Help me pick a cam!
05-17-2007, 06:46 PM
#101
6600 rpm clutch dump of death Administrator
You keep jumping on Patrick about how he made a mistake. I've carefully read what he posted, and I fail to see where he made an error. In fact I would agree with him. SO, lets look at it empirically...
So, lets see... Here is a flowsheet on an Ls6 head
Intake Stock LS6
.050 -
.100 61.6
.150 93.6
.200 126.1
.250 155.9
.300 183.9
.350 205.9
.400 224.4
.450 239.1
.500 250.7
.525 -
.550 256
.575 -
.600 257.2
.625 -
.650 260.7
.700 263.6
Exhaust
.050 -
.100 56.7
.150 85.8
.200 107.8
.250 127.8
.300 142.5
.350 153.7
.400 162.5
.450 170.1
.500 175.7
.525 -
.550 180.0
.575 -
.600 183.2
.625 -
.650 185.2
.700 186.8
So, thats a stock 243 head with a 64 CC chamber. Now, your low lift numbers aren't pretty much right at stock. Mid lift is about +20, and your higher lift numbers ar right at +50.
Now, what was the opening on the plate your numbers were derived from?
Ok, so lets just look at your 67CC, and assume its correct. You are roughly at 10.4:1 with a .045 quench.
With a 64 CC chamber you are at 10.79 basically 10.8.
Compression is worth 3-4% of engine power per point. You are at ~40% of 1 point. So, you are looking at 1.2 - 1.6% loss of power (5.4 - 7.2 RWHP) just based on your lack of compression going from 64 to 67CC. Now, your flow number offset some of the CR loss. But, here is the issues. Most flow sheets I've seen are way off, and hopefully optimistic. Runner volumes are understated, Chamber volumes are understated, and flow numbers are usually fudged 10-20CFM. I'm assuming your numbers are just as you've posted them. But experiance has shown me that in reality your heads are probably closer to 71CC, and flow about 270-280 in reality. So, when you factor everything in consideration you are probably up +10 to +20 over a stock head. So, what are the best cam only Ls2's doing behind an auto?
Could you stick a big cam in the car and perhaps make a big number? Sure, with a 6 speed I'd say it is possible. But, based on the fact that it is an auto, then as Pat suggested, you have ahole to climb up out of. The real issue is that if you put a big stick in it with relatively low compression, you're going to knock the bottom out of the motor, and you're going to need a big stall to help overcome all that. To get a big stick in there to make a big number up top (mid 240's) The DCR is going to be about 7.3 :1
I'd say it is an ideal combo to go put a ton of dope on it to make up for the lack of power you are going to have.... You'll be satisfied then. Otherwise, up the CR...
Again, Pat's advice was spot on...
So, lets see... Here is a flowsheet on an Ls6 head
Intake Stock LS6
.050 -
.100 61.6
.150 93.6
.200 126.1
.250 155.9
.300 183.9
.350 205.9
.400 224.4
.450 239.1
.500 250.7
.525 -
.550 256
.575 -
.600 257.2
.625 -
.650 260.7
.700 263.6
Exhaust
.050 -
.100 56.7
.150 85.8
.200 107.8
.250 127.8
.300 142.5
.350 153.7
.400 162.5
.450 170.1
.500 175.7
.525 -
.550 180.0
.575 -
.600 183.2
.625 -
.650 185.2
.700 186.8
So, thats a stock 243 head with a 64 CC chamber. Now, your low lift numbers aren't pretty much right at stock. Mid lift is about +20, and your higher lift numbers ar right at +50.
Now, what was the opening on the plate your numbers were derived from?
Ok, so lets just look at your 67CC, and assume its correct. You are roughly at 10.4:1 with a .045 quench.
With a 64 CC chamber you are at 10.79 basically 10.8.
Compression is worth 3-4% of engine power per point. You are at ~40% of 1 point. So, you are looking at 1.2 - 1.6% loss of power (5.4 - 7.2 RWHP) just based on your lack of compression going from 64 to 67CC. Now, your flow number offset some of the CR loss. But, here is the issues. Most flow sheets I've seen are way off, and hopefully optimistic. Runner volumes are understated, Chamber volumes are understated, and flow numbers are usually fudged 10-20CFM. I'm assuming your numbers are just as you've posted them. But experiance has shown me that in reality your heads are probably closer to 71CC, and flow about 270-280 in reality. So, when you factor everything in consideration you are probably up +10 to +20 over a stock head. So, what are the best cam only Ls2's doing behind an auto?
