Smallest Comp cam VVT cam clearance for L99.

[InFiD3ViL]

Can any of the pros chime in here?

Assume cam swap was never the intention in this scenario. This is a unique example since most people just go full cam swap if they have to pull the heads.

Question: Let's say I had an AFM lifter go bad. But I did NOT want to replace it with another AFM lifter. I simply want to swap out and replace with 16 all new LS7 lifters. My intention was never to cam swap, only to replace the lifters with something more reliable. I would also be doing a full AFM/DOD delete at this point and changing to new springs, irrelevant which type at this point, as that's another can of worms.

Is the stock L99 VVT cam still useable at this point? Will it work fine with a DOD delete and LS7 lifters only? Or would I need to change it out for a VVT only cam (VVT minus the DOD)

Because if the cam is still useable, this member can do the DOD delete, including LS7 lifter upgrade, springs, hardware, etc - and just put his stock cam back in. This would keep him exactly with what he wants.

Originally Posted by WoodBoss

If you don't want to use a range device just get an SCT X4 and custom tune from DynoSteve download the tune and AFM is tuned out and you still have access to the ODB port. Changing a cam and all that stuff is not needed and stiffer springs now you have to replace them every 25k miles.

He wants to replace the AFM lifters completely, and was told he cannot keep the stock VVT cam (I am not sure on this). He just wants a VVT only cam, no AFM/DOD at all. I think its more of a maintenance/reliability thing, rather than performance.

What I don't understand is why he would need to run such stiff springs for a nearly stock cam. That is unnecessary and, like you said, would require maintenance every 25k or so....for a stock-ish cam. What's the point in that?

Wouldn't this be the perfect build for a premium beehive upgrade rather than super stiff dual springs?

Originally Posted by 0331Marine

Honestly wouldn't waste the time or money. That's alot of work for very little gain.

It would make sense for someone with a high mileage L99, still running stock AFM lifters. Eventually, you want to replace those AFM lifters.

Myself, my L99 has 122k miles and I already feel like I am on borrowed time with the stock lifters.

[Tran2la]

Originally Posted by xc_SS/RS

you'll need new valve springs and i would go with psi 1511ml springs over anything from pac. ls3 springs might work as well if you are looking to stick with a budget, just unsure of the total lift they can handle.

not sure on the VVT parts but definitely swap the afm lifters with LS7 lifters

Thank you for the spring recommendation. They seem to handle .625 lift.

I also called up Comp cams again and they said cam phaser limiter required. They also stated that I could get the cam I was interested in custom made with a 117 LSA. Something to think about.

Called up GPI and they confirmed anything over .550 lift needs to limit the cam phaser or interference may happen. They too stated that they have a cam that was less than the SS1 that might fit my needs. They were going to let me know of a custom grind that may work for my goal.

[jc615]

Originally Posted by InFiD3ViL

Can any of the pros chime in here?

Assume cam swap was never the intention in this scenario. This is a unique example since most people just go full cam swap if they have to pull the heads.

Question: Let's say I had an AFM lifter go bad. But I did NOT want to replace it with another AFM lifter. I simply want to swap out and replace with 16 all new LS7 lifters. My intention was never to cam swap, only to replace the lifters with something more reliable. I would also be doing a full AFM/DOD delete at this point and changing to new springs, irrelevant which type at this point, as that's another can of worms.

Is the stock L99 VVT cam still useable at this point? Will it work fine with a DOD delete and LS7 lifters only? Or would I need to change it out for a VVT only cam (VVT minus the DOD)

Because if the cam is still useable, this member can do the DOD delete, including LS7 lifter upgrade, springs, hardware, etc - and just put his stock cam back in. This would keep him exactly with what he wants.

Talk to Frank, believe he is using the stock cam still with upgraded lifters. Edit - Nevermind, he is M6/LS3 car

[Tran2la]

Originally Posted by InFiD3ViL

Can any of the pros chime in here?

Assume cam swap was never the intention in this scenario. This is a unique example since most people just go full cam swap if they have to pull the heads.

Question: Let's say I had an AFM lifter go bad. But I did NOT want to replace it with another AFM lifter. I simply want to swap out and replace with 16 all new LS7 lifters. My intention was never to cam swap, only to replace the lifters with something more reliable. I would also be doing a full AFM/DOD delete at this point and changing to new springs, irrelevant which type at this point, as that's another can of worms.

Is the stock L99 VVT cam still useable at this point? Will it work fine with a DOD delete and LS7 lifters only? Or would I need to change it out for a VVT only cam (VVT minus the DOD)

Because if the cam is still useable, this member can do the DOD delete, including LS7 lifter upgrade, springs, hardware, etc - and just put his stock cam back in. This would keep him exactly with what he wants.




He wants to replace the AFM lifters completely, and was told he cannot keep the stock VVT cam (I am not sure on this). He just wants a VVT only cam, no AFM/DOD at all. I think its more of a maintenance/reliability thing, rather than performance.

What I don't understand is why he would need to run such stiff springs for a nearly stock cam. That is unnecessary and, like you said, would require maintenance every 25k or so....for a stock-ish cam. What's the point in that?

Wouldn't this be the perfect build for a premium beehive upgrade rather than super stiff dual springs?



It would make sense for someone with a high mileage L99, still running stock AFM lifters. Eventually, you want to replace those AFM lifters.

Myself, my L99 has 122k miles and I already feel like I am on borrowed time with the stock lifters.

Finally!! Someone who understands my goal!!! Thank you.

