All,
Thanks for your advice so far. I know cam selection is a recurring theme, but since every application is a little different, I thought I'd seek your inputs. Chassis, trans, and short block and exhaust are done deals, all other components (except Hyd Roller Cam and engine accessories) are open to recommendation. Here's the skinny:

'68 SRIII based roadster w/C4 susp, steering and brakes
Rearend - D44 w/3.45:1
TKO 600 w/2.87, 1.89, 1.28, 1.0, and .64
Vehicle weight is a guess, but likely 3000-3100 lbs.
Engine:
- Dart SHP w/forged Eagle/SRP (4.155x3.75), 5.7" H-Rods w/9.7:1 static comp
- AFR 195 Eliminator Street Heads (stock) (will consider spring changes)
- Edelbrock RPM Air Gap (matched to 1205 gasket)
- Aftermarket TBI or Holley 750 mech secondary DP (undecided)
- Hooker Super Comp Side Exhaust (most likely reverse flow mufflers)
- Windage tray pan, aluminum water pump and radiator, electric fans
- MSD Ign
- Pwr Steer, Pwr Brakes, Aftermarket A/C
- 1.6 roller rockers (TBD)
- Hyd roller cam using new factory lifters and spider

Street only car. Not a daily driver, but more than weekend only. Must allow Pwr Steer, Pwr Brakes, Aftermarket A/C. Need to consider Hooker exhausts flow, or lack thereof (don't know how much the single vs dual pattern design effects this.) Wanting great throttle response, powerful bottom end, optimized midrange, and able pull up to 6000 RPM (at least I think). Lope is good, but nothing too radical. Please consider a recommendation for both Carbed and compatibitly with FAST EZ or Powerjection III ECUs. Hope this is enough to go on. Hardly important, but I like the ring of "Lunati Roller."

Thanks in advance,
Rob

 

are the reverse flow inserts a must have? or are you willing to bend on that one?

 

I have the same question. They will cost you 100 HP. Maxfow or Spiral turbo baffles are a much better option for your build. Looking for good street manners and a broad flat power curve? This will work with your carb and/or fuel injection.

http://www.compcams.com/Cam_Specs/Ca...?csid=209&sb=0

You will give up a little peak HP with the wider LSA but streetability will improve noticably and the torque curve will be very flat. Lunati's choices are limited unless you go custom grind.

 

No problems with changing the exhaust inserts. A little loud and obnoxious is better than too quiet. I just don't want it rediculously (race car or big-inch V-twin with drag pipes) loud. Maybe 60-80% of that level is ok. I don't see myself laying into it like I have a tendency to do on a bike--at least not as often. Thanks for the inputs so far.

Will un-corking the exhaust change that cam recommendation?

 

63mako,

You said it better than I could have. Peak HP is not a concern. Broad flat power curve is the goal. Street grunt and blasts up to 80mph.

If I ever run a 1/4, it will just be a one-time fun-run. I do see a few 20mph roll-ons, winding canyons and empty parking lot olympics in my future though.

Will a desktop dyno give a decent idea of hp/torque curves?

Thanks again.

 

All,

I've spoke with a rep at both Comp and Lunati. The Comp 280 XFI does look like it would work well for my goals. Lunati will custom grind a single-patter 282 Voodoo for the same price as standard. Its listed last. The Lunati cam specs are for 1.5 ratio rockers and the Comps are based on 1.6. I added the numbers in brackets next to the Gross Valve Lift lines. One option is for a standard 282 Voodoo cam with mixed ratio rockers. Anyone with AFR 195 Eliminator Street cam knowledge have any inputs? How do you think they compare?

Thanks,
Rob

LUNATI 282 VOODOO
• Advertised Duration (Int/Exh): 282/290
• Duration @ .050 (Int/Exh): 231/239
• Gross Valve Lift (Int/Exh): .535/.550 (.569/.585)
• Lobe Lift (Int/Exh): .356/.366
• LSA/ICL: 110/106
• Valve Lash (Int/Exh): Hyd/Hyd
• RPM Range: 2400-6200

LUNATI 282 VOODOO (1.6/1.5 Ratio Rockers)
• Advertised Duration (Int/Exh): 282/290
• Duration @ .050 (Int/Exh): 231/239
• Gross Valve Lift (Int/Exh): .535/.550 (.569/.549)
• Lobe Lift (Int/Exh): .356/.366
• LSA/ICL: 110/106
• Valve Lash (Int/Exh): Hyd/Hyd
• RPM Range: 2400-6200

COMP XFI 280
• Advertised Duration (Int/Exh): 280/288
• Duration @ .050 (Int/Exh): 230/236
• Gross Valve Lift (Int/Exh): .576/.570
• Lobe Lift (Int/Exh): .361/.358
• LSA/ICL: 113/109
• Valve Lash (Int/Exh): Hyd/Hyd
• RPM Range: 2000-6000

LUNATI 282 VOODOO (Single-Pattern) (w/1.6 rockers)
• Advertised Duration (Int/Exh): 282/290
• Duration @ .050 (Int/Exh): 231/239
• Gross Valve Lift (Int/Exh): .569/.569
• Lobe Lift (Int/Exh): .356/.356
• LSA/ICL: 110/106

 

The 110 LSA with that duration might give you fits tuning with FI. That is why I recommended the XFI cam. FI is easier to dial in with a wider LSA. Low and midrange throttle response will be better also(see operating RPM)

 

I agree with 63mako on the lsa for FI......if you want broad flat power curves...that lunati cam on a 112lsa will do the job (especially for a carbed setup)....also help with street manners too. I would also do a 1.6RR on both sides regardless, to up the lift and you'll get the most out of those heads. I would not go with single pattern cam...can't remember why, but when I was going through cam choices on my motor with AFR heads, the single pattern cam was out.

 

your engine is very close to what I have.

406, 10/1 comp, 5.7 rods,SRP pistons, roller cam, 1.6 rockers, all balanced, differences are I have vortec heads, edelbrock performer intake, and a reworked quadrajet. I built my engine for torque and rpm limit of 6000rpm. I used a comp xr276hr 224/230@.050 with .535" IN /.544" EX with the 1.6 roller rockers.
I'm very happy with the performance this package gives me. It idles nicely with a good lope, 14" vacuum at 800 RPM idle- all accessories work very well, and I haven't done any real tuning on it yet.
I only have about 375 miles on it so far and I can tell you with my 3.36 gears and .64OD in the tko 600 this combo has no problem cruising down the highway at 2000 RPM at 70 MPH. You will have to be careful about choosing too large a camshaft that won't allow you to cruise in OD down the highway......if you do alot of that, which I do.
Here is a clip of my combo doing a 0-100 MPH run....didn't even get out of third gear..... the run is at the end of the video

 

Thanks. Looks like the 280XFI gets the nod. I did see a GM Performance article on LT1 Aftermarket Head comparisons where they used that cam. It was a Ported LT1 style EFI,11:1, 383 that made 515hp and 480 tq in the mid-to-upper range with AFR 195s.

Since I haven't decided on carb vs EFI this looks like a great fit. Better low range throttle response is also a selling point.

Rob

 

You will be very happy with this cam for your goals. Bet you are right at 500 HP and 500 Ft Lbs of torque maybe a little more. Torque will kick in early and pull strong to redline.