Crankshaft Alignment to Block

[tennsmith]

Originally Posted by tbirdtbird

try it, it works.
takes some trial and error.
We don't just shove a .010 shim under each ear and call it good. We dial it in. We have different shim thicknesses. Only once have I ended up using the same exact thickness under each ear.

Despite the 4 bolts that you do not shim, there is some flex to the casting, and that is why the shims at the ears work. That is what is wrong with the design of the FW housing to begin with. But we have to work with what we have.

I can "buy into" your and Tom's explanation that the housing does flex and shimming at the top ears can move the outside surfaces...but do you think it is realistic to expect to move those surfaces enough to make all points within 0.005" ? I guess to quell my own curiosity, I'm going to put the housing back on and play with moving the top tabs while indicating the surfaces at 3 and 9 to see if there is any movement. All I've been able to do so far is bring the 12 position into alignment with either the 3 or the 9, but not change or effect the values at 3 and 9.

My temptation is to mount the housing to a large aluminum plate, for rigidity and support, at the bellhouing interface and then toss it up on the milling machine, shim it to remove at least .005" from the high side and resurface the face that mounts to the block. I realize this "mates" this housing to this block forever, or until the main bearings are refurbished, at which time, it may necessary to reface the housing again......