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

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

Post by SSpeedracer » Mon Apr 16, 2018 8:46 pm

Silversled wrote:
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.
Thanks for your input.

I'm planning on setting the L77 up like a LS3, 6200 rpms. However, I did not consider the valves.

My plan is LS3 Cam, blue valve springs, DOD delete with new lifters, maybe injectors but haven't calculated that yet. I'll block off oil ports like you suggest.

Then I was going to tune the fuel/timing/trans using a SS for baseline.

I'm not planning on flogging the caprice. I've got a blown ls1 fbody for that.


Is there any reason to think a 6200 rpm fuel cutoff is too high for the L77 valves?
Any advice on switching out rockers or other parts (135k miles)?
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 » Tue Apr 17, 2018 3:08 am

SSpeedracer wrote:
Silversled wrote:
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.
Thanks for your input.

I'm planning on setting the L77 up like a LS3, 6200 rpms. However, I did not consider the valves.

My plan is LS3 Cam, blue valve springs, DOD delete with new lifters, maybe injectors but haven't calculated that yet. I'll block off oil ports like you suggest.

Then I was going to tune the fuel/timing/trans using a SS for baseline.

I'm not planning on flogging the caprice. I've got a blown ls1 fbody for that.


Is there any reason to think a 6200 rpm fuel cutoff is too high for the L77 valves?
Any advice on switching out rockers or other parts (135k miles)?
If you are raising the redline I'd definitely consider updating the valve spring rate to get better valve control. Better yet, since you have the heads off, refresh them with new intake valves from the standard LS3 like the SS (exhaust valves are the same). When tuning, I'd be watching for signs of valve float as I creep up on redline. Initial signs of this are erratic but small fluctuations in MAF readings.

I'd keep the stock injectors for now and monitor duty cycle. If you are tuning just for pump gas, the stock injectors will have plenty of headroom since they are intended to handle up to E85 volume levels. Stock rockers will be fine for a stock cam and 135K miles is not a heck of a lot for this engine. If you're concerned about them then at least change out their bearings. I used bronze bushings but its a personal choice.
2014 Chevrolet Caprice PPV
2014 Chevrolet Stingray Z51
2016 AMG C63
2015 BMW X5 iDrive 50i

s/c'd cav
Posts: 505
Joined: Mon May 30, 2016 8:12 am
Location: PHOENIX AZ

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

Post by s/c'd cav » Tue Apr 17, 2018 6:05 am

my old l76 used to spin over 7k , with double spring and a big ass cam , my stock ls3 spins 6500

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