I currently have two 1976 260z 2+2 s, the idea
being to swap everything that is better on one
of them, to the other, then sell off the inferior.
I’ve already matched the value of what was paid
for the "swapper" with what has been exchanged.
The keeper has complient plates which say:
"260z 2+2 AUto, GRS30-011461, 7/76" and the
stamp on the head says it is an "E80" (no, that is not
a misprint on my account – it really says E80 … and
I’ve never heard of one of those !).
The "swapper" has complient plates which say:
"260z GRS SPORT AUTO GRS30-010127, 1/76"
and the stamp on the head says it is the more familiar
"E88", which we all know is a good head re: compression
and all that.
Any idea on why the complient plates are so vastly
different in description despite being only 6 months
and about 1200 "units" between manufacture ?
The "keeper" has factory air-con (and a huge "slide
into the roof-space" sun roof, which is why I want to
keep that chassis), whereas the "swapper" used to
have an ugly bolt on under the dash aftermarket job.
The differences in head numbers has really got me
beat though – I have carefully checked the stamp to
see if the "0" from the "E80" was in fact a mis-stamp,
but there is no indication it was ever anything other
than a zero and besides, the 8 narrows at the top.
Actually, the 8 seems to have either a slight gap or
a low spot that makes it look like a 9 (with a very
curly tail).
Other differences are:
(1) The radiator in the "swapper" is a three core like
the "keeper", but the cores are closer together and
it is a tad lighter.
(2) (And this is the one I want advice on as to whether
to swap or not), the dizzy on the "swapper" is smaller
than the "keeper", and the vacuum advance unit is
flatter, has an external spring within the dizzy, and is
easier to "pull" with a bit of suck.
The dizzy on the "keeper" has a much deeper vacuum
unit (ugly looking thing) and rather than a visible spring,
has just a long arm sticking out of it into the dizzy. It
is quite hard to get movement out of it by suck (
disconnected, the plate moves easily, so it isn’t jammed)
which makes me wonder if my carbies (su’s now – was
the dafs I think before … a good swap THAT one !)
can actually manage to pull a vacuum advance.
Actually, the larger dizzy looks a bit like the Haynes
manual diagram of the case used for the later model
EI types, whereas the smaller one is the default diagram
for manual points etc in the Haynes manual.
The "swapper", while it was running, although had poorer
compression than the "keeper", was much more responsive
and quicker off the mark etc. Although the SUs have
improved performance (and reduced an overheating
problem) with the "keeper", she is still somewhat reluctant
when the foot is put down. If you put the foot down at
say 110kph, rather than surge forward, a strange
hummy whistle will sound (air-intake to the carbies
perhaps ?) as she oozes upto the new speed.
Now I put this down to timing more than anything else,
but I wonder if this mother of all vacuum units is letting
me down too.
ALthough both cars are autos, neither have the dual
point/extra relay/water sensor thing (any more <grin>) –
nor the EGR stuff – the only thing interrupting the vacuum
line from dizzy to carbie on both cars is from the carbon
canister. Swapping the canisters makes no difference.
Now idle timing on the "keeper" seems to be fine – she
can sit there nicely at about 600rpm if need be (btw, headers
are installed), and revs instantly under no load – it’s just
lacking when accelerating under load – a problem that the
lesser compression car doesn’t have a problem with – it will
spin away up the road, where as the other barely spins on
gravel. (I must admit, the spinner has but standard rims/tyres
on <grin>) – both will cruise the same, but the spinner gets
there much easier and faster.
Now I can’t spring for EI at the moment, but do you think
it worthwhile to swap dizzies (larger one with mega-vacuum
unit, for smaller more responsive unit), or just muck around
with the timing/retard/advance with the one I’ve got ?
DO you think the "E80" marked head is probably a
mis-stamped E88 ?
BTW, my little Tach/Dwell meter thingo that I scored off a
mate the other day but barely know how to use, reports a
"dwell" of "45" degrees, whereas Haynes reports that dwell
should be between 31 to 40 or something like that.
Haynes will tell you on how to adjust the timing, but it ain’t
all that helpful on the "dwell" side of things (pardon my
ignorance – I picked up a timing light for the first time in
my life yesterday <grin> – gotta start somewhere, eh ?)
I’ve actually talked about the "keeper" before in this forum –
many moons ago. Back then it was in regards to an overheating
problem (and fluid loss). For a while I feared it was the head
gasket regarding the fluid loss, but upon exchanging both the
radiator and fan, both problems seemed to be finally rectified
– the old fan was slipping, and the old radiator has had too
much gunk put through it I guess.
The auto box still slips now and then though. <sigh> I am
trying to build up enough nerve to tackle dropping and
swapping the boxes. Mounts need doing on the diff too,
and according to Haynes, you gotta pull the diff to do that
(are they correct about that ?)
All help/advice/ridicule will be accepted with not only
great appreciation, but also with the best of humour
as applicable.
regarDS
2 stock 4 chan. 80w amp. 
, …. it would