98onyxss

Can you run an L76 with VVT/DOD without a computer? I don't want to do a cam swap and delete everything yet, so I'm wondering if the default for the engine if the electronics portion isn't hooked up will allow the engine to run like normal.

98onyxss

Buehler?

speedtigger

iTrader: (16)

You might ask this question is the gen IV section internal engine section. The only thing I have read is guys wanting to eliminate those features. I know Texas Speed sells a kit to eliminate the DOD and VVT.

UOP

I'm new to the LSx world, but I am also using an L76 in my build. My research suggests you can't run a carb with the VVT cam due to it being either too far advanced or retarded in default. In that case, it pretty much negates having to worry about the AFM/DoD part because if the VVT needs to be removed you can't use that cam anyway. Looks like the cam needs to be swapped for a 3 bolt, non VVT cam. Maybe a stock LS3 cam. You can buy a kit to remove the VVT and AFM/DoD (Tick Performance is who I've looked at) for about $550.

98onyxss

The guys in the internals section said to ask over here! Lol.

Ive got a buddy that I'm going to get an LS3 cam from and the rest of the hardware needed to get rid of VVT and AFM. I was just wondering if I could get away with firing this one up as it sits now, I don't think the AFM will be a problem, but the VVT may. I wonder how the phaser is controlled, and if you can't get away with just leaving it unplugged, maybe it can have a specified voltage applied to it to keep it at a certain position.

dogsballs

in aus in 2006, they released some of the engines with DOD, but there were no electronics to activate them. the engine will operate as normal, however the DOD lifters are a little dodgy and any decent revs will have valve float. there is no VVT as such, just DOD. the lobes on the DOD sections have fractionally less lift. for the sake of a cam and one bank of ls7 lifters, pretty easy upgrade.

98onyxss

I'm not looking to tear into this motor yet. I might have a line on some ls3 stuff to swap everything though. I'm also trying to talk to mast about either making myself, or having them make a module to control the vvt. The dod seems easy enough to control if I wanted, but I couldn't shut off the fuel with the carbs.

3pedals

iTrader: (3)

I ran my LY6 carb'd with the stock cam.
I simply swapped:
- VVT top cam gear to a single bolt non-vvt top gear
- matching non vvt cam bolt
- non-vvt front timing cover
You will need these parts later anyway when you swap cams.
the stock cammed LY6 pushed my camaro to 12.59 @109

The VVT, all you need is a PWM output and you can work the VVT.
I personnally dont think its worth the hassle, because once you start getting aggressive with the cam/valvesprings, and going for a bit more rpm(7000+), the cam phazer becomes an unpredictable variable that can allow piston to valve contact.

speedtigger

iTrader: (16)

You have had so many iterations of your car, I think it would be great to see an anthology of each set up and what it ran. That would be a cool thread so people could see what is possible for different approaches.

98onyxss

As long as you keep a stock cam, you shouldn't have to worry about clearances right? And I wont be spinning it to the moon. I think a little module to control the cam phase either off of RPM or set positions would be pretty sweet. Degreeing a cam at the track based on your conditions is a lost art. Imagine how easy it could be for the carb guys with something like that.

Still haven't heard back from MAST. Im going to give them a call tomorrow and see if they can help out.

dogsballs

you're happy to make a module and/or chase mast to make one, but not pull the heads off? not my way of thinking.

these are very basic engines to get hp out of with minimal mods/cost

98onyxss

$50 bucks and a few hours of work is easier than pulling the heads, new cam, new lifters, front cover, top cover, pulling the balancer, new timing gear, new lifter trays, pushrods, gaskets, etc. This motor is a temporary one and I don't feel like doing anything to it that I don't have to.

WE TODD DID

iTrader: (2)

It will run on 4 cylinders if you don't disable the dod. The vvt will stay standing at normal, no issues there.

98onyxss

From what ive seen, the default is 8 cylinder. The solenoids require power to deactivate the four cylinders. And the vvt will be in the full retard position......never go full retard.

98onyxss

Im gonna put the info I find in this thread. This piece states that the cam park is in the full advance position.

