LS3 cam, DOD block off or just HPTune off?

Tech discussions on the L77 6.0L V8.
SSpeedracer
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Joined: Tue Mar 13, 2018 6:34 pm

LS3 cam, DOD block off or just HPTune off?

Post by SSpeedracer »

I'm installing a slightly used LS3 cam/spring set with new lifters. I already have HPTuners for other cars and would prefer to just tune 'off' the DOD system. Or, is it required to mechanically block off? Thanks.
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lastcall190
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Re: LS3 cam, DOD block off or just HPTune off?

Post by lastcall190 »

Are the new lifters non-DOD? If so, you are already blocking it off so to speak, and just have to use HPT for the tuning portion.

If that's not the case, I'm not entirely sure what you're asking. I *believe* I've seen a post where someone (here or g8 board) used the LS3 cam with DOD.

-J
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2008 CVPI

Both gone but not forgotten...
SSpeedracer
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Joined: Tue Mar 13, 2018 6:34 pm

Re: LS3 cam, DOD block off or just HPTune off?

Post by SSpeedracer »

yes. Im using new non-DOD lifters. Thanks.

I saw the ls3/dod discussion. I thought the l77 cam had smaller lobes for the DOD lifters compared to regular hydraulic lifters. in other words the cams shaft has different grind for each cylinder.
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kevink
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Re: LS3 cam, DOD block off or just HPTune off?

Post by kevink »

You should "block it off" with a non-dod valley cover or plug the passages in the block. You'll still have to tune it out with HP Tuners.
Last edited by kevink on Wed Apr 11, 2018 7:56 pm, edited 1 time in total.
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lastcall190
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Re: LS3 cam, DOD block off or just HPTune off?

Post by lastcall190 »

Right, forgot about the non-DOD cover, whoops.

-J
2012 Caprice
2008 CVPI

Both gone but not forgotten...
xcidmigs
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Re: LS3 cam, DOD block off or just HPTune off?

Post by xcidmigs »

Or you could just man up and use DOD with that cam like I am!!! :shock:
SSpeedracer
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Re: LS3 cam, DOD block off or just HPTune off?

Post by SSpeedracer »

L77 : LS3

Duration @ .050 in. (int./exh.)
196°/208° : 204°/211°

Valve Lift (int./exh.)
0.478 in./0.466 in. : 0.551 in./ 0.525 in.

Lobe Separation
116° : 117°

Prior to me owning, at 109K miles the l77 cam and lifters failed and were replaced with new parts.

Do you think the added lift of the LS3 cam and rate of blue valve springs will accentuate the stress on DOD lifters? Causing earlier failure? L77 rev limit is lower than LS3 perhaps due to lifters.

Why would GM detune the L77 unless it was a result of DOD reliability? I'd imagine if they could manufacture a reliable LS3 DOD system they would have. Maybe not.

Regardless, the discussion has made me re-evaluate the cam swap for now.
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Silversled
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Re: LS3 cam, DOD block off or just HPTune off?

Post by Silversled »

If the LS3 cam is what you want, use standard LS7 style hydraulic lifters with the blue beehive GM springs. Since the intakes and heads are off, pull the valley tray and block off the valley pillars if you want to extra measures. Double check the pushrod length since you don't know what was done previously to the block or heads. Disable the DOD in HPtuners while you are in there tuning for the new cam. You are golden.
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SSpeedracer
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Re: LS3 cam, DOD block off or just HPTune off?

Post by SSpeedracer »

Yes, this is what I'll do. thanks
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Silversled
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Re: LS3 cam, DOD block off or just HPTune off?

Post by Silversled »

SSpeedracer wrote:Yes, this is what I'll do. thanks
If you are going to be beating on your car and bouncing it off redline, I would also recommend uprating the springs to some PAC or other beehive style. They are cheap and the extra spring rate will help the heavier valves in our heads from floating. Don't bother with dual springs unless you are going to a much higher lift with an aftermarket cam. Good luck.
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2014 Chevrolet Stingray Z51
2016 AMG C63
2015 BMW X5 iDrive 50i
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