Cam selection for LSX 454
06-03-2007, 04:34 AM
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Cam selection for LSX 454 Wanted to get some peoples thoughts on cam selection for an LSX 454. The vehicle is heavy, around 4200 lb with me in it.
It will most likely be running ported LS7 heads and LS7 manifold with 90mm TB.
From what I've read, the LS7 heads have a weak exhaust side so a split cam with more exhaust is desirable. How much split is required?
What I'm looking for:
I'm thinking something like 232/242 with around .600 lift, 114 lsa. Yes, I know that sounds like a baby cam, and maybe it is for these cubes? What would be a similar cam for these cubes as the 222/224 is for a 346 cuber? Appreciate eveyone's suggestions.
It will most likely be running ported LS7 heads and LS7 manifold with 90mm TB.
From what I've read, the LS7 heads have a weak exhaust side so a split cam with more exhaust is desirable. How much split is required?
What I'm looking for:
- Don't want to sacrifice low down torque (if possible), whilst still having a good top end. Although with a 454 I guess you can sacrifice a bit as the cubes give so much torque anyway?
- Want it to drive nice - not a pig around town or in traffic
- Car is used to ferry the family around on trips etc, not for milk at the shops
- Will only rev to around 6500 odd, I'm not a drag racer, so peak power at or before 6500 rpm.
- Similar in manners etc as the 222/224 is for a 346 cuber - nice in other words but not all out.
- So what is the best "all-round" cam without worrying about it being a strip warrior?
I'm thinking something like 232/242 with around .600 lift, 114 lsa. Yes, I know that sounds like a baby cam, and maybe it is for these cubes? What would be a similar cam for these cubes as the 222/224 is for a 346 cuber? Appreciate eveyone's suggestions.
06-03-2007, 08:31 AM
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I read about a formula for this. If you know that in a 346 the 222/224 is exactly what you want then you work out the difference in cid between the 346 and 454 as a fraction.
So 454/346= 1.3121 take the sq rt of that, which is (nicely enough) 1.1454
Then multiply the durations by that number, so 222/224 is 254 degree's intake.
However I imagine that only applies where valve ratios and head design is similar.
However if its only vaguely right, then you can probably go bigger than your 232.
So 454/346= 1.3121 take the sq rt of that, which is (nicely enough) 1.1454
Then multiply the durations by that number, so 222/224 is 254 degree's intake.
However I imagine that only applies where valve ratios and head design is similar.
However if its only vaguely right, then you can probably go bigger than your 232.
06-03-2007, 12:14 PM
#3
I'm thinking of building the same setup, (454) so I've been doing some math myself. My application is light weight, (under 3200 with me in it so I don't think I need to carry around a bunch of torque) street/strip but with the high percentage being street. I read one post that said to add 13 degrees duration to what ever you liked in a 346 for use in a 427. So I beat that figure around a bit and came up with around 246/252 for a duration figure, (454), (seems tiny to me). I just used "ringram" numbers and came up with 260/266, (more like it). I'm using a known reference cam for a 402 that has outstanding performance and worked the math down to 346 and up to 454. Of course all of this bench math would require you know head flow numbers as well with final lift and duration numbers referenced to them. 
D.J.
D.J.
Last edited by OneQuickCoupe; 06-03-2007 at 01:35 PM.
06-03-2007, 05:05 PM
#4
Your 232/242 114 LSA is probably not far off.
For reference, the 454 LSx build that was done for Reggie Jackson's '69 Camaro, using GM LS7 heads, used a 236/246 110 LSA and made 640 HP, 611 ft-lb on an engine dyno. That engine used a carb-style intake - the barrel-style plastic intakes seem to like somewhat later intake valve open and close, which your greater LSA would give you assuming you use a +2 to +4 advance. Your cam works out to 8 degrees overlap at .050 - which will be fairly tame on a 454. For reference, here is an idle clip of a Katech torquer cam on a 427, with 12 degrees overlap at .050 (scroll down to the middle of the page):
http://www.corsaperf.com/c6_z06.htm
I'd guess your power peak would end up around 6100 - 6200 with LS7 intake, which is perfect for 6500 RPM redline.
