Help a newbie understand cams....
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Help a newbie understand cams....
Hi
I'm going to be buying a 02 C5Z early next year, and I'm already considering some mods for it!
I'm looking for improved acceleration for around the track, power under the curve, between 2000 and 5000 rpm. I hear a small cam is best for this range of increased power.
Sure the Z will be better than I can cope with, but I'm always looking at the next step....
I'm considering 1:8 roller rockers so I don't have to tear into the internals, and see they could offer an increase from around .550 lift to .580 , an additional 0.030" of lift at both the intake and exhaust valves.
The piston to valve clearance gets tight with a 1:85 on the 02 + LS6, so 1:8 is as high as I'd go.
I'm hoping someone can fill in some blanks for me so I can compair the rr and the extra power in comparision to camshaft gains??
LS6 cam 204/218 duration 0.551/0.547 lift, on 117.5 LSA
LS6 + 1:8 rr ______? duration 0.580/0.575 lift?, on ____? LSA
Small cam 224/224 duration 0.551/ 0.551 lift, on 114 LSA
Medium cam 232/234 duration 0.595/ 0.598 lift, on 112 LSA
Big cam 236,240 duration 0.630/ 0.612 lift, on 111 LSA
I'm still don't have a full understand of camshaft numbers, but if someone could fill in these numbers I'm sure it would put another piece of the puzzle in place for me.
Thanks for the help
I'm going to be buying a 02 C5Z early next year, and I'm already considering some mods for it!
I'm looking for improved acceleration for around the track, power under the curve, between 2000 and 5000 rpm. I hear a small cam is best for this range of increased power.
Sure the Z will be better than I can cope with, but I'm always looking at the next step....
I'm considering 1:8 roller rockers so I don't have to tear into the internals, and see they could offer an increase from around .550 lift to .580 , an additional 0.030" of lift at both the intake and exhaust valves.
The piston to valve clearance gets tight with a 1:85 on the 02 + LS6, so 1:8 is as high as I'd go.
I'm hoping someone can fill in some blanks for me so I can compair the rr and the extra power in comparision to camshaft gains??
LS6 cam 204/218 duration 0.551/0.547 lift, on 117.5 LSA
LS6 + 1:8 rr ______? duration 0.580/0.575 lift?, on ____? LSA
Small cam 224/224 duration 0.551/ 0.551 lift, on 114 LSA
Medium cam 232/234 duration 0.595/ 0.598 lift, on 112 LSA
Big cam 236,240 duration 0.630/ 0.612 lift, on 111 LSA
I'm still don't have a full understand of camshaft numbers, but if someone could fill in these numbers I'm sure it would put another piece of the puzzle in place for me.
Thanks for the help
Last edited by taws6; 09-25-2010 at 10:56 AM.
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Thanks for the link and reference, but most of that info just goes a little over my head, even though I've read it numerous times...
I 'Think' I've calculated the lift (in red), but can't see how to calculate the intake and exhaust figures for the LS6 with 1:8 rr.......
I 'Think' I've calculated the lift (in red), but can't see how to calculate the intake and exhaust figures for the LS6 with 1:8 rr.......
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Thanks for your replys.
I know a cam would be a better bang for the buck, but the 1:8 rr would be much easier to install.....
Can anyone fill in the missing figures above???
Thanks for the help
I know a cam would be a better bang for the buck, but the 1:8 rr would be much easier to install.....
Can anyone fill in the missing figures above???
Thanks for the help
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to answer your duration question
all you do is take the stock #, divide it by the stock rocker ratio (1.7), and then multiply that number by 1.8
that will give you the difference between 1.7 and 1.8 rocker arms
I agree with the guys above, do a cam swap, if you do your research, you'll be more than happy. Don't just listen to guys that say "buy this cam, its better than this other one, blah, blah, blah..." Do some research in the dyno section, there are a lot of good visuals there. The biggest thing, set a goal for the car, that way you have something to work towards. Just my $.02 though.
Austin
all you do is take the stock #, divide it by the stock rocker ratio (1.7), and then multiply that number by 1.8
that will give you the difference between 1.7 and 1.8 rocker arms
I agree with the guys above, do a cam swap, if you do your research, you'll be more than happy. Don't just listen to guys that say "buy this cam, its better than this other one, blah, blah, blah..." Do some research in the dyno section, there are a lot of good visuals there. The biggest thing, set a goal for the car, that way you have something to work towards. Just my $.02 though.
Austin
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to answer your duration question
all you do is take the stock #, divide it by the stock rocker ratio (1.7), and then multiply that number by 1.8
all you do is take the stock #, divide it by the stock rocker ratio (1.7), and then multiply that number by 1.8
So the figures would look something like this??
LS6 cam 204/218 duration 0.551/0.547 lift, on 117.5 LSA
LS6 + 1:8 rr 216/230 duration 0.580/0.575 lift?, on ____? LSA
Small cam 224/224 duration 0.551/ 0.551 lift, on 114 LSA
Medium cam 232/234 duration 0.595/ 0.598 lift, on 112 LSA
Big cam 236,240 duration 0.630/ 0.612 lift, on 111 LSA
That would make the exhaust duration longer than the small cam, is that right??