404ci ls2 can selection nee help?
02-23-2019, 08:42 PM
#1
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404ci ls2 can selection nee help? Hi I have a 404ci ls2 with advanced inductions cnc ported 823 heads which are milled to 64cc. Anyways I am having the worst time trying to pick a cam, I currently have a tsp 228/232 .600/.600 112 lsa cam that I think is to small, but it came with the engine when I bought it. Any recommendations on what to get? I want to be able to daily drive the car without chugging in 5th or 6th gear but i do want to have a noticeable exhaust note.
Thanks
Thanks
02-24-2019, 12:18 AM
#2
Best IVC is 50 and EVO is around 64 for power with a 4" stroke and LS3 heads. If you want it to drive nice, I'd bias toward the exhaust 2-3 degrees. And put the IVO at 6 and the EVC at 8 degrees for 14 degrees overlap. Which is a healthy amount of overlap, but won't drive stupid or horrible in a 402.
And what cam do you get with that?
236/252 115+3.
I'd look at running a 1.85:1 YT Roller Rocker with PAC 1207X springs and go with a TSP or Cam Motion lobe with a 365 lobe lift intake and 355 lobe lift exhaust. That would end up as a 675 intake lift and 656 exhaust at the valve.
Why would I do that? LS3 heads flow better at 650 and 700 lift than the cathedral stuff. They need more lift. Going to a setup like that keeps you from having to go to a crazy aggressive lobe. If you try to get to 675 lift on a 1.7:! rocker, it'll be a bit too aggressive. And I wouldn't do that with a stock rocker. The roller stuff, especially when moving up in ratio, is good for at least 20 HP if you can control it.
And what cam do you get with that?
236/252 115+3.
I'd look at running a 1.85:1 YT Roller Rocker with PAC 1207X springs and go with a TSP or Cam Motion lobe with a 365 lobe lift intake and 355 lobe lift exhaust. That would end up as a 675 intake lift and 656 exhaust at the valve.
Why would I do that? LS3 heads flow better at 650 and 700 lift than the cathedral stuff. They need more lift. Going to a setup like that keeps you from having to go to a crazy aggressive lobe. If you try to get to 675 lift on a 1.7:! rocker, it'll be a bit too aggressive. And I wouldn't do that with a stock rocker. The roller stuff, especially when moving up in ratio, is good for at least 20 HP if you can control it.
02-24-2019, 03:33 PM
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Cam Motion has 2 Shelf stroker Cams for Rectangle Ports that would be MUCH BETTER
for a daily driver than the above suggested cam IMO.
1. Stealthy Stroker 230*/242* 117*+5*
2. Torquey Stroker 232*/242* 114*+4*
A Ported stock Intake or long runner FAST will Peak before 6500 RPM in a Stroker
anyway, let the Stroke and excellent Ported Heads do the work, and in a DD especiallly
er on the smaller side. Regarding lift 1207X Springs & .670"+ lift will need more
maintenance Vs < .630" with bushing upgraded stock Rockers and milder springs.
Your chop & lope will come from a 650 RPM Idle with a good tune.
Good Luck
Daily Driving means different things to different people and driving environments.
For me DD includes 3X/week the hills and stop and go of SF with a Manual C6 by a 50+ yr old.
A Teen, early 20s driving the flat plains of Texas the other end of the spectrum.
for a daily driver than the above suggested cam IMO.
1. Stealthy Stroker 230*/242* 117*+5*
2. Torquey Stroker 232*/242* 114*+4*
A Ported stock Intake or long runner FAST will Peak before 6500 RPM in a Stroker
anyway, let the Stroke and excellent Ported Heads do the work, and in a DD especiallly
er on the smaller side. Regarding lift 1207X Springs & .670"+ lift will need more
maintenance Vs < .630" with bushing upgraded stock Rockers and milder springs.
Your chop & lope will come from a 650 RPM Idle with a good tune.
Good Luck
Daily Driving means different things to different people and driving environments.
For me DD includes 3X/week the hills and stop and go of SF with a Manual C6 by a 50+ yr old.
A Teen, early 20s driving the flat plains of Texas the other end of the spectrum.
02-24-2019, 04:05 PM
#4
The lobes would be what determines the ultimate longevity of a spring. And most of the lobes in the .600 lift range with something like BTR Platinums and stock rockers aren't really any different that what I'd recommend. I'd just step up to a slightly better spring to handle the YTs... and go for more lift. People wonder why LS3s don't perform--it's because of advice like that.
We are still talking about 25k miles on those springs before you might consider replacing them. Probably closer to 30-35k.
And 2 degrees of overlap in a 402 is going to drive like stock. And sound stock. And barely be an upgrade over where he is now. Actually, it might make less power as it has less overlap. So, let's waste his time with the cam swap.
The other cam has 9 degrees of overlap vs the current 6. The difference between 9 and 14 on a 402 is really nothing and 6 and 9 is actually nothing. The valve events are better allowing it to make power higher in the RPM range. And at some point, overlap starts to hurt an LS3 head, but that limit is not 9 degrees on a 402.
