vmapper

iTrader: (8)

effective stroke changed, meaning either rod length, stroke and/or cam values changed, which they did, one is LS9 cam, the other is stock cam.

tommycompton

iTrader: (1)

lol ok, I see.
Sorry for how painfully slow this is, I've been looking at numbers and calculators all day and my brain is hurting.

The ls9 cam seems to be a safer bet on paper( to me anyway)

DMM

Static compression ratio of 10.01:1.
Effective stroke is 2.36 inches.
Your dynamic compression ratio is 6.71:1 .
Your dynamic cranking pressure is 126.25 PSI.
Your dynamic boost compression ratio, reflecting static c.r., cam timing, altitude, and boost of 6 PSI is 9.45 :1.
V/P (Volume to Pressure Index) is 90


Stock cam

Static compression ratio of 10.01:1.
Effective stroke is 2.59 inches.
Your dynamic compression ratio is 7.29:1 .
Your dynamic cranking pressure is 140.83 PSI.
Your dynamic boost compression ratio, reflecting static c.r., cam timing, altitude, and boost of 6 PSI is 10.27 :1.
V/P (Volume to Pressure Index) is 110

DMM

LMFAO! If it was easy, everyone would be doing it! It's all a part of learning. FWIW...I would use an LS7 cam instead of an LS9. Exact same cam with 120* LSA vice 122.5* LSA...it will help keep the powerband a little lower in the RPM range with a positive displacement blower.

tommycompton

iTrader: (1)

I had the ls9 cam as 122 lsa and 122.5 cl if thats the case its reversed
if i change it the results are a bit different. here are the ls7 and ls9

ls7 cam
Static compression ratio of 10.01:1.
Effective stroke is 2.39 inches.
Your dynamic compression ratio is 6.79:1 .
Your dynamic cranking pressure is 128.24 PSI.
Your dynamic boost compression ratio, reflecting static c.r., cam timing, altitude, and boost of 6 PSI is 9.56 :1.
V/P (Volume to Pressure Index) is 92


ls9
Static compression ratio of 10.1:1.
Effective stroke is 2.38 inches.
Your dynamic compression ratio is 6.82:1 .
Your dynamic cranking pressure is 128.99 PSI.
Your dynamic boost compression ratio, reflecting static c.r., cam timing, altitude, and boost of 6 PSI is 9.60 :1.
V/P (Volume to Pressure Index) is 93

Speaking of boost is would my DCR be considered safe? I'm assuming most ls6 guys with maggies are higher due to higher SCR to start with.

DMM

Why is your stroke different between the two? LSA should have no impact on the DCR between the LS7 and LS9, it's the relation between intake and exhaust events (overlap). Now you got me wondering, LOL!

Either way, that puts you right in the safe zone for DCR. Depending on your IAT's, you should be able to run decent timing advance with that setup...which is where you will really begin to feel the difference!


ls7 cam
Static compression ratio of 10.01:1.
Effective stroke is 2.39 inches.
Your dynamic compression ratio is 6.79:1


ls9
Static compression ratio of 10.1:1.
Effective stroke is 2.38 inches.
Your dynamic compression ratio is 6.82:1 .


All the numbers are starting to run together! haha..same thing happens to me!

tommycompton

iTrader: (1)

I used specs I found, there was a slight difference in 1* in ex and intake

DMM

That should not change your stroke though. Your compression is 10.01 for one and 10.1 for the other as well...numbers run together man, it's all good. What are the numbers with the amount of boost you currently have?

tommycompton

iTrader: (1)

Thanks for the patience and walking me through it. WTBS I think i would opt for the ls3 cam. Hopefully it's as cheap as the ls9 and fits, (haven't read up on the ls7 cam)
I don't have any numbers on my set up I never really ran it. ( i had the timing retarded so far back it had no power.)
I have meth to keep the Iats at bay, but want to keep my compression friendly for pump gas, and not be meth reliant for octane. I have two different pully sizes, so which ever one I can run safely I will.

DMM

LS3 is very very close to the LS6/LS2 cam. It wouldn't change much of anything. The LS7 and LS9 cams are identical, save for the +2* LSA on the LS9 and very minor intake lobe increase. Everything else is the same.

Here's something that may help...

tommycompton

iTrader: (1)

sorry ls3 was a mistype, I meant ls7. I can't even remember my phone number anymore.

DMM

And this...

