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Discussion Starter #1
I've been trying to figure out a possible "rule of thumb" for overlap on cams that will pass smog. I've been told that the more negative overlap the better for passing but it also depends on the size of the cam so I have 6 possible grinds in mind. Let me know what you think would have the easiest time passing smog while making the most useable power. I have the same lift on all the cams as a point of reference, it is subject to change depending on what cam will work th best.

216/216 .585/.585 110 has -4* overlap
216/216 .585/.585 112 has -8* overlap
218/218 .585/.585 110 has -2* overlap
218/218 .585/.585 112 has -6* overlap
220/220 .585/.585 110 has 0* overlap
220/220 .585/.585 112 has -4* overlap

I'm hoping anyone with knowledge on cams that can pass smog in Cali can help or just anyone that knows cams in general. Thanks to anyone that can help me with this matter.
 

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HOT AIR BALLOON OWNER
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Run this - 216/216 .585/.585 112 has -8° overlap, 110°ICL.

Less lift, the heads start to level out after 0.540 anyway.
 

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if I remember right split duration cams are not a good idea to pass smog, I think you want a higher intake than exhaust duration such as a 224/216 or something to that extent. Look up the ls7 cam it has a huge split in duration so it can pass smog. Also you'll need a high lsa like a 116 if you want to run anything over a 210*
 

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Discussion Starter #4
I think I am just going to say screw it and put in a big cam right after my smog test this year and then just swap it for stock when I have to test again in 2 years.
 

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HOT AIR BALLOON OWNER
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if I remember right split duration cams are not a good idea to pass smog, I think you want a higher intake than exhaust duration such as a 224/216 or something to that extent. Look up the ls7 cam it has a huge split in duration so it can pass smog. Also you'll need a high lsa like a 116 if you want to run anything over a 210*


I've seen cars with 220-224 intake still pass. It's all in the tune.

Any of the small cams will be fine. The lil 212/218 would pass easily, a 216/224 will, etc. I've seen plenty small like 206/214 on a 112LSA pass too.



The LS7 does have a huge split favoring the exhaust side and a gigantic LSA. Just like the LS6 cams, they're what... 204/214 on a 117 or something insane.
 

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HUNTING
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224/224 on a 114 is the biggest that will pass. Anything under that is fine as well.

Do a search on LS1tech.com, lots of information about this over there.
 
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