LS3 cam, DOD block off or just HPTune off?

Tech discussions on the L77 6.0L V8.
SSpeedracer
Posts: 50
Joined: Tue Mar 13, 2018 11:34 pm

LS3 cam, DOD block off or just HPTune off?

Post by SSpeedracer » Wed Apr 11, 2018 10:39 pm

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.
2016 Caprice

lastcall190
Posts: 201
Joined: Mon Sep 11, 2017 10:17 am
Location: North Jersey

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

Post by lastcall190 » Wed Apr 11, 2018 11:27 pm

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
2012 Caprice
DOD Delete, LS9 Cam, Pat G tune, Magnaflow G8 Exhaust

2008 CVPI
163k miles and counting

SSpeedracer
Posts: 50
Joined: Tue Mar 13, 2018 11:34 pm

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

Post by SSpeedracer » Thu Apr 12, 2018 12:10 am

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.
2016 Caprice

kevink
Posts: 333
Joined: Sun Aug 09, 2015 5:55 pm

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

Post by kevink » Thu Apr 12, 2018 12:49 am

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 Thu Apr 12, 2018 12:56 am, edited 1 time in total.

lastcall190
Posts: 201
Joined: Mon Sep 11, 2017 10:17 am
Location: North Jersey

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

Post by lastcall190 » Thu Apr 12, 2018 12:53 am

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

-J
2012 Caprice
DOD Delete, LS9 Cam, Pat G tune, Magnaflow G8 Exhaust

2008 CVPI
163k miles and counting

xcidmigs
Posts: 682
Joined: Sat Feb 14, 2015 2:12 am
Location: SE PA

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

Post by xcidmigs » Thu Apr 12, 2018 2:14 pm

Or you could just man up and use DOD with that cam like I am!!! :shock:

SSpeedracer
Posts: 50
Joined: Tue Mar 13, 2018 11:34 pm

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

Post by SSpeedracer » Thu Apr 12, 2018 9:45 pm

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.
2016 Caprice

Silversled
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Joined: Fri Aug 12, 2016 12:13 pm
Location: Tampa, FL

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

Post by Silversled » Thu Apr 12, 2018 10:38 pm

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.
2014 Chevrolet Caprice PPV
2014 Chevrolet Stingray Z51
2016 AMG C63
2015 BMW X5 iDrive 50i

SSpeedracer
Posts: 50
Joined: Tue Mar 13, 2018 11:34 pm

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

Post by SSpeedracer » Fri Apr 13, 2018 8:46 am

Yes, this is what I'll do. thanks
2016 Caprice

Silversled
Posts: 263
Joined: Fri Aug 12, 2016 12:13 pm
Location: Tampa, FL

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

Post by Silversled » Sun Apr 15, 2018 1:39 pm

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.
2014 Chevrolet Caprice PPV
2014 Chevrolet Stingray Z51
2016 AMG C63
2015 BMW X5 iDrive 50i

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