Could you stick a big cam in the car and perhaps make a big number? Sure, with a 6 speed I'd say it is possible. But, based on the fact that it is an auto, then as Pat suggested, you have ahole to climb up out of. The real issue is that if you put a big stick in it with relatively low compression, you're going to knock the bottom out of the motor, and you're going to need a big stall to help overcome all that. To get a big stick in there to make a big number up top (mid 240's) The DCR is going to be about 7.3 :1
I'd say it is an ideal combo to go put a ton of dope on it to make up for the lack of power you are going to have.... You'll be satisfied then. Otherwise, up the CR...
Again, Pat's advice was spot on...
05-17-2007, 06:51 PM
#102
Originally Posted by QSPres
Sounds like Tiny is nervous. He's defending his history now....... 
I know Mike Dez well, as do I know Tbyrne, and Pat at OSP............
And I know what they'll say.
I know Mike Dez well, as do I know Tbyrne, and Pat at OSP............
And I know what they'll say.
Then why are you still asking for advice? You have talked to TEA and the other guys listed, and they all know their lsx stuff extremely well, so why even post up asking for a cam choice? Will they not spec one for you? Why not stop challenging people and post up a 500 rwhp graph of you stock 6.0 liter with the heads listed, 90/90 unported fast intake, and cam speced for you by one of the people above through a 12 bolt and stalled auto and prove everyone wrong? I hope you hit your mark of 500 rwhp though a stalled auto with a 12 bolt, I just dont see it happening...but again prove everyone wrong and im sure people will acknowledge the fact and applaud the build.
05-17-2007, 07:41 PM
#104
05-17-2007, 08:35 PM
#107
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Originally Posted by QSPres
Poor grammer at best..........
Is that the best you got? Its almost like playing with the retraded kid in class....
And anyone notice how many times the idiot has been interrupted? LOL
Is that the best you got? Its almost like playing with the retraded kid in class....
And anyone notice how many times the idiot has been interrupted? LOL
retarded
Good words to misspell when you are trying to prove how much smarter you are than everyone else.
05-17-2007, 08:40 PM
#108
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More untruths and assumptions leads to more wrong answers.......
Where to begin............
1. I get 10.6:1 compression when I do my calculations........ Just what TEA recommended...
2. The flow numbers I posted where done at an independant flow bench, not the head porters bench. They are correct and dead nuts on...
3. The head CC'd at 67. Just as I stated...
4. Your head flow data is unsupported, unverify-able, and incomplete....
So when I factor everything into consideration, your argument blows up.......
Again, I'm not concerned with making 500hp. I've already stated I don't care what the number says. I can just keep on going till I find a dyno that gives me the numbers I'm looking for anyway..... I want a car that can keep up with the newer cars. That's it and that's all..
Patrick made several mistakes about head flow and compression ratio, as did you, and that's a fact. He may know something about cams, but he dropped the ball here. And that's that.
Where to begin............
1. I get 10.6:1 compression when I do my calculations........ Just what TEA recommended...
2. The flow numbers I posted where done at an independant flow bench, not the head porters bench. They are correct and dead nuts on...
3. The head CC'd at 67. Just as I stated...
4. Your head flow data is unsupported, unverify-able, and incomplete....
So when I factor everything into consideration, your argument blows up.......
Again, I'm not concerned with making 500hp. I've already stated I don't care what the number says. I can just keep on going till I find a dyno that gives me the numbers I'm looking for anyway..... I want a car that can keep up with the newer cars. That's it and that's all..
Patrick made several mistakes about head flow and compression ratio, as did you, and that's a fact. He may know something about cams, but he dropped the ball here. And that's that.
Originally Posted by J-Rod
You keep jumping on Patrick about how he made a mistake. I've carefully read what he posted, and I fail to see where he made an error. In fact I would agree with him. SO, lets look at it empirically...
So, lets see... Here is a flowsheet on an Ls6 head
Intake Stock LS6
.050 -
.100 61.6
.150 93.6
.200 126.1
.250 155.9
.300 183.9
.350 205.9
.400 224.4
.450 239.1
.500 250.7
.525 -
.550 256
.575 -
.600 257.2
.625 -
.650 260.7
.700 263.6
Exhaust
.050 -
.100 56.7
.150 85.8
.200 107.8
.250 127.8
.300 142.5
.350 153.7
.400 162.5
.450 170.1
.500 175.7
.525 -
.550 180.0
.575 -
.600 183.2
.625 -
.650 185.2
.700 186.8
So, thats a stock 243 head with a 64 CC chamber. Now, your low lift numbers aren't pretty much right at stock. Mid lift is about +20, and your higher lift numbers ar right at +50.
