Even I have trouble with this one

[Greg Hermann]

>Actually, I believe the original ZR1 Corvette had a big-block Chevy
>(454?) under the hood.  For those that aren't familiar, the original ZR1
>Corvette was built back in the heyday of the musclecar, the late
>60's/early 70's (off the top of my head, I don't recall the actual model
>years for the original ZR1.)

That was an "L-88, unless I'm dealing with early Alzheimer's--big block
with aluminium heads. 'Twas another number for a (rare) all aluminium big
block, but it definitely was not ZR-1. It mightta been a "Z-11", but????

As with most of those cool sounding names (Z28, LE1, LT5, LS6, ZR1, LS1),
they are Chevy's ordering code for the
>specific equipment.
>
>The more modern ZR1 used a Lotus-designed engine that was cast &
>assembled by Mercury Marine (hmm, fiberglass body and an engine built by
>a boat company;  was the ZR1 actually a "boat"?)

Correct, except that it is the only one. And it does have two injectors for
each cylinder--one primary, one secondary. Also has four cams, 32 valves,
and sixteen separate intake ports. It has primary throttles feeding the
first eight intake ports, with the primary injectors in those eight ports.
I believe that the secondary throttles are "drive by wire", since they are
what is shut down when the key is put into the "valet" position. The
secondary throttles feed the second set of intake ports, which also hold
the secondary injectors.

The LT5 engine had dual cams per cylinder bank, 4 valves per cylinder, for
a total of 32
>valves.  To feed those 16 intake valves, it did indeed have 16 tuned
>individual intake runners.  However, only 8 of the runners were
>functional at lower engine speeds (again, I don't recall the actual
>transition point, but I think it was between 2500 - 3500 RPM.)  This was
>done to enhance low-end drivability without affecting top-end power.
>>From what I have heard/read, the system did work pretty well, but it was
>a VERY expensive way to get more power.

 It has a primary throttle feeding the first eight intake ports, with the
primary injectors in those eight ports. I believe that the secondary
throttle is "drive by wire", since that is what is shut down when the key
is put into the "valet" position. The secondary throttle feeds the second
set of intake ports, which also hold the secondary injectors. This makes me
think that the adda brain might have been doing more than just running
eight more injectors.

One of the more interesting trivia that came out of this is that the
current LS-1 motor was the direct result of a bunch of secretive work by a
bunch of Chevy engineers who were basically saying "Oh yeah--watch this
shit!!" to the elements of GM's top brass whose decision to farm the design
of the LT5 engine out to Lotus came across as an insult to them!! The
tendency of the LT5 to have the nose of it's crank break off at inopportune
times only added an exclamation point to another  FUBAR situation (so
typical of GM's top management over the past few decades)!!

Another interesting aspect of the ZR1's ecu is as follows: I have heard
tell that it keeps track of the number of times that the car exceeds 100
and 150 mph, and for how long each time, somewhere in its innards.
Apparently GM has, upon occasion, recovered this info from Vette ecu's in
order to encourage plaintiffs in nasty lawsuits to settle quietly and
cheaply. If the ZR1 ecu is indeed a close relative to other units, it would
be VERY interesting indeed to determine whether this kind of potentially
extremely embarrassing ecu memory ability extends across the board!

----Hey, Code Dudes--a bit of code with which to rewrite this stuff, if it
exists, might be VERY marketable , indeed!!! Might even make someone the
kind of money Cincinnati Microwave has made over the years!! THEY ARE
WATCHING, YOU KNOW!! Someday Al may want to make reading this part of your
ecu's memory a part of your annual emissions check-up--you know--just to
see whether you are one of those bad guys who is helping to melt all the
glaciers!!!
>
>PS - The more I think about, the original ZR1 may actually have been a
>small-block Chevy (350).  I think the big-block version was actually
>called a ZR2.

Maybe I'm remembering engine codes rather than car codes???
>
>
Regards, Greg