Removing DOD hardware & fitting a larger camshaft

[Crazy Paul]

The L76 6.0 engine is an LS2 engine block with good flowing L92 cylinder heads, a 90mm LS3 intake manifold and 40ish lb/hr LS7 injectors. There's lots of performance potential there in a Pontiac G8-GT, unfortunately in stock form it's also fitted with AFM or Displacement on Demand hardware.

This AFM hardware includes a tiny camshaft(200/208......0.472"/0.479") which has a different grind on cylinders 1, 4, 6 and 7 than the "normal" cylinders. Also fitted to cylinders 1, 4, 6 and 7 are De-Ac lifters , while the remaining cylinders use conventional lifters.

Those of you who are not concerned by powertrain warranty implications and wish to free up the performance potential of the 6.0 L76 may at some stage wish to remove the AFM Hardware and install a performance camshaft.

Here's the hardware involved :

[Crazy Paul]

1) Custom Camshaft. This will be the same as any normal LS1 type camshaft with a 3 bolt core from manufacturers such as Comp. Typically you'd wan't something with a split favouring the exhaust but with minimal overlap.
Something like below will normally achieve close to 450rwhp in this combo.
224@.050int, 230@.050exh
.581int, .590exh LSA 114
[Note PTV clearance must be checked in every case]




2) 12586481
Camshaft Sprocket
• Fits LS1, LS2 and LS6
• 4X camshaft gear
• 3-bolt design;
uses (3) bolts P/N 12556127

3) 12588670
LS2 Timing Chain Dampener
• Production LS2 Dampener
• For use with standard oil pumps
Re-use the 2x fasteners from the L76 chain tensioner.

[Crazy Paul]

4) Valve Spring Kit (typically dual spring) to match or exceed valve lift.
Example:
Patriot Gold .650" Lift Dual spring Kit PAT8401




5) Chrome Moly Pushrod Kit. Consult with your engine builder to determine the correct length of pushrods....this will depend upon the base circle of the chosen camshaft & other possible geometry changes such as head gasket thickness and any head milling.

Example:
Comp Cams CC7955-16 7.400" 5/16" 0.080"WT





6) Valve Lifters

Example:
12499225
LS Series Camshaft Lifter Kit
• Set of 16 lifters for LS series engines
• Same lifter used in LS2 and LS7

or

88958689
Racing Hydraulic Roller Lifter Kit
• As developed by GM Racing and GM Powertrain
• For use in Gen III and Gen IV engines where sustained
high rpm’s are typical
• Special reduced-mass internal components allow for
higher limiting speeds with aggressive camshaft designs
• Improved valvetrain dynamics and stability will improve
horsepower, and high rpm’s
• Tested to 8000 rpm in GM Racing applications
• Set of 16

[Crazy Paul]

7) 12610046
LS3, L92 Head Gasket
• Single gasket, (2) required
• For LS3 and L92 engines
• .051" thick
• 4.080" max bore
• Standard LS bolt pattern

8) 17800568
Cylinder Head Bolt Kit
• Kit of 15 bolts for LS Series engines produced from
January 2004 and later
• Bolts are 5mm shorter than previous design
(2) required

or

ARP134-3610 Hex head bolt kit, 2004 & up LS1/LS6/LS2
(1) set per engine required.




9) 12558573
LS Series Header Gaskets Pair

[Crazy Paul]

10)
12570471 LS2 Valley Cover
or
12599296 LS3 Valley plate.






Those 8x O rings underneath block off the previous oil supply from the L76 Lifter Oil Manifold Assembly to the Collapsible DOD Lifters. Some engine builders additionally like to tap threads into these galleries and plug them with (Qty 8) 1/8"NPT allen plugs.





11) PCV Hose - Dirty Air (as per LS2)
Part# for the LS2 dirty air hose is 12594779
It goes from the LS2 valley cover to the side of the intake manifold.




12) Plug (as per LS2)
*Part# for the LS2 Plug is 12579145*
The existing L76 PCV outlet on the drivers side rear valve cover needs to be plugged.



Plug....Bottom left in this pic.



13) 17803305
Lifter Guide Kit
• Includes (4x) lifter guides and (4x) bolts
• Makes for quick and easy cam swaps without having to
remove the intake manifold, valley plate or heads
• Works in Gen III and IV applications (except with AFM)

or

LS2 Lifter Guides 12595365 (Qty 4 req).




14)
12557840
Crankshaft (Harmonic Balancer) Bolt





Additional consideration should be given to the DOD oiling system.
The L76 oil pump displaces 1.24"/rev compared to non-DOD 6.0 engines (LS2 and L98) which have 0.95"/rev oil pumps.

There is also a DOD specific oil pressure relief valve inside the oil pan. When main oil pressure exceeds 55psi this relief valve exhausts excess oil to the sump.

[GRRRR8]

That about sums up all the parts have ordered!

[Steve]

Awesome post!

[EcoBrick Bob]

And... Paul does all of this up...side...down.... from Perth....AU!

I am now only dazed and confused......

Have you seen the number of posts he has on some of the other LS websites???



RRM

[Blackdevil77]

Nice post. Now that am scared out of my mind, how much would you charge to do this for me. lol. Jk. Awsome post though. When you get it done, i'd love to see some numbers and 1/4 times.

[Crazy Paul]

And... Paul does all of this up...side...down.... from Perth....AU!
I am now only dazed and confused......
Have you seen the number of posts he has on some of the other LS websites???
RRM

I deleted about 50 mostly useful posts off one board recently (oops...te-he), and I use a different username on the Aussie forums.