Datsun
1500-1600 Used Cylinder Head Info
CYLINDER
HEADS unless specified otherwise are "just off the
engine" and have had nothing done to them. Unless
specified otherwise, heads are bare castings, with seats
and guides only in whatever condition they are in, and do
not include valves, springs, thermostat housing, rocker
towers or rockers. The heads may be offered at different
prices depending on what parts are included. Used heads
would need to be ordered by a mailed in order accompanied
by a money order. Please inquire for delivery costs. A US
Postal Money order is by far the quickest if you have any
kind of time constraint.
HEAD
THICKNESS You can cut off about .050" from an uncut
head before you need to have the "pocket" in the head,
the concave area where the dome of the piston visits;
recontoured. If you mill a head past this point,
depending on how it is cut the dome of the piston will
contact the head. You can also rebuild your engine using
flat top pistons to alleviate this situation forever.
Having the chamber recontoured is no big deal, but many
machine shops routinely ignore this situation.
Another
problem with aluminum heads is electrolysis, which simply
put is the aluminum dissolving into the water. This
situation seems to be aggravated greatly by using
straight water instead of 50/50 antifreeze/water. I've
been told that water with a high mineral content also
increases the likelihood of this being a problem. Any of
you with a chemical or engineering background feel free
to jump in! I've seen some heads that have been
completely eaten through from this process.
When
a head has overheated and warped, most machine shops just
mill the head gasket surface flat and leave it at that.
Many will not check the thickness of the head against
what it was originally (3.248"-3.250"). You may end up
with the problem described in the first paragraph above.
I've also seen lots of heads where the top was never
corrected, to allow the valve cover gasket to seal
properly. When a head warps the whole head warps. You can
tell if you have this problem by laying a straight edge
on the top of the head and seeing if it "rocks" when
pushed down alternately on the each end of the
straightedge. If this is not corrected you may have a
leaky valve cover if head is warped a lot. As a result
people are tempted to keep tightening on the valve cover
nuts. Aluminum doesn't flex much..."SNAP". Once weakened
by cracking, a valve cover will never seal again unless
it is braced and then heliarced. Those valve cover nuts
should be finger wingnuts as if everything else is OK
they shouldn't need much more torque on them then fingers
could apply. Instead you've got those nice big nuts.
"Hey, Ronny the valve cover's leaking, hand me the 3/4
drive impact wrench! The solution is to at least lightly
surface the top of the head to take off the offending
"peak".
WHAT
FITS WHAT? Any 1600 head fits any 1600 engine. There
are a few variations though. There is a SAE thread iron
head and a SAE aluminum head. Neither has air injection
ports for the emission system you may or may not still
have on your car. (All 68-70 USA cars came with the
system). There is a metric aluminum head without the
injection ports and a metric aluminum head with the
injection ports.
To
use an SAE head on a "metric" engine or vice versa you
just need to remember whichever head you have needs the
appropriate threads on all the studs and nuts you use.
The head gasket, manifold and valve cover gaskets are the
same. The heads are set up for either a 2-hole or 3-hole
thermostat housing. Each has a plate for the sealing cap
that is either 3-hole or in the case of the 2-hole
housing actually 4-holes. Some engines came with a extra
plate that goes under the housing that has a mount for
the alternator and/or an engine lifting hook. You can't
switch thermostat housings to a head that isn't drilled
for that type.
The
older heads use a different valve seal. Check the valve
seal info link on the NEW 1600 HEAD PARTS
page
