||This is just a sample of a typical side
housing as it comes out of an engine.
||The greatest wear is usually opposite the
intake port - in the area of where the lines in the image are
||This is a close up of the above shot. The
depth of the vertical wear groove (from the corner seal) is what determines how
much material needs to be lapped off. Very deep grooves make the housing not
|A fair amount of material can be removed from
the housings - the problem is that it is cumulative. Both in the total per
housing (how many times have they previously been cut ?), and the total of cuts
done on all FOUR surfaces. You can actually end up with an engine that is so
"short" the manifold holes need to be ovaled. The actual limit (which is
virtually impossible to measure) is the radius of the end of the stationary
gear hitting the radius of the eccentric shaft rotor bearing
||This image, (and the one below), are the main
reason for making this page. These images illustrate the dreaded "unknown water
leak" in '86 and later engines. The casting is weak in the water seal groove
area, and the edge of the seal support breaks away.
||This crack lets the water seal slide out of
place, and is VERY hard to diagnose. We fought this car for 6 months - was just
gradually using water. We had to leave the water system heavily pressurized for
over 48 hours before we finally got a little water into the combustion area.
This crack is what we found.
|The fault can be
anywhere around the seal, but is usually in the lower half. We have found a
number of housings with the piece gone already. We check all the side housings
we use VERY carefully before using them. Worst case is to miss one that is just
cracked, but has not moved out of place yet !!
||This is an image of a "burned" housing. These
ones have "blued" areas on the face from overheating, usually due to lack of
oil. They are NOT usable! The metal is hardened, because it is actually
shrunken down in that area.
||An example of what they look like after
lapping (and a LOT of cleaning!).
||Just a shot of our big, ugly, dirty, noisy
lapping machine. The 48" table does four surfaces at a time. We have it stuck
in its own corner, to confine the mess. Normal procedure is to dedicate one
person for one full day to do all we need for the next time period. We prefer
keeping that lucky person confined to the area for the day, and just throw food
and drink in as needed.