Converting LS3 to VVT, is it worthwhile - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

3rdgen3 · 04-23-2014, 02:24 PM

Ive tried searching the subject but everything that comes up is about converting L99 to LS3.

I know the advantages to these new VVT cams and they are really proving themselves in L99 cars..so how about converting the VVT stuff onto an LS3 with a VVT cam, like a GPI SS3 or SS4.

Excluding the AFM lifters for DOD, just swapping the front cover, cam phaser, sensor and the VVT cam itself, what else would be needed, how hard would it be.

I think this would be a great idea for anyone with an LS3 6speed car and wants to squeeze the most NA power. Whats everyones thoughts on that.

CFD · 04-23-2014, 02:30 PM

I don't see why you couldn't. You would need the needed wiring but that's not a big deal. The only thing I can see that may be a problem when using a larger VVT cam is the pistons, where they have to be fly cut there may be an issue if the piston on an LS3 is thinner, I believe it is but am not sure.

grocerygetter · 04-23-2014, 02:39 PM

Ls3 piston doesn't have the reliefs the l99 piston has. If it was me, I would leave an ls3 an ls3. Pick a proper cam grind and roll. I understand the VVT has a broader power and and has its place, but I would just roll the ls3 and out that conversion money elsewhere.

CFD · 04-23-2014, 02:46 PM

Quote:

Originally Posted by grocerygetter

Ls3 piston doesn't have the reliefs the l99 piston has. If it was me, I would leave an ls3 an ls3. Pick a proper cam grind and roll. I understand the VVT has a broader power and and has its place, but I would just roll the ls3 and out that conversion money elsewhere.

LS3's should stay LS3's, that way we auto guy's will still have the upper hand. lol

thahemp · 04-23-2014, 03:39 PM

Quote:

Originally Posted by 3rdgen3

Ive tried searching the subject but everything that comes up is about converting L99 to LS3.

I know the advantages to these new VVT cams and they are really proving themselves in L99 cars..so how about converting the VVT stuff onto an LS3 with a VVT cam, like a GPI SS3 or SS4.

Excluding the AFM lifters for DOD, just swapping the front cover, cam phaser, sensor and the VVT cam itself, what else would be needed, how hard would it be.

I think this would be a great idea for anyone with an LS3 6speed car and wants to squeeze the most NA power. Whats everyones thoughts on that.

I would say if you were in the motor anyways to stroke it or put in forged internals... go for it. Otherwise it's just more effort than it is worth. I never could get any answers as to how much flycutting it would take on the LS3 pistons to fit a worthwhile cam in there. I was gonna cut 0.080" reliefs for the intake valves, but I had no idea what kind of cam was gonna fit when I was done. Too much trial and error for my tastes.

CFD · 04-23-2014, 04:00 PM

Quote:

Originally Posted by thahemp

I would say if you were in the motor anyways to stroke it or put in forged internals... go for it. Otherwise it's just more effort than it is worth. I never could get any answers as to how much flycutting it would take on the LS3 pistons to fit a worthwhile cam in there. I was gonna cut 0.080" reliefs for the intake valves, but I had no idea what kind of cam was gonna fit when I was done. Too much trial and error for my tastes.

I don't think .080 will be enough for any significant cam. The reliefs on the L99 pistons are already fairly deep, if I remember somewhere around .100. When installing the SS4 cam I cut an additional .120, this is more than needed but with the valve train issues that pop up I wanted to play it safe. I read somewhere that the LS3 pistons are significantly thinner. If some one has a LS3 piston they could measure the thickness and that would tell a lot.

Rhino79 · 04-23-2014, 04:14 PM

The l99 has a nice exhaust relief and shouldn't need cut any more than stock already is. The intake size for our larger vvt and milled head combos need the intake cut side.

LS3 is a no go unless you go with a forged piston.

3rdgen3 · 04-23-2014, 04:20 PM

Okay, do basically this is definitely something to look into down the road if I ever end up building the bottom end.

Maybe a forged L99 piston with larger then stock reliefs instead of the LS3 flat tops. It sounds good in theory.

Thanks for the info everyone

04-23-2014, 02:24 PM	#1
3rdgen3 10-bolt Destroyer Drives: 2012 Camaro 2SS/RS - AGM, LS3/6M Join Date: Jun 2012 Location: Canukistan Posts: 860	Converting LS3 to VVT, is it worthwhile Ive tried searching the subject but everything that comes up is about converting L99 to LS3. I know the advantages to these new VVT cams and they are really proving themselves in L99 cars..so how about converting the VVT stuff onto an LS3 with a VVT cam, like a GPI SS3 or SS4. Excluding the AFM lifters for DOD, just swapping the front cover, cam phaser, sensor and the VVT cam itself, what else would be needed, how hard would it be. I think this would be a great idea for anyone with an LS3 6speed car and wants to squeeze the most NA power. Whats everyones thoughts on that. __________________ 2012 Camaro 2SS/RS - LS3/TR6060: Cam, Headers, Exhaust, Intake, Gears, Twin Disk, Suspension, Tuned - 475rwhp, 443rwtq

04-23-2014, 02:39 PM	#3
grocerygetter instigator Drives: 2020 6.2 Trail Boss, 2022 XC90 Join Date: Jan 2010 Location: 72034 Posts: 3,979 View My Garage	Ls3 piston doesn't have the reliefs the l99 piston has. If it was me, I would leave an ls3 an ls3. Pick a proper cam grind and roll. I understand the VVT has a broader power and and has its place, but I would just roll the ls3 and out that conversion money elsewhere. __________________ -John S.

04-23-2014, 04:20 PM	#8
3rdgen3 10-bolt Destroyer Drives: 2012 Camaro 2SS/RS - AGM, LS3/6M Join Date: Jun 2012 Location: Canukistan Posts: 860	Okay, do basically this is definitely something to look into down the road if I ever end up building the bottom end. Maybe a forged L99 piston with larger then stock reliefs instead of the LS3 flat tops. It sounds good in theory. Thanks for the info everyone __________________ 2012 Camaro 2SS/RS - LS3/TR6060: Cam, Headers, Exhaust, Intake, Gears, Twin Disk, Suspension, Tuned - 475rwhp, 443rwtq

04-23-2014, 02:30 PM	#2
CFD Drives: 2SS/RS L99 BLACK Join Date: Apr 2010 Location: Franklin , MA Posts: 6,696	I don't see why you couldn't. You would need the needed wiring but that's not a big deal. The only thing I can see that may be a problem when using a larger VVT cam is the pistons, where they have to be fly cut there may be an issue if the piston on an LS3 is thinner, I believe it is but am not sure.

04-23-2014, 04:14 PM	#7
Rhino79 Drives: 2010 Camaro SS L99/Auto Join Date: Jul 2011 Location: Cabot, AR Posts: 2,827 View My Garage	The l99 has a nice exhaust relief and shouldn't need cut any more than stock already is. The intake size for our larger vvt and milled head combos need the intake cut side. LS3 is a no go unless you go with a forged piston.