If I were to change anything about that cam, I might open the exhaust valve a little earlier with a slightly bigger exhaust lobe and wider LSA - say, 232/244 115 LSA, or 232/246 116 LSA, either of them on about a 110 ICL.
I'd use Comp XER lobes and get a little more lift than .600, although you don't need the lift on the exhaust side as much and could go with a less aggressive lobe there. X-ER lobes are harder on springs, but if you're not spinning it to 6500 every stop light, this is probably not much of an issue.
For reference, the 454 LSx build that was done for Reggie Jackson's '69 Camaro, using GM LS7 heads, used a 236/246 110 LSA and made 640 HP, 611 ft-lb on an engine dyno. That engine used a carb-style intake - the barrel-style plastic intakes seem to like somewhat later intake valve open and close, which your greater LSA would give you assuming you use a +2 to +4 advance. Your cam works out to 8 degrees overlap at .050 - which will be fairly tame on a 454. For reference, here is an idle clip of a Katech torquer cam on a 427, with 12 degrees overlap at .050 (scroll down to the middle of the page):
http://www.corsaperf.com/c6_z06.htm
I'd guess your power peak would end up around 6100 - 6200 with LS7 intake, which is perfect for 6500 RPM redline.
If I were to change anything about that cam, I might open the exhaust valve a little earlier with a slightly bigger exhaust lobe and wider LSA - say, 232/244 115 LSA, or 232/246 116 LSA, either of them on about a 110 ICL.
I'd use Comp XER lobes and get a little more lift than .600, although you don't need the lift on the exhaust side as much and could go with a less aggressive lobe there. X-ER lobes are harder on springs, but if you're not spinning it to 6500 every stop light, this is probably not much of an issue.
06-11-2007, 06:10 PM
#5
Originally Posted by 71CamaroLS1
Your 232/242 114 LSA is probably not far off.
For reference, the 454 LSx build that was done for Reggie Jackson's '69 Camaro, using GM LS7 heads, used a 236/246 110 LSA and made 640 HP, 611 ft-lb on an engine dyno. That engine used a carb-style intake - the barrel-style plastic intakes seem to like somewhat later intake valve open and close, which your greater LSA would give you assuming you use a +2 to +4 advance. Your cam works out to 8 degrees overlap at .050 - which will be fairly tame on a 454. For reference, here is an idle clip of a Katech torquer cam on a 427, with 12 degrees overlap at .050 (scroll down to the middle of the page):
http://www.corsaperf.com/c6_z06.htm
I'd guess your power peak would end up around 6100 - 6200 with LS7 intake, which is perfect for 6500 RPM redline.
If I were to change anything about that cam, I might open the exhaust valve a little earlier with a slightly bigger exhaust lobe and wider LSA - say, 232/244 115 LSA, or 232/246 116 LSA, either of them on about a 110 ICL.
I'd use Comp XER lobes and get a little more lift than .600, although you don't need the lift on the exhaust side as much and could go with a less aggressive lobe there. X-ER lobes are harder on springs, but if you're not spinning it to 6500 every stop light, this is probably not much of an issue.
For reference, the 454 LSx build that was done for Reggie Jackson's '69 Camaro, using GM LS7 heads, used a 236/246 110 LSA and made 640 HP, 611 ft-lb on an engine dyno. That engine used a carb-style intake - the barrel-style plastic intakes seem to like somewhat later intake valve open and close, which your greater LSA would give you assuming you use a +2 to +4 advance. Your cam works out to 8 degrees overlap at .050 - which will be fairly tame on a 454. For reference, here is an idle clip of a Katech torquer cam on a 427, with 12 degrees overlap at .050 (scroll down to the middle of the page):
http://www.corsaperf.com/c6_z06.htm
I'd guess your power peak would end up around 6100 - 6200 with LS7 intake, which is perfect for 6500 RPM redline.
If I were to change anything about that cam, I might open the exhaust valve a little earlier with a slightly bigger exhaust lobe and wider LSA - say, 232/244 115 LSA, or 232/246 116 LSA, either of them on about a 110 ICL.
I'd use Comp XER lobes and get a little more lift than .600, although you don't need the lift on the exhaust side as much and could go with a less aggressive lobe there. X-ER lobes are harder on springs, but if you're not spinning it to 6500 every stop light, this is probably not much of an issue.
D.J.