I am sensitive to overlap. I hate the way an overcammed car drives. I've been through 4 in just this engine. But the difference between them isn't really that much. The difference between 4 and 16 degrees of overlap isn't much if you can tune the car.
You'd pick up 40HP with my cam/rocker combo, and it'd drive fine.
With the first cam, you'd pick up less than 10 (and would probably lose torque and power overall) and it'd drive exactly the same with less exhaust note. The second cam might pick up 20 and drive pretty similar to what you have now except power would be shifted up the RPM range. It would also drive similar to my cam spec.
As far as power goes...that's peak. My spec would pick up more under the curve with the added rocker ratio. Remember, the stock rocker is 1.5 off the seat and grows to 1.7... these would be 1.85:1 off the seat. So, you'd end up with better vacuum and low speed drivability, with all else being equal.
We are still talking about 25k miles on those springs before you might consider replacing them. Probably closer to 30-35k.
And 2 degrees of overlap in a 402 is going to drive like stock. And sound stock. And barely be an upgrade over where he is now. Actually, it might make less power as it has less overlap. So, let's waste his time with the cam swap.
The other cam has 9 degrees of overlap vs the current 6. The difference between 9 and 14 on a 402 is really nothing and 6 and 9 is actually nothing. The valve events are better allowing it to make power higher in the RPM range. And at some point, overlap starts to hurt an LS3 head, but that limit is not 9 degrees on a 402.
I am sensitive to overlap. I hate the way an overcammed car drives. I've been through 4 in just this engine. But the difference between them isn't really that much. The difference between 4 and 16 degrees of overlap isn't much if you can tune the car.
You'd pick up 40HP with my cam/rocker combo, and it'd drive fine.
With the first cam, you'd pick up less than 10 (and would probably lose torque and power overall) and it'd drive exactly the same with less exhaust note. The second cam might pick up 20 and drive pretty similar to what you have now except power would be shifted up the RPM range. It would also drive similar to my cam spec.
As far as power goes...that's peak. My spec would pick up more under the curve with the added rocker ratio. Remember, the stock rocker is 1.5 off the seat and grows to 1.7... these would be 1.85:1 off the seat. So, you'd end up with better vacuum and low speed drivability, with all else being equal.
02-24-2019, 05:14 PM
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"The the difference between 4 and 16 degrees of overlap isn't that much if you can tune the car"
Agree to Disagree!
OP talk with Cam Motion (Steve or Kip) and ask their opinion, be honest & accurate about
your goals and DD parameters and they will steer you right.
Agree to Disagree!
OP talk with Cam Motion (Steve or Kip) and ask their opinion, be honest & accurate about
your goals and DD parameters and they will steer you right.
02-24-2019, 05:32 PM
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Thanks for the replies everyone, I forgot to mention I have tsp dual springs and a fast 102 intake. I will talk to cam motion and do some thinking about all the suggestions you guys have listed.
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05-12-2019, 08:43 AM
#10
Best IVC is 50 and EVO is around 64 for power with a 4" stroke and LS3 heads. If you want it to drive nice, I'd bias toward the exhaust 2-3 degrees. And put the IVO at 6 and the EVC at 8 degrees for 14 degrees overlap. Which is a healthy amount of overlap, but won't drive stupid or horrible in a 402.
And what cam do you get with that?
236/252 115+3.
I'd look at running a 1.85:1 YT Roller Rocker with PAC 1207X springs and go with a TSP or Cam Motion lobe with a 365 lobe lift intake and 355 lobe lift exhaust. That would end up as a 675 intake lift and 656 exhaust at the valve.
Why would I do that? LS3 heads flow better at 650 and 700 lift than the cathedral stuff. They need more lift. Going to a setup like that keeps you from having to go to a crazy aggressive lobe. If you try to get to 675 lift on a 1.7:! rocker, it'll be a bit too aggressive. And I wouldn't do that with a stock rocker. The roller stuff, especially when moving up in ratio, is good for at least 20 HP if you can control it.
And what cam do you get with that?
236/252 115+3.
I'd look at running a 1.85:1 YT Roller Rocker with PAC 1207X springs and go with a TSP or Cam Motion lobe with a 365 lobe lift intake and 355 lobe lift exhaust. That would end up as a 675 intake lift and 656 exhaust at the valve.
Why would I do that? LS3 heads flow better at 650 and 700 lift than the cathedral stuff. They need more lift. Going to a setup like that keeps you from having to go to a crazy aggressive lobe. If you try to get to 675 lift on a 1.7:! rocker, it'll be a bit too aggressive. And I wouldn't do that with a stock rocker. The roller stuff, especially when moving up in ratio, is good for at least 20 HP if you can control it.
242/257 .660 .655 113 LSA +3 IVC 51 EVO 65 with a 1:81 rocker ratio (12:8.1 compression)
05-12-2019, 09:14 AM
#11
TECH Veteran
Its really hard to spec a camshaft without knowing your rear gear ratio. The OP mentioned "chugging"... i can tell you guys from my personal experience the more rear gear you have the less "bucking/chucking" you'll have down low. More gear means you can run more camshaft and get away with it. By the car being a 6 speed... dont be scared of gears.