Hey Harold, I'm looking for a recommondation of which one of your cams to run in this combination. The big change I've made with it is installing a set of mildly ported Dart Pro 1 325cc heads with 2.30 Intake and 1.88 exhaust valve. I know these heads have a real good I/E ratio and possibly now I should consider a cam change. Heres the combo:
454 .030, 12.5:1, Lunati mech roller(#50231?) .680/.700 lift, 258/268 @.050, 110 seperation installed an 108 Intake centerline, springs are 235 seat and 650 open, Vic 454 jr with a Holley 950.. T-400 with 8" 4800 stall, 4.10 gear with 28x10.5x15 QT pros, 2 1/8 into 3 1/2 super comps, 3 1/2" exhaust dumped at the rear, 3700 pounds with driver. This motor sees some NOS use up to 200HP, depending on which class I am running, but I don't want to sacrifice any N/A power for the nitrous if possible. I run a Magnaflow 500 pump with #10 line to a Max pressure Holley regulator, with two #6 lines from the regulator to the bowls. The car ran 10.90s 124mph on motor before the head switch (310cc iron Merlins)The car would 60ft 1.55, 1.53 . I'm curious with the head swap that maybe I don't need the 10 degree split in duration? Although I'm sure the nitrous likes it. smile.gif The car also sees about 100 miles a year on the street for car shows and some tinkering, so something somewhat easy on parts
Thanks, and let me know if you need additional info

RigRock,

You didn't mention your exact CR, but I have one that will work from 10.5:1 to over 13:1.
It is Lunati's 502A8LUN, 296/308 at .020, 265/276 at .050, 183/192 at .200, .710"/.710" valve lift (valve lash from .020" to .034" is OK), and a 109LSA. I put them in 102 to 105 ATDC ICL.
I have a customer on ROP(RealOldsPower.com) who has a 8° smaller one, the O288/296R9, in a 455 Olds+.060, 9.8:1, 1 3/4 headers, 4.10 and 3000 SS, and 3670 lbs, and the last I heard, he's at 10.40s, and it's a daily driver, been in for over 2 years.
I have a SBC 288/296R9, the LAST cam made at UltraDyne, to put in my own car, when I get the time and money, etc.... I will run 1.6s on it, same lift as the Olds.....
The 502A8LUN will easily accept 200 HP of NO2, and will be a very strong performer N/A. It is quite a bit fatter than your current cam at .200, and the 2 cam lobes open as if they were a 290 int and a 302 exhaust cam---This is what you see for bottom-end torque. You would have to run a Comp Cams 302-5/314-5 cam to have the same .200 numbers, and the 296 will be 24 years old in April......
Hope this helps. If you have other questions, etc, just let me know....

UDHarold

My compression is 12.5:1, which falls right into the range of the cam you were suggesting. I am curious about the big duration split,is this due to it being heavy car, running exhaust, using Nitrous? It looks somewhat close to the cam I have, I'm running .170" intake and .135" exhaust piston to valve clearance now, and with your cam being 5 degrees os so advanced may work out good then. What type of power range would it have, primarily what shift rpm would you suggest? Also is this an in stock cam, or one that would need to be ground when I order?
Thanks again

RigRock,

The actual difference between the 2 cams is enough that everyone you know will know you swapped cams. They don't even sound alike....
I consider the best power range to be 4500 to 7500, with peak power around 7000, depending on how your heads actually flow. The cam has very usable power below 4500, it will have kicked in big time by that RPM.
Remember, you have the power stroke of a 302° cam, that's putting a lot of NEW torque into your engine---More bottom-end power. You have the reversion in the intake of a 290° cam, a lot less reversion and a higher intake port velocity, packing in more air/gas, again for more torque and horspower. The high-lift area, .200" and above, is that of MUCH BIGGER cams, more BHP.
The 11° split between intake/exhaust cams will easily handle the 200 HP, even 300, NO2 shot.
Yet the unsymmetrical exhaust will not act too big on the bottom.
You'll love this cam.....

UDHarold

BTW, if you order in January, I'm sure it will be custom-made. They have over 100 new part numbers to add, and it will be some time before everything is in stock for same-day shipping, although that is ther goal.....

That cam does look really really good. I'm going to get to the track and baseline the changes I have made over the winter so far before I make the change. How is this cam on parts? Is it going to be similar to the Lunati I have in there now, or will it be a little more aggressive on the lifters, etc than what I have now?
Thanks again

...

RigRock,

The Lunati you have now is very mild. The one I recommended is more aggressive, but you should be able to get 1 or 2 seasons of racing out of a set of springs. I intend to use the 296R lobe as a daily driver in my own car. The 296 and 308 are brothers; they have the identical positive acceleration ramps. This cam should give you no trouble as far as valve-train is concerned. The main trouble it will give you is in hooking-up...

UDHarold