Looking for any details on which parts may have been used, for which reasons, in which model years, etc. The more info the better. If this isn't the appropriate forum, please relocate. Thanks!

 

01s started getting some stuff like the LS6 clutch and LS6 intake.

 

About 25% of 01 and 02s have LS6 blocks. My 00 has an LS6 style block with an LS1 block part number, it's a freak.

 

Al: LS6 blocks... do you mean shortblocks or longblocks?

 

LS6 blocks, not the LS6 heads, though- darn! All 2001-02 got the LS6 intake, with no EGR-

 

So they got the LS6 cylinder case, or the entire LS6 shortblock which includes the different cam profile? Was there a compression difference between those which came with the LS6 block and the 'normal' blocks?

 

Just the block.

The compression on the LS1 vs. LS6 has nothing to do with the block.

The blocks are basically identical anyway

 

I thought perhaps if it was the entire shortblock that the piston design might be different or the top ring closer to the top. So even though these cars received the LS6 block, they didn't receive any components which gave them a performance advantage, correct?

So my next question is, a friend hydralocked his '01 motor a few years ago and he chose to have the dealer use the LS6 motor for a little more money. Since the LS6 motor never came in the F-bodies from the factory, he has a performance advantage over any LS1-based F-body you could have ordered direct from the factory, correct?

What I'm trying to find out is if by choosing the LS6 motor he unknowingly made his car ineligible for these class rules:

[code]
15.10 ENGINE AND DRIVE TRAIN
Vehicles may only exceed the allowances of 13.10 as specified herein.
A. Engines must retain standard type lubricating system, but may
have any oil pan (Accusump-type systems allowed), oil pump
and pickup, oil coolers, oil or fuel filters. Fuel filters must be of
automotive type and may serve no other purpose; a substituted
fuel filter may not be used as a reservoir. Substituted fuel filters
may not exceed one quart total capacity. A permitted oil cooler
may be positioned in an opening in an allowed spoiler, provided
no unauthorized modifications are made in order to perform the
installation.
B. Heat shields may be added.
C. Induction allowances are as follows:
1. Carburetors, fuel injection, and intake manifolds are unrestricted,
subject to 15.10.D. Alternate throttle linkage and
connections to facilitate installation of allowed induction
systems are permitted, but may serve no other purpose. If an
induction system item is allowed to be removed and its original
mounting bracket can be removed by simply unbolting it,
the bracket may be removed as well.
2. Except for standard parts as defined in these rules, the external
use while on course of liquids, ice, dry ice, refrigeration
systems, vaporized compressed gases, etc. to reduce the
temperature of the intake air charge is prohibited. Wrapping
of intakes with liquid-soaked fabric is not permitted.
3. As utilized only on engines originally equipped with forced
induction, induction charge heat exchangers (known as “intercoolers”
or “charge air coolers (CACs)”) are unrestricted in
size and configuration. Air-to-air CACs and radiators for airto-
liquid CACs must be cooled only by the atmosphere, except
for standard parts. Body panels, fascias, or structural mem93
bers may not be cut or altered to facilitate CAC installation.
4. Turbochargers and/or superchargers (“forced induction”)
may not be added, changed, or modified (this does not allow
ceramic coating of turbochargers). On vehicles originally
equipped with forced induction:
a) No hardware changes or alterations to turbocharger(s) or
supercharger(s), in size or number, are permitted. Turbochargers
or superchargers may be updated/backdated
only in conjunction with the accompanying complete
engine unit.
b) No changes are allowed to waste gate(s) size, number, or
location. No changes are allowed to variable-geometryturbine
(VGT) hardware.
c) No changes are allowed to supercharger drive system
pulleys. Belt tensioners may be added/changed to reduce
belt slip.
d) No changes are permitted to blow-off/pop-off valves.
e) Compressor bypass valves (CBVs) are considered part of
the air intake system, and may be added, replaced or
updated/backdated independently of the other components
of a forced induction system.
f) Boost regulation systems, either electronic or mechanical,
and electronic fuel cuts referencing boost pressure may be
altered or modified except as prohibited herein. Boost
pressure changes resulting from authorized changes are
permitted.
D. Traction and/or stability control systems, as defined in 12.11,
must be standard parts at standard settings, or electronically
disabled.
E. Air cleaner(s) may be changed or removed, velocity stacks may
be added.
F. Emission control devices may be modified or removed. This
permits the oil filler cap to be modified or substituted, but does
not allow valve covers or cam covers to be altered to install a
breather or for any other purpose.
G. Intake water injection systems are allowed.
H. Fuel lines and pumps are unrestricted except as specified herein,
as long as they do not pose a safety hazard. Fuel lines may be
no larger than 1/2" i.d. and may only connect to the original fuel
tank or allowed fuel cell. They may be no longer than necessary
for reasonable and safe installation, and may serve no other
purpose. A single fuel feed line may be used. A single fuel
94
return line may be used, and a fitting for connecting it may be
added at or near the top of the fuel tank. This does not authorize
“cool-cans”.
I. Exhaust manifolds and muffler systems are free, except that they
must be quiet and terminate behind the driver. Exhaust heat
shields may be removed. Rear- and mid-engine cars without
exhaust headers/manifold systems may use any exhaust system
that meets the requirements of 3.5. This permits the removal of
“heater boxes” in order to install headers on such cars.
J. Engine mounts may be replaced, but must attach in the factory
location(s) without additional modification or changes. Engine
position may not be changed. Hydraulic shock type rear engine
locators, or bobble struts, may be replaced by manufacturer’s
performance part or aftermarket replacement part. This part
must retain factory dimensions and attachment points, including
factory design. (Example: If factory locator/bobble strut is gas or
hydraulic piston type, replacement part must be gas or hydraulic
piston type.)
If one or more non-OE engine mounts are used, 15.10.K does not
apply and a torque suppression device may not be used.
[/code]

