OK, interested in hearing educated opinions on these two camshafts, or similar camshafts you may have run. Educated meaning you have personal experience with cams in this size range, not really looking for people repeating what they've heard or read. Brief note on the application for those who haven't seen it: 383 LT1 with about 11:1 compression, 1-3/4" mid-length headers and 3" catback, mildly ported stock heads with 2.0/1.56 valves, 3.23 rear end and automatic with mild stall converter ( 2400 to 2800). Will have 1.6 rockers, leaning toward the ball fulcrum magnum rocker arms for long term durability. The plan is to optimize things for max. midrange power and throttle response. PULLEEEZE don't post with stuff like "that's way too small for a 383", Either of these will provide satisfactory topend power. The first is a off the shelf Comp Cams
XFI 466-8. Specs from CC are:


Intake Duration @ 050: 218
Exhaust Duration @ 050: 224
Advertised intake Duration: 268
Advertised Exhaust Duration: 276
Intake Valve Lift with 1.6 Rocker Arm Ratio: 0.570 in.
Exhaust Valve Lift with 1.6 Rocker Arm Ratio: 0.565 in.
Lobe Separation (degrees): 113

The second cam is a recommendation from a small custom cam manufacturer, not anyone that posts here as far as I know. The tech guy who designed the cam said since I'd be tuning the PCM via laptop he would close up the LSA, I wonder if a 108 might be a bit harsh. I want a smooth runner with fairly good idle. Specs are:


Intake Duration @.050: 222
Exhaust Duration @ .050: 228
Lift w/1.6: 544 536
Lobe separation: 108, with 104 intake centerline

There you have it, any feedback based on personal experience with cams in this size range is much appreciated. I haven't read up on LSA as much as I'd like yet but haven't bought my cam either. I wonder if a closer LSA, other things being equal, significantly compromises part throttle torque past a certain point. This is probably an important consideration for OEM's and they use pretty wide LSA's.

Later, Michael

 

I am very anxious to here opinions on the CC 466-8 Cam.
Especially high high it gets spun.

 

From my experiance with the current AI setup on a stock shortblock with a cam a little bigger than the second one you listed and 11.5:1 compression I think either will drive very mildly. The 108 on the second one will probably have a decent lope to it but talk to the grinder more about your concerns on that. The advertized duration and lift are similar to the GMPP 846 so maybe search some on that and see what folks have to say.

ABBA383 here ran a small Lingenfelter cam for years in a 383 with great results and one of the b-body guys ran a Comp 501(212/218) in a 383 with great results as well. You are right most here will swear both of those are too small but the FEW who have tried "small" cams in 383s really seem to have liked them.

 

I have a cam a little larger than that in my engine. I'm running at 355 cu. in. and the driving manners are very nice and only noticed a very slight loss in lowend torque (mainly off-idle power). I get a little bit of a tug when coming to a stop due to still having the stock converter and a raised idle (750 rpm in gear). With you having more cubes and a milder cam the idle should be fairly mild and you will have TONS of lowend torque (more so the first cam than the seconnd). I drive my Camaro to work whenever the weather is nice and have had zero issues with it. I have a bit of a lopey idle, but with you having more cubes and a milder cam I'd think you should be getting a "stock-like" idle with either cam.

 

What does your car shift at?

 

I'm running the CC503 XE cam (224/230-112) with 1.5RRs in my 383 - a similar engine build to your's with ported, larger-than-stock valve heads. It's quite mild, has a torque "curve" as wide and flat as the praries, and can easily be a DD. My car's an M6, and although the engine revs freely to 6900, I've found ~6200 to be an optimal shift point as the power starts falling off after that with my setup. It's as happy at 1500RPM in 6th as it is winding out in 1st... shifting gears is done more for fun than necessity. The car/engine drives like a "factory" performance car, and fuel economy is surprisingly good.