ok, so i have a d16y8 laying around from a previous swap and i've decided to strip it down and start rebuilding from scratch. i'm throwing mostly aftermarket parts on to make this little engine really run. the one question me and my buddies had was how an aftermarket camshaft would effect the VTEC system. from my view, the lobe on the camshaft that operates VTEC allows one of the intake valves to open up wider and stay open longer. the 2 lobes that operate the valves the rest of the time are only a little shorter than that lobe that works when VTEC kicks in. so, i would i think in an aftermarket camshaft, those 2 lobes for the intake valves would be longer than the stock specifications, allowing the valves to stay open longer which is where your added power comes from. but i would also think that in the VTEC engine, putting longer lobes on your intake lobes would kind of defeat the purpose of VTEC, b/c if the lobe running VTEC allows the valve to open all the way, making the 2 intake lobes the length of the VTEC lobe would be like running VTEC 24-7 b/c that VTEC lobe can't be made to be any longer than it already is. any corrections or tips would be very much appreciated, thanks guys

 

bump, i'd like to know too.

 

the vtec lobe gets bigger too, it doesnt stay the same and the others increase

 

but isn't the VTEC lobe on the stock camshaft designed to open the valve all the way? how could it get any bigger if its already as big as it can be?

 

no its not as big as it can be, it gets bigger

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by gold_ef &raquo;</TD></TR><TR><TD CLASS="quote">no its not as big as it can be, it gets bigger</TD></TR></TABLE>

all it does it keep the valves open longer, to bring in more air!!!, it doesn't get bigger!!!

 

The VTEC lobe on the cam controls both intake valves. When VTEC is not operational the two intake lobes each have a different lift. When VTEC kicks Both have the same lift and duration as each other.

The aftermarket cams improve the entire powerband not just the low profile of the cam. They do this be increasing both the lift and duration of the cam. So it does get bigger.

....and thank you all for spelling VTEC correctly...