lstvr

I am awaiting delivery on some Dart 225's, at present i am running Comp Xr275 cam, Comp 1.85 rockers, LS2 intake manifold, 90mm N williams T Body, Straight Through silencers ( X'd), No cats, Emerald 3D Mappable fuel/ign, Tubular Manifolds but they go where they fit, and it cant be altered, not without chopping the chassis anyway, I run a TKO 600 close ratio, and i have just swapped the diff to a 3.08. What non wallet busting mods could add some more pep? By the way JUST upgrading the rockers gave 60bhp@6000rpm, with standard rockers it just dropped off at 5500. Peak overall gain was 35bhp. The heads which i am about to swap are older perimeter bolt LS1 heads, which we cc'd at 68cc. So going to 62cc Dart should give something straight off. We run 98RON fuel here in the UK. I have re asked the question because i cant find my damn thread. Sorry!

david vericker

iTrader: (1)

The X275 has only 222/224 .566 .568 and that is small cam by 383 standards.
With those heads you need a much larger cam 24X/24X or somewhere in that range.

lstvr

Do the 1.85's compensate for that? Or would you say more still?

david vericker

iTrader: (1)

The larger more aggressive cams (lobes) all call for a 1.7 ratio rockers - 1.85 ratio rollers only effect the lift (approx.+ .45) with a minimal effect on duration (+ 2*-3*) max.

david vericker

iTrader: (1)

Oops my bad, approximately +.045 increase in lift with 1.85 ratio rockers.

lstvr

Ok, i'm listening, over here in the UK theres not much no how on these LS's yet! so if i'm correct Standard cam lift is .568 on 1.7 rockers so i am .568 divided 1.7 = .334, this is then multiplied by the new rocker ratio of 1.85= .618 correct? Valve clearnance seems to be reasonably close already, i have had the Dart valves cut back by 0.75mm to be safe ( AMS racing are doing this for me.), but what kind of lift and duration can you get away with, without machining pockets? Thanks.