Cams with -1 overlap?
#21
267 278 advertised duration 217/228 112/108 those are the only specs I have on it. Does the bigger split make any sound?
I have heard some small truck cams that sound good too. Allot of them were in 4.8-5.3 engines though.
I have heard some small truck cams that sound good too. Allot of them were in 4.8-5.3 engines though.
#22
9 Second Club
iTrader: (7)
48.5* of overlap at .004 numbers........whcih is about right for a mild performance cam
heres what about 100* of overlap sounds like....keep in mind i dont start making power till around 6400.....
http://www.youtube.com/watch?v=uN2d6rXJpBM
#23
Ok so using advertised duration I get 48.5
According to othe GM high tech cam test that would put this cam in medium street manners, detectable that it has a cam, some lope.
http://www.gmhightechperformance.com.../photo_15.html
According to othe GM high tech cam test that would put this cam in medium street manners, detectable that it has a cam, some lope.
http://www.gmhightechperformance.com.../photo_15.html
#24
9 Second Club
iTrader: (7)
Ok so using advertised duration I get 48.5
According to othe GM high tech cam test that would put this cam in medium street manners, detectable that it has a cam, some lope.
http://www.gmhightechperformance.com.../photo_15.html
According to othe GM high tech cam test that would put this cam in medium street manners, detectable that it has a cam, some lope.
http://www.gmhightechperformance.com.../photo_15.html
i street drive a 226/234 .600/.600 112LSA daily in my LS2 GTO and tuned perfect it runs great idles at 875 and can cruise around at 1100 no problem......90% of it is in the tune unless you get really crazy with the cam specs
#25
Ok thats good, I just wanted to make sure I can hear some cam! Just wanted to make sure it would wake this thing up in the sound department to. Thanks for all the help guys
#27
TECH Enthusiast
iTrader: (36)
The cam in my TA has 0 deg overlap,
I thought it would idle like stock, but you can still hear a slight lope @ 700 RPM
Though the snappy low end torque sure is fun on the street.
The previous cam had 6 deg overlap. Below 3500 RRM, it did not have near the torque it does now. However, above 3500, it would feel like boost kicking in.
I have another cam with 17 deg overlap I was going to use, but in wanting better drive ability, I went the other way.
With the larger cam, I might gain HP, but I'd loose some of low end torque.
I thought it would idle like stock, but you can still hear a slight lope @ 700 RPM
Though the snappy low end torque sure is fun on the street.
The previous cam had 6 deg overlap. Below 3500 RRM, it did not have near the torque it does now. However, above 3500, it would feel like boost kicking in.
I have another cam with 17 deg overlap I was going to use, but in wanting better drive ability, I went the other way.
With the larger cam, I might gain HP, but I'd loose some of low end torque.
#28
Thanks for the replies guys, this sounds like I should be happy then! That top end boost feel is not what I want either, I want as much power as possible from about 2000-6000. I feel it was actually make the car much faster then having a big cam and waiting for that top end pull. We will see huh, having 1 chamber flowmasters should help too.
#30
12 Second Club
iTrader: (20)
Thanks for the replies guys, this sounds like I should be happy then! That top end boost feel is not what I want either, I want as much power as possible from about 2000-6000. I feel it was actually make the car much faster then having a big cam and waiting for that top end pull. We will see huh, having 1 chamber flowmasters should help too.
#31
Staging Lane
iTrader: (1)
Cam overlap is only one of many elements in making a great performing engine. A cam with lots of overlap is helpful with heads that don't flow well. Lots of overlap help move air thru the cylinder because of poor flowing ports of these older heads.
If you have great flowing heads with lots of port velocity, it accomplishes the same goal of a cam with lots of overlap. The LS heads are a different animal and flow much better so a lot less overlap is needed to make power.
My LS2 with CNC heads, small Lingenfelter GT-11 cam makes 458 rwhp, idles smooth at 675 rpm, and makes great torque from 1000 to 6500 rpm. This cam has -12 overlap. Big overlap is not needed to make good power on good flowing and high velocity heads.
If you have great flowing heads with lots of port velocity, it accomplishes the same goal of a cam with lots of overlap. The LS heads are a different animal and flow much better so a lot less overlap is needed to make power.
My LS2 with CNC heads, small Lingenfelter GT-11 cam makes 458 rwhp, idles smooth at 675 rpm, and makes great torque from 1000 to 6500 rpm. This cam has -12 overlap. Big overlap is not needed to make good power on good flowing and high velocity heads.
#32
Whats your guys take on the ASA cam, would that cam work good in a LS3? Do you guys think it would be a better choice? Found another intresting one from lunati, ADV 287/298 222/230 114
Last edited by sweetC5; 01-27-2012 at 08:49 AM.
#35
TECH Enthusiast
iTrader: (36)
Yes, that 222/230 would work, but probably not optimal.
I agree, 10 > 12 degrees is the split I've seen on cams for ls3 and ls7 heads
Just seen this cam on Vengance Racing website for L92 / LS3 heads.
https://www.vengeancerd.com/ecart/pr....617-115%252b4
- 1.5 overlap but you should still hear it due to the duration
I agree, 10 > 12 degrees is the split I've seen on cams for ls3 and ls7 heads
Just seen this cam on Vengance Racing website for L92 / LS3 heads.
https://www.vengeancerd.com/ecart/pr....617-115%252b4
- 1.5 overlap but you should still hear it due to the duration
Last edited by davidws6; 01-27-2012 at 05:42 PM. Reason: .