Yes its for reliability. This engine is going to be used a lot. 2000+ miles a month and I don't want to deal with lifters that has a high failure rate in the engine.
This engine has 55,000 miles and I don't even want to chance pulling the heads and doing all that its needed after its installed in my car. I prefer to do it now while its sitting in the Camaro subframe on the floor.

The cam I am looking at has a higher lift. But it is a baby cam by the standards of most cams people get. Because of this higher lift, the springs that are currently in the L99 engines would probably valve float in higher rpm. The max lift of the L99 factory cam is .500. So you can expect that the max lift that the spring may handle would be in the .525-.550 range. The cam I am looking at, despite it being small, has a slightly higher lift than the Stock LS3 cam. That's why I was interested in better springs.
I used the LS3 cam as the model to find a VVT cam replacement and that is how I came up with the Comp cams Camshaft.

LS3 specs = 204/211 duration. .551/.525 Lift 117* lobe separation angle.
Comp cam = 210/224 duration .556/.568 Lift 114* Lobe separation angle.
L99 specs = 195/201 duration .500/.492 Lift 115* Lobe separation angle.

So as you can see, the LS3 cam is what I looked at as a model to find a comparable cam. Why the LS3? Because its a factory camshaft with great idle characteristics and it has good power. So I thought why not keep VVT, which is beneficial, and have the LS3 cam specs. Almost like have my cake and eat it too.

From my research, you cant just shut off AFM and ride with the stock cam and stock AFM lifters. Its best, in a reliability standpoint, to take it all off the engine.

[Royal Tiger]

I’m confused over the 25k miles comment. So ANY new cam will need the lifters/springs serviced every 25k mile’s??

[jc615]

Lifters will be fine 99.9% time at 25k miles and further. Springs are recommended to be replaced at 25k for high lift cams.

[InFiD3ViL]

Originally Posted by Royal Tiger

I’m confused over the 25k miles comment. So ANY new cam will need the lifters/springs serviced every 25k mile’s??

I have never heard of that for lifters, have for the stiffer springs.

[Pro-tuned]

The lifter logic makes sense but at the same time there will be other risks to address. Also the VVT is not exact science; through proper tuning (which is required for DOD delete) there is enhanced flexibility, modeling, and the ability to smooth out transitions. Taking a stock L99 log and apply it in modeling then it becomes clear that perhaps VVT isn’t so efficient in a stock state.

[Avenging Orange]

I'm still confused. Correct me if I'm wrong....but aren't you simply describing an LS3 conversion? Which sounds like the easiest, safest option.

[Pro Stock John]

Go with GPI SS1, has a good small lope. Go on Youtube for videos. Also makes 440rwhp.

I been dailying their VVT SS3 for a few years, LS7 lifters.

The phase shifter thing is a not a big deal to install.

[Tran2la]

Originally Posted by Pro Stock John

Go with GPI SS1, has a good small lope. Go on Youtube for videos. Also makes 440rwhp.

I been dailying their VVT SS3 for a few years, LS7 lifters.

The phase shifter thing is a not a big deal to install.

I have heard SS! and its too much lope for me at the moment. No lope would be ideal. I want stock idle. Why isn't there a cam with No DOD grind and no lope. Why isn't there a stockish replacement?

The L99 cam has their lobes cut differently for cylinders 1,4,6,7. I would like a VVT cam with all lobes cut the same. When I refer to LS3, I'm not referring to the LS3 conversion. Just the camshaft specs. My ideal cam would be a VVT cam that was close to the LS3 specs. I'm sure that it would not be exactly the same specification in terms of duration, lift and Lobe separation because of the VVT system and how it changes valve timing in its normal engineered operation. But my ideal scenario would have it idle smooth and quiet. And if I was able to use LS3 springs, even better.

Everyone is stuck on performance and more power. For me, the engine with stock power is good n plenty.

[InFiD3ViL]

Originally Posted by Avenging Orange

I'm still confused. Correct me if I'm wrong....but aren't you simply describing an LS3 conversion? Which sounds like the easiest, safest option.

He is and he isn't.

With an LS3 conversion, he would lose VVT entirely. What he wants is basically an LS3 conversion, except keeping the VVT.

It is exactly what the VVT cammed guys do, EXCEPT he wants to stay with a stock VVT cam. But there is confusion whether or not the stock VVT cam is useable since it was also designed for an engine with active DOD.

[Tran2la]

Originally Posted by InFiD3ViL

He is and he isn't.

With an LS3 conversion, he would lose VVT entirely. What he wants is basically an LS3 conversion, except keeping the VVT.

It is exactly what the VVT cammed guys do, EXCEPT he wants to stay with a stock VVT cam. But there is confusion whether or not the stock VVT cam is useable since it was also designed for an engine with active DOD.

Yes I would like the stock cam remade with all 16 lobes the same. Basically take lobes for cylinders 1,4,6,7 (AFM lobes) and make the same as lobes 2,3,5,8 (Non AFM lobes). I feel that would probably be the simplest. But if it was possible to grind me a stock camshaft with all the lobes with a bit more duration and lift like the LS3, than it would be basically a LS3 with VVT.

[InFiD3ViL]

Originally Posted by Tran2la

Everyone is stuck on performance and more power. For me, the engine with stock power is good n plenty.

Yes they are, but you kinda can't blame them.

As I said earlier, this is a unique example. Almost anyone that takes the heads off of an L99 is going to swap the cam, simple as that. Most don't want to go through all that work without the reward at the end...the power.

Tran2la, when you get this job done, PLEASE update this thread or post a new one. I would love to see how it comes out.