides of the holes

Those pins are short enough to work with a plain steel head gasket so with the laminated one you should have plenty of movemement to squish it unless the studs themselves are too short. I could not see clearly enough from the picks if both sides of the head gasket are matching the machining of the head and cylinder. When you put the dowels in the head and lay the head gasket in place on it is the alignment good or are there areas where it just barely covers the cooling ports?

Usually you start bolting the head back on at the top right bolt, bottom left, bottom right and then top left. First time you make them hand tight, next 5 lbs doing all four in the same pattern, 10 lbs doing all four again in the same pattern and then you can consider another increment between that and final torque or just go for it again following the same pattern. After the four main head bolts are torqued then you can tighten the timing chain side cover fasteners. If you do not follow a tightening sequence in an orderly and incremental fashion you can warp or crack the head and end up with frustrating leaks.

the first thing you need to do is to eliminate possible causes of the leak.
if at all possible, get rid of those acorn nuts.
second, ensure your dowels have clearance, this doesn't mean "it appears they clear".
this measurement must be made with a depth gauge (T-square type) of micrometer.
place dowels in block making sure they seat, measure dowel pin height, record reading, measure dowel pin cavity, record reading.
dowel pin height MUST be less than cavity depth.
do not take this measurement by "eyeballing it", or by a ruler or yardstick, or pencil, twig, or anything other than a micrometer.
the above procedure must be followed, or all you will be doing is chasing your tail.

You may end up with oil leaks if you use lock washers on that head since the valve cover appears to be an integral part of the head with the studs going right through it which is why they use the Acorn nuts to hold it on. Aluminum flat machined washers would be the most you would use with that type of setup if the studs sticking up through the head appear to be too long. You can measure with your calipers to see if the acorn nuts are deep enough to accept the length of the studs sticking up through the top of the head. Oil is many times pumped up via one of the stud bolt channels so if you do not use the acorn nuts you could have issues with oil leaks.

The book calls for oil to be applied to the head bolts so if you put them on dry then yes that would result in the clamping force being too light even though the torque was correct.

Using the end of your caliper is the correct method for measuring depth as long as you were certain to hit the button to calibrate it and zero it out before you began.

Have you ever used or looked at a set of calipers? The back end of them is a depth gauge. More versatile than a single purpose Micrometer which would require a set of three to cover the duties of one decent caliper and faster to use. Stop by your local Harbor Freight or other tool store and hold a set in your hands. You might be tempted to pick one up for you workshop.

DOH.
and to think i used them almost every day.

it's quite possible that the calipers we used wasn't design to measure depth, because we were never told they could be used as such.
but yeah, that particular caliper looks like it could be used.

i think this particular caliper was specifically designed so that it could measure depth, and in purchasing one you should make sure the extension is narrow enough.
i don't think ours was that narrow.

the depth gauges we used only had a pin 1/8 inch wide.

i would suggest that if a caliper is purchased with the intent of being used as a depth gauge, that the extension is narrow enough.