#37
Launching!
iTrader: (1)
217/228 112/108
IVO: 0.5 ° BTDC
IVC: 36.5 ° ABDC
EVO: 50.0 ° ATDC
EVC: -2.0 ° BBDC
Overlap: -1.5 °
#38
LS1 Tech Administrator
iTrader: (14)
Yes, that 222/230 would work, but probably not optimal.
I agree, 10 > 12 degrees is the split I've seen on cams for ls3 and ls7 heads
Just seen this cam on Vengance Racing website for L92 / LS3 heads.
https://www.vengeancerd.com/ecart/pr....617-115%252b4
- 1.5 overlap but you should still hear it due to the duration
I agree, 10 > 12 degrees is the split I've seen on cams for ls3 and ls7 heads
Just seen this cam on Vengance Racing website for L92 / LS3 heads.
https://www.vengeancerd.com/ecart/pr....617-115%252b4
- 1.5 overlap but you should still hear it due to the duration
Yes, the rectangular port heads flow very well on the intake side. It's been well documented that they require 4-6 degrees less duration than a cathedral port LS2 head to make the same power or more. So if a 228R would be a good daily driver cam for a 6.0L, than a 224/228 or a 222/228 cam would be appropriately sized for a 6.0L with L92/LS3 heads. Those who are advocating huge exhaust duration or large 10-12 degree splits are not looking hard enough at what's going on in the exhaust cycle of the combustion process.
Stock L92 head flow numbers from Richard at West Coast Cylinder heads:
4.030” test bore
Lift ___.100 _.150_.200_.250_.300 _.350 _.400 _.450 _.500 _.550 _.600 _.650_.700_.750
#1 Int. 74.9 109.4 154.4 193.5 225.3 252.8 274.6 292.7 308.8 321.0 328.7 326.6 310.0 316.6
#1 Exh. 63.6 97.9 126.1 148.7 162.3 178.6 189.6 197.6 205.5 210.7 214.6 217.8 221.2 223.5
The intake was tested with a radius plate and the exhaust was tested with a 2 ½” stub pipe.
4.155” test bore
Lift ___.100 _.150_.200_.250_.300 _.350 _.400 _.450 _.500 _.550 _.600 _.650_.700_.750
#1 Int. 73.8 108.7 153.2 192.6 225.2 253.6 277.0 296.7 313.0 326.0 335.8 326.9 327.3 317.1
#1 Exh.61.1 97.9 125.7 148.1 162.0 179.5 191.8 200.1 205.9 213.3 218.4 220.9 221.9 223.2
The intake was tested with a radius plate and the exhaust was tested with a 2 ½” stub pipe.
Casting Number 243
Head: 2001 LS6 5.7 Liter Passenger Car
Material: Aluminimum
Part Number:
12564243
Combustion Chamber Volume: 64.45cc
Compression Ratio: 10.5:1
Intake Port Volume: 210cc
Exhaust Port Volume: 75cc
Intake Valve Diameter: 2.00 inches
Exhaust Valve Diameter: 1.55 inches
Stock 243 (LS6/LS2) Head Flow Numbers
Chamber 64.45 cc-------0.100---0.200--0.300--0.400---0.500---0.550---0.600
Intake 210 cc------------62------126----184----224-----251----256----257
Exhaust 75 cc------------57------108----143----163-----176----180----183
LS2 head flow on Bo White's flow bench:
.200 137/115
.300 194/150
.400 237/175
.500 262/186
.600 251/197
3.900 bore, 1 7/8 pipe
The point is, the L92/LS3 heads have a larger 1.59 exhaust valve and larger port and flow more than LS6/LS2 exhaust ports with stock 1.55 exhaust valves in these flow sheets. In summary, it does not make sense to give a 6.0/6.2L more exhaust duration with a L92/LS3 head than you would with an LS6/LS2 head. I hope these flow sheets help support this. It's the intake that can take LESS duration. Let's stop repeating that LS3/L92 heads require big splits (like 10 degrees or more) like it's gospel. That is not necessarily the facts. Hopefully, the illustration above shed some additional light on what it takes to correctly cam a rectangular port cylinder head.
__________________
2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads. 506rwhp/442rwtq. 11.413 @ 121.29mph 1/4 mile, 168.7mph TX Mile
2000 Pewter Ram Air Trans Am M6 heads/cam 508 rwhp/445 rwtq SAE, 183.092 TX Mile
2022 Cadillac Escalade 6.2L A10 S&B CAI, Corsa catback.
2023 Corvette 3LT Z51 soon to be modified.
Custom LSX tuning in person or via email press here.
2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads. 506rwhp/442rwtq. 11.413 @ 121.29mph 1/4 mile, 168.7mph TX Mile
2000 Pewter Ram Air Trans Am M6 heads/cam 508 rwhp/445 rwtq SAE, 183.092 TX Mile
2022 Cadillac Escalade 6.2L A10 S&B CAI, Corsa catback.
2023 Corvette 3LT Z51 soon to be modified.
Custom LSX tuning in person or via email press here.
#39
Thanks for your input, so would you say that 222/228 would be a good choice for my ls3 then? That actually was the cam I was going to run from the get go, but all this talk in a big split made me change my mind. I can get a good deal on a voodoo 222/228 cam!
#40
12 Second Club
iTrader: (20)
Sounds good I'll just pm Comp cams and tell them they are building the wrong cams and are telling us consumers bad advise and bad products.
I'm no expert but I have talked to Comp Ls reps along with other vendors like LPE (who's heads I bought for my build and recommended me a cam very similar to the one comp did) and all have said what has worked for them. Is it a coincidence? I don't think so!
I'm no expert but I have talked to Comp Ls reps along with other vendors like LPE (who's heads I bought for my build and recommended me a cam very similar to the one comp did) and all have said what has worked for them. Is it a coincidence? I don't think so!