Now that I've been driving the engine and have the carb tuned, I'm not satisfied with what I've done. I could use a taller gear in the rear, but even with a 2200-2400 RPM stall converter, it won't overcome the low-end just drag. I put in too big of a CAM. Yeah, some will say I told ya' so, so I'm saying it for you. I have an opportunity with my leaking oil pan gasket to fix that with only the CAM cover gasket as gbauer suggests. Maybe I do a CAM swap at the same time. More work, yes, but the car will feel better.
To remind you of the specs...
- 200-4R 4-speed, 3.08:1 rear end
- Langdon iron headers, Holley 390
- 250 (conversion from 230)
- hardended exhaust seats, 1.5" stock size
- enlargened intake valves, 1.72" to 1.84"
- flat top pistons to increase compression
- 0.040" overbore
- COMP Cam 280H,
Intake & exhaust: duration: 280, duration @ .050": 230, valve Lift 0.536, lobe lift 0.306
RPM Range: 1500-5500
http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=62&sb=2I like goosing the engine, going from 1st to second the tires chirp pretty good. But getting started, even from 2200 RPM, it's super sluggish. I should've known, it needs an even bigger stall which turns out just won't work so well with how I usually drive it.
Now, the question is which CAM to go with?
Stock: (I just have a hard time going stock). But what about the torque and such?
Intake: duration: 240, duration @ .050": 192, valve Lift 0.455, lobe lift 0.26
Exhaust: duration: 248, duration @ .050": 200, valve Lift 0.455, lobe lift 0.26
RPM Range: 500-4500
http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=58&sb=2One step up, the 252H:
Intake & exhaust: duration: 252, duration @ .050": 206, valve Lift 0.474, lobe lift 0.272
RPM Range: 800-4800
http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=59&sb=2Another step up, the 260H:
Intake & exhaust: duration: 260, duration @ .050": 212, valve Lift 0.489, lobe lift 0.28
RPM Range: 1000-5000
http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=60&sb=2It seems like the 252H is the way to go, but what do I really know? I'd like to see torque improvements in the 2K-3K range.
From earlier thread...
Comparison to my stock 230
stock 230 => Torque 220 at 1600 HP 140@4400
stock 250 => Torque 235 (+7%) at 1600 HP 155@4200 (+11%)
big cam 250 => Torque 205 (-7%) at 2000 HP 246@5300 (+76%)
My big cam on the gonkulator
Torq 205 at 2000 (less than a bone stock 250!)
Torq 268 at 3800 (now it wakes up)
Powr 246 at 5300
Gonkulator Stock 250 (no other changes from above 15.82 at 85.2):
Torq 229 at 2600
Powr 154 at 3800
