On Oct 19, 6:33 pm, "mmc" wrote:
wrote in message

...

Years ago when I installed this diesel in my sailboat, I read about
aligning the engine output shaft with the prop shaft by using a valve
clearance guage to check all round the round pieces that bolt the two
together. One would tighten or loosen the engine mounts to make it
the same all round. I can no longer find these directions and am
having problems getting it just right. One side is off by .008" and
all I can think of is slightly rotating the engine (about a vertical
axis) by pushing against the engine mounts but this doesnt sound
right. Thoughts?

DB,
You're doing it right. I couldn't remember the tolerance so did a google on
aligning sailboat engine and found this on a site (http://www.alberg30.org/maintenance/...n/Diesel/Insta...)
about swapping an Atomic 4 for a diesel:

The most critical part of an engine replacement is the new engine alignment
with the prop shaft. The tolerance on this is .004" maximum. This
measurement is taken between the engine flange and the shaft flange. It is
in two planes, vertical and horizontal.

If you can't get that close you probably need shims.

mmc, thanks. I was considering living with my .008" diff but I'll
give it another try.
However, I think the height and horizontal adjustment are dead on.
Unfortunatly, the plane of the engine output flange is misaligned by
roughly .3 degrees (three tenths of a degree). I got this number by
taking the size of the gap between the two flanges (.008) divided by
the radius of the flange and taking the arc tan. I really think I
should use the diameter of the flange which would give me .15 degree.
Is this close enough?
The bolts slide in very easily indicating good alignment.