Cont'd in next post...

 

[code]
K. One bolt-on torque suppression device may be used. A torque
suppression device attaches from the engine to the body, frame,
or subframe in one location, and controls engine movement at
that location along a single axis only. It may serve no other
purpose.
Examples of permitted devices:
1) a chain
2) a rod with spherical bearings at each end.
Examples of devices not permitted:
1) any link which confines movement along more than one axis.
2) an engine mounting plate, or one or more plates rigidly
bolted between the engine and the frame.
Holes may be drilled to mount a torque suppression device. The
installation may not include the welding of any plate(s) to the
bodywork or to the motor mount(s), nor may it include multiple
non-parallel links.
If a torque suppression device is used, 15.10.J does not apply
and replacement engine mounts may not be used.
L. Engine cooling radiators may be replaced with alternate parts
subject to the following restrictions:
1. Radiator core dimensions (width, height, thickness) must be
95
no smaller than the standard part.
2. Radiator must mount to OE radiator mounts.
3. Fluid capacity and dry weight of the radiator must be no less
than that of the standard part. Installation of an alternate
radiator may serve no other purpose (e.g. to allow a cold air
intake passage).
M. The engine fan and fan shroud (unless it serves another purpose,
e.g., as an alternator/generator mount) may be removed,
modified or replaced. Electrically driven fans are allowed. Flex
fans are not allowed.
N. Transmission mounts may be replaced, but must attach in the
factory location(s) without additional modification or changes.
Transmission position may not be changed. The amount of
metal in a replacement mount may not be increased relative to
the amount of metal found in a standard mount for the particular
application. Solid metal mounts are specifically prohibited.
O. On two-cycle engines, the ports must be of standard heights, size
and configuration; crankcase volume and reed plates must not
be altered.
P. Any metal clutch assembly, metal flywheel or metal torque
converter that uses the standard attachment to the crankshaft
may be used. Non-metallic friction surfaces (e.g. clutch disks)
are permitted. Dowel pins may be added. Any hydraulic clutch
line may be used. Minor repositioning of the clutch slave cylinder
is allowed to accommodate the alternate clutch, but the unit
may not be relocated and the repositioning may serve no other
purpose. This allowance does not permit the substitution of
slave cylinders or the use of non-original methods of clutch
actuation (e.g. pull type versus push type).
Q. Any mechanical shift linkage may be used.
R. Limited slip differentials are permitted. This permits locked differentials,
either by design, welding, or mechanical means. Differential
cases, internal differential parts, and axle stubs may be
machined as required for clearance and installation to the extent
that material may only be removed, not added, and the exterior
of the case may not be altered in any way. This machining may
serve no other purpose.
S. Cylinders may be rebored to no more than .0472 in. over standard
bore and the appropriate standard oversize piston may be
substituted. This overbore dimension is an absolute limit; no
additional tolerance is permitted to accommodate wear. Cast or
forged, non-stock pistons of the same dimensions and configuration
as original equipment pistons may be used. Additionally
the replacement pistons must be of the same weight or greater as
96
the original equipment pistons. Replacement pistons must
match OE piston configuration exactly including quench area.
The allowance for the use of aftermarket forgings vs. OE castings
does not permit alternate piston dome designs. This allowance
does not permit alternative ring configurations.
T. Rotating and reciprocating parts may be balanced but not lightened.
