Rhino

iTrader: (6)

I've seen people throwing around cam numbers and I'm extremely interested in choosing a new cam for my SS.
I recently got a set of stock LS1 heads that I'm going to have mildly ported and go for a new cam.

My main question is people talk about a "220" or a "230" cam and I'm unsure of what spec they're looking at. Exhaust or intake duration? duration@50? Possibly lift, in some strange unit that I'm unaware of?

I find it hard for someone to choose a cam on one number alone, Overlap, lope seperation and other factors would also play a key role in how "streetable" the cam would be.
Why do these numbers seem so ignored?

Am I completely off base on this?
It's been quite some time since I've had to choose a cam, and the first time in a street car.
Any help is greatly appreciated.

jmX

See the description here:
http://www.ls1howto.com/index.php?article=23

Rhino

iTrader: (6)

Thanks for the reply. I believe that that "220" or "230" that I see is actualy the degrees duration @ .050. Is this correct?

deviate42

iTrader: (2)

yep

Cal

iTrader: (1)

Cams used to be rated based on total duration, called "advertized duration." But that was an unreliable measure, so they are all rated at 50 thou (.050 inches) lift now. If you are more familiar with the old system, add 50 degrees to this to give you an idea of what the advertized duration would be. So that 220 cam is like a 270 of old but with a better idle due to fast ramps. It's too bad they don't advertize the overlap, but you can get it off the cam card that comes with the cam. With modern cams, duration and LSA doesn't give you the whole picture on overlap, because they play with the ramp rates a lot nowadays. This is made possible by the fact that all LS1s come with roller lifters. It all depends on what you want, but IMO the TR224 114 is sure a sweet cam based on the compromise of lift, duration, overlap, and ramp rates.

Tin Indian

Ditto what Cal said .....

The TR220 or the TR224 can be had with either a 112 LSA or a 114 LSA.

That TR224 on a 114 LSA would be perfect for an M6 car.

Maybe a TR220 on a 114 LSA with an Auto trans. The automatic cars have a harder time dealing with the larger duration cams than the M6 cars. They tend to have unstable/surging idle with big cams, but can be tuned to idle fairly smooth with LS1Edit programming, etc.

BTW, both these cams have 4 degrees of advance "ground-in" which aids in idle and gives better throttle response at low revs.

The 114 LSA will have a 110 degree Intake Centerline (IC)

The 112 LSA will have a 108 degree Intake Centerline (IC)

If installed dot-to-dot on the timing gears, this combo of LSA and IC will yield 4 degrees of advance on either cam.

Cal

iTrader: (1)

Very true. Be aware that idle tuning on LSx engines can be an interesting if not strange and bizarre experiance! You make changes to the PCM's tables, then the computer does what it wants, which changes from day to day based on it's "learning." Anyway, if you have an M6, you will be able to drive it without tuning if you have to, not true of an A4.

Visceral

iTrader: (1)

I want to just note, kind of trivia here and not very important...

When speaking of "Duration at .050" "...

.050" of lift is TAPPET LIFT. Tappet is another name for the lifter. Rather than .050" of lift seen at the valve, this is essentially lobe lift, and would be multiplied by the rocker ratio (1.70 in our case) to get valve lift with 0 lash. (.085 valve lift). Since you will rarely, if never, get a perfect 0 lash with 0 hydraulic bleed-down, this duration is measured at the cam lobe.

No biggie, but I dont want someone measuring and getting a number different than whats on the cam card.

chris

Rhino

iTrader: (6)

Thanks again for the replies. I learned exactly what I'm needing to know. I'm looking into the cams listed in this thread right now. The cam that I choose will still be fairly mild so that it's still very streetable. I figured idle tuning would be extremely interesting. This will be my first foray into street car cams as well as my first major project with LS1 edit. I'm sure there's bound to be a steep learning curve, but at least I'm ready for it.

I was a lot more familiar with the "old" cam specs. "The add 50 deg." makes a lot of sense.

A day never goes by that I don't learn a ton of good info from this board.

Does anybody have the stock cam #'s for an 02?

TXNC5

Just for some reference (I don't have the non-Z06 specs):

2002 Z06
204/218 .551/.541 117.5

2001 Z06
207/217 .525/.525 116


GM Performance Cams

LS1 Hot Cam
219/228 .525/.525 112

ASA Cam
226/236 .525/.525 110

and the big boy

Grand AM Cam
239/251 .570/.570 106 (me likey)

Rhino

iTrader: (6)

Here's what I've found so far for the 01-02 Camaro Cam specs...

198/208 .500/.500 LSA:115.5

deviate42

iTrader: (2)

the TR224 on a 114 is perfect for you. The cam idles great with very slight lope. You will be able to pass smog. the cam is easy to tune...etc

with all the boltons 385-400rwhp is a good goal for that cam

i had a TR224 on a 112 and i loved it.

Cal

iTrader: (1)

I second what Juice said! The amount of idle lope you get with this cam is largely a function of PCM tuning. BTW, the .500 lift cam is only used in vette's. Here's some more cam specs for ya:

TR224 Cam:
224/224 intake/exhaust degrees duration
.561 to .563 inches lift single pattern
112 or 114 LSA

FBODY CAMS

stock LS1 cam '98-00:
202/210 intake/exhaust degrees duration
.496/.496 inches lift
116 LSA

stock LS1 cam '01-02:
198/197 intake/exhaust degrees duration
.478/.478 inches lift
115 LSA

YBODY CAMS

Old LS6 cam:
207/217 intake/exhaust degrees duration
.525/.525 inches lift
116 LSA

New LS6 cam:
204/218 intake/exhaust degrees duration
.551/.547 inches lift
117 LSA