Now, what was the opening on the plate your numbers were derived from?
Ok, so lets just look at your 67CC, and assume its correct. You are roughly at 10.4:1 with a .045 quench.
With a 64 CC chamber you are at 10.79 basically 10.8.
Compression is worth 3-4% of engine power per point. You are at ~40% of 1 point. So, you are looking at 1.2 - 1.6% loss of power (5.4 - 7.2 RWHP) just based on your lack of compression going from 64 to 67CC. Now, your flow number offset some of the CR loss. But, here is the issues. Most flow sheets I've seen are way off, and hopefully optimistic. Runner volumes are understated, Chamber volumes are understated, and flow numbers are usually fudged 10-20CFM. I'm assuming your numbers are just as you've posted them. But experiance has shown me that in reality your heads are probably closer to 71CC, and flow about 270-280 in reality. So, when you factor everything in consideration you are probably up +10 to +20 over a stock head. So, what are the best cam only Ls2's doing behind an auto?
Could you stick a big cam in the car and perhaps make a big number? Sure, with a 6 speed I'd say it is possible. But, based on the fact that it is an auto, then as Pat suggested, you have ahole to climb up out of. The real issue is that if you put a big stick in it with relatively low compression, you're going to knock the bottom out of the motor, and you're going to need a big stall to help overcome all that. To get a big stick in there to make a big number up top (mid 240's) The DCR is going to be about 7.3 :1
I'd say it is an ideal combo to go put a ton of dope on it to make up for the lack of power you are going to have.... You'll be satisfied then. Otherwise, up the CR...
Again, Pat's advice was spot on...
So, lets see... Here is a flowsheet on an Ls6 head
Intake Stock LS6
.050 -
.100 61.6
.150 93.6
.200 126.1
.250 155.9
.300 183.9
.350 205.9
.400 224.4
.450 239.1
.500 250.7
.525 -
.550 256
.575 -
.600 257.2
.625 -
.650 260.7
.700 263.6
Exhaust
.050 -
.100 56.7
.150 85.8
.200 107.8
.250 127.8
.300 142.5
.350 153.7
.400 162.5
.450 170.1
.500 175.7
.525 -
.550 180.0
.575 -
.600 183.2
.625 -
.650 185.2
.700 186.8
So, thats a stock 243 head with a 64 CC chamber. Now, your low lift numbers aren't pretty much right at stock. Mid lift is about +20, and your higher lift numbers ar right at +50.
Now, what was the opening on the plate your numbers were derived from?
Ok, so lets just look at your 67CC, and assume its correct. You are roughly at 10.4:1 with a .045 quench.
With a 64 CC chamber you are at 10.79 basically 10.8.
Compression is worth 3-4% of engine power per point. You are at ~40% of 1 point. So, you are looking at 1.2 - 1.6% loss of power (5.4 - 7.2 RWHP) just based on your lack of compression going from 64 to 67CC. Now, your flow number offset some of the CR loss. But, here is the issues. Most flow sheets I've seen are way off, and hopefully optimistic. Runner volumes are understated, Chamber volumes are understated, and flow numbers are usually fudged 10-20CFM. I'm assuming your numbers are just as you've posted them. But experiance has shown me that in reality your heads are probably closer to 71CC, and flow about 270-280 in reality. So, when you factor everything in consideration you are probably up +10 to +20 over a stock head. So, what are the best cam only Ls2's doing behind an auto?
Could you stick a big cam in the car and perhaps make a big number? Sure, with a 6 speed I'd say it is possible. But, based on the fact that it is an auto, then as Pat suggested, you have ahole to climb up out of. The real issue is that if you put a big stick in it with relatively low compression, you're going to knock the bottom out of the motor, and you're going to need a big stall to help overcome all that. To get a big stick in there to make a big number up top (mid 240's) The DCR is going to be about 7.3 :1
I'd say it is an ideal combo to go put a ton of dope on it to make up for the lack of power you are going to have.... You'll be satisfied then. Otherwise, up the CR...
Again, Pat's advice was spot on...
05-17-2007, 08:41 PM
#109
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Originally Posted by Louie83
grammar
retarded
Good words to misspell when you are trying to prove how much smarter you are than everyone else.
retarded
Good words to misspell when you are trying to prove how much smarter you are than everyone else.
And you'll notice how many picked up on it........ Again, retarded kids........
