How big of a cam can you run on an LSx and still pass emissions?

garagedweller2 · 03-01-2009, 04:27 PM

Just out of curiosity. Thanks!

PuddleJumper · 03-02-2009, 04:58 PM

Ok so for once i can answer something lol well GM performance parts sells the LSX with an .635" is the biggest and its in the LSX 454
but i don't think that is on the market yet but the LS7 cam is and its .591" with all the requirements theses days id say that they pass if you have cats witch with these engines if you don't have cats you stupid anyway cuz they lose an lot of power with out them.

Ryan

garagedweller2 · 03-03-2009, 10:47 AM

Wait, you're making more power with cats in/.

PuddleJumper · 03-03-2009, 07:24 PM

yup if you have the cats with the Gen III and IV Small block you make an ton more power. its because they were designed to be run with cats.
the computer reads the sensors before and after the cats to make precise fuel air mixture, the computer uses "knock senors" to ajust timing or even shut of the cylinder or the whole engine if its really bad to keep the engine from knocking from poor fuel.

now the Gen I small block runs better with out cats, but im shure if you put the cat from an C6 corvette in place of an C3s cat i bet you would see an increase of performance because the new cats work better and flow better to. the exhaust manifolds are made to keep the Exhaust Gass Temp hotter to make the cat work better.

Ryan

PuddleJumper · 03-03-2009, 07:31 PM

are you looking at building an Small Block LS series engien?
what kinde of HP are you looking at making?
and what do you want for like Cid?

what do you plan on for like max RPM ie red line?