PART NUMBER 12565308
PRODUCTION 2002 LS6 5.7L CAMSHAFT.
117.5 LDA 120 INTAKE CENTERLINE.
1.70 ROCKER RATIO
Lift:
@Cam @Valve
EXHAUST: 0.322 0.548
INTAKE: 0.324 0.551
Cam Timing@0.004-inch Tappet Lift:
Open Close Adv. Duration
EXHAUST: 69 BBDC 33 ATDC 282
INTAKE: 7 BTDC 80 ABDC 267
Cam Timing@0.050-inch Tappet Lift:
Open Close Duration
EXHAUST: 42 BBDC 4 BTDC 218
INTAKE: 19 ATDC 43 ABDC 204

LS7:
1.8 ROCKER RATIO
120 INTAKE CENTERLINE, 120.5 LOBE
DISPLACEMENT ANGLE
Lift:
@Cam @Valve
EXHAUST: 0.328 0.588
INTAKE: 0.331 0.593
Cam Timing@0.004-inch Tappet Lift:
Open Close Adv. Duration
EXHAUST: 80 BBDC 35 ATDC 295
INTAKE: 8 BTDC 89 ABDC 277
Cam Timing@0.050-inch Tappet Lift:
Open Close Duration
EXHAUST: 52 BBDC 2 BTDC 230
INTAKE: 18 ATDC 49 ABDC 211

LSA 12605220 CAM CARD INFORMATION:
119 INTAKE CENTERLINE, 119 LOBE DISPLACEMENT ANGLE
1.70 ROCKER RATIO
Lift:
@Cam @Valve
EXHAUST: 0.283 0.480 = 12.2 mm
INTAKE: 0.283 0.480 = 12.2 mm
Cam Timing@0.004-inch Tappet Lift:
Open Close Adv. Duration
EXHAUST: 79 BBDC 34 ATDC 293
INTAKE: 5 BTDC 86 ABDC 271
Cam Timing@0.050-inch Tappet Lift:
Open Close Duration
EXHAUST: 46 BBDC 10 BTDC 216
INTAKE: 21 ATDC 39 ABDC 198

LS9 12605227 CAM CARD INFORMATION:
122 INTAKE CENTERLINE, 122.5 LOBE
DISPLACEMENT ANGLE
1.70 ROCKER RATIO
Valve Lift:
@Cam @Valve
EXHAUST: 0.328 0.558 = 14.2 mm
INTAKE: 0.331 0.562 = 14.3 mm
Cam Timing@0.004-inch Tappet Lift:
Open Close Adv. Duration
EXHAUST: 84 BBDC 31 ATDC 295
INTAKE: 8 BTDC 89 ABDC 277
Cam Timing@0.050-inch Tappet Lift:
Open Close Duration
EXHAUST: 56 BBDC 6 BTDC 230
INTAKE: 18 ATDC 49 ABDC 211

PART NUMBER 12603844
LS3 CAM CARD DATA:
120 INTAKE CENTERLINE, 117.5 LOBE DISPLACEMENT ANGLE *LDA*
1.70 ROCKER RATIO
Valve Lift:
@Cam @Valve
Exhaust: 0.306 0.522 = 13.3 mm
Intake: 0.324 0.551 = 14.0 mm
Cam Timing@0.004-inch Tappet Lift:
Open Close Adv. Duration
Exhaust: 66 BBDC 29 ATDC 275
Intake: 7 BTDC 80 ABDC 267
Cam Timing@0.050-inch Tappet Lift:
Open Close Duration
Exhaust: 38 BBDC 7 BTDC 211
Intake: 19 ATDC 43 ABDC 204
PART NUMBER 12480033

LS SERIES HOT CAM
109 INTAKE CENTERLINE 112 LDA
1.71 INTAKE ROCKER RATIO
Lift:
@Cam @Valve
EXHAUST: 0.308 0.525
INTAKE : 0.308 0.525
Cam Timing@0.004-inch Tappet Lift:
Open Close Adv. Duration
EXHAUST: 75 BBDC 32 ATDC 287
INTAKE : 27 BTDC 71 ABDC 278
Cam Timing@0.050-inch Tappet Lift:
Open Close Duration
EXHAUST: 46 BBDC 0 ATDC 226
INTAKE : 1 ATDC 39 ABDC 218

PART NUMBER 12612273
2007 L92 6.2L CAM AT NOMINAL TIMING:
115.5 LDA 116 INTAKE CENTERLINE ‘NOMINAL’
(99 AT PHASER PARK)
1.70 ROCKER RATIO
Lift:
@Cam @Valve
EXHAUST: 0.294 0.500
INTAKE: 0.294 0.500
Cam Timing@0.004-inch Tappet Lift:
Open Close Adv. Duration
EXHAUST: 69 BBDC 35 ATDC 284
INTAKE: 8 BTDC 90 ABDC 278
Cam Timing@0.050-inch Tappet Lift:
Open Close Duration
EXHAUST: 38 BBDC 9 BTDC 209
INTAKE: 18 ATDC 36 ABDC 198

PART NUMBER 12561721
116 LDA 115 INTAKE CENTERLINE.
PRODUCTION 2001 6.0L TRUCK AND 5.7L
LS1 CAR CAMSHAFT.
1.7 ROCKER RATIO
Lift:
@Cam @Valve
EXHAUST: 0.281 0.475
INTAKE: 0.274 0.463
Cam Timing@0.004-inch Tappet Lift:
Open Close Adv. Duration
EXHAUST: 71 BBDC 33 ATDC 284
INTAKE: 11 BTDC 87 ABDC 278
Cam Timing@0.050-inch Tappet Lift:
Open Close Duration
EXHAUST: 39 BBDC 12 BTDC 207
INTAKE: 17 ATDC 33 ABDC 196