"The camshaft position (CMP) actuator system is used for a variety of engine performance enhancements. These enhancements include lower emission
output through exhaust gas recirculation (EGR) control, a wider engine torque range, improved gas mileage, and improved engine idle stability. The
CMP actuator system accomplishes this by controlling the amount of intake and exhaust valve overlap. For the 6.0 liter (LY6, L76) and the 6.2 liter
(L92) engine, the Park position for the CMP actuator and camshaft is 8.5 degrees before top dead center (BTDC) or 17 crankshaft degrees BTDC. The
engine control module (ECM) can only command the CMP actuator to retard the valve timing from the Park position or advance the valve timing back to
the Park position. The total range of valve timing authority is 31 degrees camshaft rotation, or 62 degrees of crankshaft rotation. The control range is
from the Park position of 8.5 degrees camshaft or 17 degrees crankshaft BTDC, to 22.5 degrees camshaft or 45 degrees crankshaft after top dead center
(ATDC)."

3pedals

iTrader: (3)

^That is correct. Tge vvt locks 8.5* advanced with no power to it's solenoid

98onyxss

Getting a hold of Mast is pretty damn difficult. I left a couple of messages over the last week or so for the tech guy and finally talked to one of the sales guys. They don't make anything like what I'm looking for, but have had the request before. The info I need now is for the control of the solenoid magnet. How many hz is the rest position, and how many for the full open?

I pulled the magnet/solenoid and am giving it to a buddy who saI'd it'll be easy to figure out. (He will be the one building the module.) But it would be nice to find the spec data somewhere through delphi or whoever.

Part numbers for the magnet are
12585995
06041804390

Also another piece of info that may come in handy down the road...
Static Test
Test for 5.9-6.9 ohms of resistance at 20°C, or 68°F between the solenoid control terminal 2 and
the low reference terminal 1 at the CMP actuator solenoid.
Dynamic Test
Important: Do not allow electrical current to flow through the CMP actuator solenoid for more
than 1-2 seconds, or damage to the solenoid may occur.
Point the CMP actuator solenoid vertically, towards a shop towel. Connect one end of a fused
jumper wire to the CMP actuator solenoid control circuit terminal 2 and 12 volts. Connect a second
jumper wire to the low reference circuit terminal 1 and momentarily connect to ground. The CMP
actuator solenoid should immediately extend.

98onyxss

More info


A CMP actuator dynamically changes valve timing events relative to piston timing by controlling camshaft position. This is sometimes referred to as variable valve timing or camshaft phasing. Variable valve timing or camshaft phasing does not change duration or lift.



By advancing camshaft timing, an improvement in low end torque can be achieved.
By retarding camshaft timing slightly, an improvement in high end power can be achieved.
By retarding camshaft timing significantly, an improvement in light load fuel economy can be achieved.
There are 5 cavities divided by vanes within the CMP actuator.



When oil is directed to the advance cavities (1), the camshaft timing is advanced.
When oil is directed to the retard cavities (2), the camshaft timing is retarded.
When oil is directed to both cavities, the camshaft is held stationary.






The 6.0L L76 and 6.2L L92 CMP actuator has a 62 degree range of authority. With the engine not running and no engine oil pressure to the CMP actuator, the high tension spring positions camshaft timing at the 17 degree advanced park position. During normal engine operation and based on performance requirements, the ECM may adjust camshaft timing, as required, within a range from 17 degrees advanced to 45 degrees retard.

98onyxss

I think im confused on what Im looking for. Its not HZ, but % of modulation that I need to know. Im guessing that the max extension for the solenoid is less than 100% cycle since 12v for more than 2 seconds can damage the solenoid.

3pedals

iTrader: (3)

Your looking too deep. Comp cams sells phazer limiters that keep the degress of operation within reason. With a pulse width modulated output, and some experimentation, you should be able to find an rpm where the engine responds to retarding the cam from its resting position. Then keep adding pulse width untill it doesnt pick up on the top end.
Your going to want to hit up a dyno for this testing......
Much easier and probably cheaper to just eliminate the vvt.