Bell-housing alignment help
OK. So I clipped the mag mount to the block and dialed the face and the edge of the crank. Fine.
Then, I clipped the mag mount to the crank, and I dialed the face of the block, where the bell mounts.
At 3:00 on the block, I zero it.
By 2:00, I'm at -18 thou.
At 12:00, I'm at -24 thou
At 11:30 I'm at -27 thou.
At 10:00 I'm at -14 thou.
At 9:00 I'm back to -5 thou.
I did the same thing with the block plate mounted, thinking surface irregularity or anything like that. (I do have a little-- about 4 thou of bounce as it goes over ridges in the paint) With the block plate mounted and dialing the plated but unpainted surface of the plate, I get identical results.
I turned the crank by 90 degrees and re-dialed it, thinking anything with the flange being bent or anything. Exact same results. That tells me the problem isn't in the crank.
The entire flange that the bell mounts to is not in the same plane as the face of the crank!
If the block is machined 24 thou shy at the top of the block, then that cocks the entire bell forward... and the lever arm to the ring where the tranny mounts is more or less the same as the lever arm from the crank out to the flange -- So, no surprise, the ring is cocked upwards and forward by about the same -- about 25 thou. Giving me 52 thou of total runout.
My freaking block is machined out of square.
Even if I abused the crap out of the bell to get it dialed in "right", it would still be tipped forward, and there would still be an angular misalign between the line of the crank output and the line of the tranny input, which I can't imagine does anything good.
I think it's time to get a new block. :(
OK. So I clipped the mag mount to the block and dialed the face and the edge of the crank. Fine.
Then, I clipped the mag mount to the crank, and I dialed the face of the block, where the bell mounts.
At 3:00 on the block, I zero it.
By 2:00, I'm at -18 thou.
At 12:00, I'm at -24 thou
At 11:30 I'm at -27 thou.
At 10:00 I'm at -14 thou.
At 9:00 I'm back to -5 thou.
I did the same thing with the block plate mounted, thinking surface irregularity or anything like that. (I do have a little-- about 4 thou of bounce as it goes over ridges in the paint) With the block plate mounted and dialing the plated but unpainted surface of the plate, I get identical results.
I turned the crank by 90 degrees and re-dialed it, thinking anything with the flange being bent or anything. Exact same results. That tells me the problem isn't in the crank.
The entire flange that the bell mounts to is not in the same plane as the face of the crank!
If the block is machined 24 thou shy at the top of the block, then that cocks the entire bell forward... and the lever arm to the ring where the tranny mounts is more or less the same as the lever arm from the crank out to the flange -- So, no surprise, the ring is cocked upwards and forward by about the same -- about 25 thou. Giving me 52 thou of total runout.
My freaking block is machined out of square.
Even if I abused the crap out of the bell to get it dialed in "right", it would still be tipped forward, and there would still be an angular misalign between the line of the crank output and the line of the tranny input, which I can't imagine does anything good.
I think it's time to get a new block. :(