PART NUMBERS 12560950,12593206
2001 LS6 AND LS2 CAM DATA
116 LDA AND 118 INTAKE TIMING.
1.70 ROCKER RATIO
Lift:
@Cam @Valve
EXHAUST: 0.308 0.524
INTAKE: 0.308 0.524
Cam Timing@0.004-inch Tappet Lift:
Open Close Adv. Duration
EXHAUST: 65 BBDC 30 ATDC 275
INTAKE: 9 BTDC 81 ABDC 270
Cam Timing@0.050-inch Tappet Lift:
Open Close Duration
EXHAUST: 37 BBDC 6 BTDC 211
INTAKE: 18 ATDC 42 ABDC 204

tommycompton

iTrader: (1)

Thanks for the list, read that from your link.

The ls7 is a 1.8 rocker cam.
I already have a set of 1.7 rollers.

DMM

No worries...cam lobe lift is almost identical to the LS9, the 1.8 rockers is what gives the LS7 increased valve lift over the LS9 cam.

Divide the LS7 cam lift by 1.8 and the LS9 lift by 1.7 and you will get the actual lobe lift for each.

Don't get me wrong, an LS9 would work well as has been stated by others here in the thread and is proven. I think the LS7 might work a tad better b/c of the tighter LSA...and you might be able to get it a little cheaper since the Z06 guys have them laying around as takeouts.

I think Fuzzy's cam (Torquer V3) would be ideal for both of us honestly, but since you're not looking for power and would rather retain drivability you probably should stick with the GM cam. Cheap, easy, proven...done.


Edit: I re-ran some of your numbers (based off your 10.01:1 SCR number)...it looks as if you could safely run 8 lbs of boost and still have a DCR of 9.68:1 (9 PSI would put you at 10.11:1), which is very street friendly. Here's the thing, since you have more efficient heads, you're going to have less boost than you do now...since boost is a measurement back pressure (resistance to flow). If you have a a 10 lb pulley now, it may very well end up being 8 lbs after you install the AFR heads. After that, the only thing holding you back is your IAT's, which should improve as well with decreased boost pressures. Maybe the "Killer Chiller" could help with your IAT's as well.

vmapper

iTrader: (8)

For knowledge discussion, what have you found or read to be a 91/93 octane pump friendly Boost DCR ratio?
14:1?
15:1?
20:1?

Also, we can see cylinder pressure is not an issue, and more than likely, requires additional timing in areas with low boost to make up for the lower cyl pressure. (sluggish feel)

Ive read and follow the 175-180psi to be pump threshold. this would indicate a ~17.5:1 DCR (with boost).
Is this a guideline you follow?
Thoughts?

tommycompton

iTrader: (1)

Right now I'm at a guesstimation for PSI. I figure one of my pulleys was ~8psi, so used 6 as a conservative figure with a the better flowing heads and drop in compression. Killer chiller was an option I considered as well, I may still look into doing it. Very cool idea indeed. I'll see how my Iats do with meth and decide from there. This thread has been very helpfull thanks to you and Vmapper.

tommycompton

iTrader: (1)

Ls7 cam is turning out not to be an easy find

NOEXCUSES

I have plenty of LS7 cams and you can have one (just pay my time to box it up and shipping.

John Page
www.21stcenturymusclecars.com

tommycompton

iTrader: (1)

Thanks for the offer.

I am still torn between the ls7 and ls9 cam
here are my numbers,(no errors this time)

Static compression ratio of 10.001:1.
Effective stroke is 2.44 inches.
Your dynamic compression ratio is 6.91:1 .
Your dynamic cranking pressure is 131.25 PSI.
Your dynamic boost compression ratio, reflecting static c.r., cam timing, altitude, and boost of 6 PSI is 9.73 :1.
V/P (Volume to Pressure Index) is 97



Static compression ratio of 10.001:1.
Effective stroke is 2.38 inches.
Your dynamic compression ratio is 6.76:1 .
Your dynamic cranking pressure is 127.49 PSI.
Your dynamic boost compression ratio, reflecting static c.r., cam timing, altitude, and boost of 6 PSI is 9.52 :1.
V/P (Volume to Pressure Index) is 92



I'm still wondering if I should go with the LS9 cam with less DCR with more potential to raise boost?
or are the numbers so close it doesn't matter?

I will look for more insight and let you know by the end of the weekend.
BTW what is your time worth?
is it a low milage take out?
You can PM me if you like.

punishmentcycle

iTrader: (6)

they are so close i doubt youll notice much of a difference... but as an fyi i bought my ls9 from lingenfelter for 129. they were the cheapest i could find. and tne ls9 springs were i think 40. try them