383Ci 222/224 cam+ 1.85 rockers?

**lstvr** · 12-11-2007, 09:49 AM

Hi Guys, I have a 383Ci with an XR 275 Comp Cam, plus 1.85 comp rockers, this adds up to .615/.618 lift with 222/224 112lsa, i also have an LS2 inlet manifold and a 90mm N Williams TB, Dart 225 heads, 1"3/4 headers no cats, twin 2.5" system. The question is should i be aiming for more valve duration? The lift is pretty big with those rockers is it not?

**nhraformula** · 12-11-2007, 10:22 AM

i would do a clay test to see if you have clearance with the pistons.

**lstvr** · 12-11-2007, 11:56 PM

Minimum clearance is .1457 so that should not be an issue. Cheers.

**Frost** · 12-12-2007, 07:33 AM

224 in a 383? You pull stumps with that thing?

A4 or M6? If A4, what stall? What gears in the rear? Will you be keeping that intake?

**lstvr** · 12-13-2007, 12:49 AM

Its in a TVR Cerbera, 5 speed manual. 3.08 Diff, TKO 600 gearbox. Car weighs 1200KGS whatever that is in pounds!? Keeping the intake for now.

**Frost** · 12-13-2007, 04:22 AM

just googled that.... never even heard of the car before... 1200kgs = 2600lbs... REAL light (1Kg = 2.2lb)

A car that light could really benefit from a larger cam, but a lot of it is to taste. Do you drag race this car or just cruise around? What are you looking to gain exactly? Nice lookin ride, btw.

**lstvr** · 12-13-2007, 06:25 AM

Its a road toy, i have dragged it once 12.3/120mph, wheelspin was a problem off the line, that was with the old 806 ported heads, i've not ran it with the darts yet. I have to take the engine out to swap the cam, so its something i am thinking of a bit later on, when i swapped the rockers from stock it made a MASSIVE differance as the top rev range came alive. Like i say i have quite alot of lift but mildish duration, what sort of duration do people usually go for on a 383?

**02blkws6** · 12-13-2007, 06:32 AM

Not enough duration for the cubes IMHO.

I wouldn't go less than 230 duration for mild, 240 mild/wild, and 250 straight wild.

**Frost** · 12-13-2007, 09:56 AM

Originally Posted by 02blkws6

Not enough duration for the cubes IMHO.

I wouldn't go less than 230 duration for mild, 240 mild/wild, and 250 straight wild.

That sounds pretty close... remenber the cubes make the cam "feel" a bit smaller, as most seem to base thier cam-feel off of a stock-inch motor.

Keep in mind if you make the swap you will almost certainly have to return to a stock-ratio rocker.

**lstvr** · 12-13-2007, 10:30 AM

I was thinking of custom grind to take into account of the rockers, so i could still use them rather than have to go and buy another set, so in effect similar lift cam to current one but more duration?