U. Intake and exhaust ports and manifold openings may be
matched provided no change is made more than one inch from
the port/manifold interface. Material may be removed to facilitate
port matching, but no material may be added.
V. Any transmission oil cooler may be used.
W. The engine cylinder head(s) may be milled only to that amount
specified in the manufacturer’s workshop manual. If no amount
is specified then a maximum of 0.010 in. may be milled.
X. Axle/halfshaft and driveshaft retention/location devices may be
installed for safety reasons to control the motion of attached
shafts upon the failure of a coupling or universal joint. They
may serve no other purpose. This allowance does not include
“C-clip eliminators.”
Y. Any crankshaft damper or pulley may be used. SFI-rated dampers
are recommended. Supercharged cars may not change the
effective diameter of any pulley which drives the supercharger.
Z. Any accessory pulleys and belts of the same type (e.g. V-belt,
serpentine) as standard may be used. This allowance applies to
accessory pulleys only (e.g., alternator, water pump, power
steering pump, and crankshaft drive pulleys). Supercharged
cars are excluded from this allowance. Alternate pulley materials
may be used. Idler pulleys may be used for belt routing in place
of items which the rules specifically allow to be removed, such
as smog pumps and air conditioning compressors. They may
serve no other purpose.
AA. Camshafts and related parts must remain standard except that
alternate cam drive pulleys or gears may be used to adjust cam
timing if no variable cam and/or valve timing system exists as
standard. Type of cam drive (chain, belt, gear) must remain as
standard. Alternate parts of the same general type (e.g. roller
chain in place of “silent” chain) may be substituted. Mating parts
(block, heads, covers, retainers, etc.) may not be altered. Vehicles
equipped with a variable cam and/or valve timing system
as standard may use alternate computer calibration to adjust
cam and/or valve timing but may not change or substitute cam
drive components (hardware).
97
15.11 OUT-OF-PRODUCTION CARS
Where a car is out of production and the manufacturer is either out
of business, stocks no parts or no longer has a required part, a part
of any origin but as similar as possible to the original may be
substituted. The entrant must be prepared to show documentary
evidence that one of the three circumstances above applies and that
the substituted part is as similar as possible under the
circumstances. Substitute parts which provide improvements in
performance (e.g. superior gearing, lighter weight, better camshaft
profile, etc.) are not permitted under this allowance.
[/code]

 

The compression difference is in the LS6 heads, which have a VERY slightly smaller combustion chamber than the LS1 heads.

Choosing an LS6 motor over an LS1 motor and having to pay a price difference isn't a great idea, since the only real performance difference (or any REAL differences at all) between the 01+ LS1 and the LS6 motors are only in the heads (slight) and cam (very slight). If you put a mild cam in the LS1, you'd run circles around the LS6...

As far as class rules go.. all they'd have to do is look at the casting number on the head and know that they are LS6 heads and were not offered on any F-body for that year... or any year.

 

Definitely wouldn't pass those rules as Mike stated because of the heads and cam being LS6 pieces.

 

Great, I'll try to dig up the LS6 head casting number and the casting number location and go from there

Edit: You think there's any way I can get these answers 'certified' by someone official, say Scott Settlemire? Doesn't he have an account here?

 

LS6 heads are casting number 243. It should be on the front of one of the heads (if memory serves).

2001-2002 (possibly some 2000) LS1 heads are a 241 casting number.

1998 LS1 heads are 88x casting numbers.

1999 I can't remember. Edit 1999-2000 were 853 castings.