Even I have trouble with this one/original ZR1

Ray Quayle ray.quayle at btinternet.com
Thu Oct 8 00:51:35 GMT 1998


Bob,

You got it right in the end.  ZR1 first available in 1970 was a package
that included the LT1 small block, 25 were made.  The option carried on
through 1972 with 8 built in '71 and 20 in '72.  The ZR2 was first
listed in 1970, but none were delivered to retail customers.  The ZR2
was only really offered in 1971, and as you said had the big block LS6,
12 were made.

Michael,

So as you see the original ZR1 wasn't the LT5.  And as for the ZL1,
you're pretty right on except that it was a 427 and not a 454.  It was
basically an aluminum block L88.  The 454 wasn't available until 1970 in
the LS5.

Ray Quayle in England
1986 PaceCar

> From: "Bob McElroy" <rmcelroy at cfu-cybernet.net>
> Date: Wed, 7 Oct 1998 13:59:16 -0500
> Subject: RE: Even I have trouble with this one
> 
> 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.)  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"?)  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.
> 
> Bob McElroy
> 
> 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.
> 
> - -----Original Message-----
> Aren't all the ZR-1 corvettes the overhead cam jobs?.  Aren't
> all these the 16 injector dual runner intakes?.
> 
> ------------------------------
> 
> From: Michael Kasimirsky <mtk at tmc.astm.cmri.cmu.edu>
> Date: Wed, 7 Oct 1998 15:16:38 -0400
> Subject: RE: Even I have trouble with this one
> 
> > 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
> 
> No, I believe the ZR1 was only the late-model DOHC motor version.
> 
> The one you're thinking of was the ZL1, which was EXTREMELY
> rare and came with a 380hp all-aluminum 454 big block in 1969.
> But the 1969 LS6 454 made 460hp, you say?  Well, the ZL1 made
> 380hp at 3800rpm or so (as it was rated), but it also made 580hp
> at 5800rpm or something like that, but to discourage people from
> ordering it (as if it's $5000 price tag wasn't enough) the package
> was intentionally rated below it's power peak.  The ZL1 engine also
> weighed less than the 327 base engine. I believe only 2 or 3 were built.
> 
> In case you can't guess, the ZL1 is the only vintage Corvette that
> I have any real interest in.  :-)
> 
> Michael Kasimirsky            1990 Yamaha FZR400 Superbike Racer
> Loki Motorsports              1993 Kawasaki ZX1100D1 Streetbike Rider
> FASTTRAX & WERA Novice #22  Sponsored by Loki Motorsports, Bridgestone,
> mtk at tmc.astm.cmri.cmu.edu        Street & Competition, and AGV.



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