Sorry this has probably come up a few times but most of the information i find on this subject seems to vary between site/person.

the 01 Z as you all know had the 385hp and the notorious oil blow-by but other than that what was changed for the 02-04 405hp LS6? anything changed other then to add the 20hp? Clutch, gears...etc,etc.

 

The notorious Oil problem was not all that notorious. It effected early production cars and to my understanding was not really a significant amount of Oil loss. Mid and Later models did not have this issue.

HUD was added as an option you could get on the 02 Z06.

If you take a look at the Corvette Black Book it details the changes nicely. Stronger LS6. modifications to the Cats, increased MAF sensor flow, Cast Spun wheels , and a few other upgrades.

I own a MAY 02 built 01 and there is NO oil consumption issue. There is a GAS consumption issue when I run at 5000 RPM but other than that zero complaints.

The changes from model year to model year are well documented and there should be no differences of opinion from person to person or site to site, unless of course someone is guessing.

 

Differences:

2001
* Return to 28# injectors for all models.
* Second Generation Active Handling
* Nassau Blue discontinued
* Alternator 'clutch' pulley added on A4 cars
* New soundproofing + foam in all cars
* Smaller keyfob
* Electrochromic dimming rearview and driver's mirrors
* Lighter AGM battery
* Thickness + Material in Convertible change
* Chrome exhaust tips for coupe + Convertible
* 85MM MAF with integral temp sensor (versus 74mm with separate plug for IAT)
* LS1 cam profile changed to: .500/0.500, 198/208 on 115.5LSA (From: 0.472/0.479, 202/210 on 117)
* All Corvettes now have the LS6 intake manifold
* All Corvettes now have the LS6 engine block (windage passages in block), which includes a beefier oil pump.
* LS1 changes result in new output of 350 HP @ 5200 RPM and 375 Ft Lbs of torque @ 4400 RPM (MN6)
* Hardtop/FRC discontinued
* Stronger synchros in all transmissions
* Exhaust manifolds revised (5hp regained) - thin wall cast replacing SS manifolds
* Metal valvestem caps (late year)
* Torque Tube changed from metal-matrix composite to aluminum alloy 6061, increased in diameter from 55 to 63 mm.
* Driveshaft couplings have also been upgraded on manual-equipped models for additional strength and durability
* Introduction of the Z06, which has as differences:
* Hardtop body style
* Rear brake ducting
* Screened inlets on front fascia, without foglights
* F1 Supercar tires 265-17 front, 295-18 rear, on 17x9.5 and 18x10.5 (one inch wider, respectively
* New LS6 top-end with new style head design (10.5:1 compression, 64cc chamber), LS6 cam (0.525/0.525, 204/211 on 116) - 385hp
* M12 transmission with shorter gearing (1-2-3 analagous to MN6 with 3.90 rear diff
* Titanium exhaust system
* Lightweight windshield
* New, stronger clutch with redesigned master + slave cylinder
* Stronger rear differential (shotpeened ring gear)
* Red brake calipers (otherwise identical)
* Transmission overtemp warning light on DIC
* 6500 redline gauges with special checkering + Z06 font
* Redesigned PCV system to help combat oil burning
* Red LS6 Fuel Rail Covers (FRC's)
* FE4 Z06 suspension - uprated springs, bars (30mm/23.6mm), shocks (note front spring and rear bar same as Z51)

2002
* Z06 Changes:
* Z06 LS6 cam changed to: 0.551/0.547, 204/218 on 117.5
* Less restrictive intake airbox lid
* Descreened MAF
* Removal of pup-cats (total with changes = 405hp)
* Z06 shocks revised with less rebound for better launching
* Z06 brake pads revised for better stopping (generate more dust)
* Lighter, sodium filled valves w/ stronger valve springs
* Higher tension rings installed to prevent oil burning problems
* Slight piston redesign *
* Clutch strength upgraded.
* HUD available on Z06 (not avail '01 model year)
* Wheel supplier changed to Speedline, moved from forged to cast. Weight nearly identical
* Electron Blue color offered
* Steel endlinks changed to aluminum


Oil Consumption Issue:

1999 - 2002: Service Bulletin: Higher Than Expected Oil Consumption
Subject: Higher Than Expected Oil Consumption (Replace Rings and Engine Valley Cover)
Source: Chevrolet Dealer Technical Service Bulletin
Number: 01-06-01-023A

Condition
Some owners may comment on higher than expected oil consumption. When checked, the oil
consumption could be in the range of 400-600 miles per quart (700-1000 km/L).
On the LS6 engine only, the technician may find oil behind the engine throttle plate and in the
intake manifold.

Cause
The cause for this condition may be an interaction between the piston rings and the cylinder
bore in vehicles that are operated at higher RPMs -- typically manual transmission vehicles
driven in a manner where the engine is frequently or consistently operating at greater than 3200
RPM.
On the LS6 engine only, the engine has a unique aluminum valley cover that has composite oil
separating baffles and PCV plumbing incorporated. In some cases, the PCV baffle may not be
properly sealed to the valley cover, causing oil to enter the PCV system.

Correction
On the LS6 engine only, replace the engine valley cover if oil is found behind the throttle body
or in the intake manifold before replacing the piston ring. Refer to Engine Valley Cover
Replacement in the Engine Mechanical - 5.7L subsection of the Corvette Service Manual.
A new set of piston rings is currently available through GMSPO. The new rings are part of a complete piston ring kit. Install only the
number 2 compression ring and the oil expander ring from the piston ring kit. All other rings in the piston ring kit should be
discarded. The original number 1 compression ring and the oil ring rails should be re-used in their original positions on the piston. All
pistons should be used in the same cylinder bore.

 

now thats an answer !

 

wow thank you that covers everything. i really appericate the help guys.