denny411 Posted January 19, 2003 Share Posted January 19, 2003 I`m trying to decide what cam I should use for the Z. Is there some *MAGIC* formula somwhere that could help me accomplish this? I prefer a solid roller design. The engine is a 383 sbc completely balanced with 10.5:1 comp, The intake is a Edelbrock Victor junior, with a 750 holly DP. It currently has (mildly ported/matched)Dart sportsmanII heads w/ 2.02/1.65 valves, and 200cc intake runners, but I may change to aluminum pro1`s. The car will be approximately 2700# with driver, and I plan to run a 200R4 trans with a 2500 or 3000(not sure) stall converter w/ lockup, and an R230 diff w/3:55 gears. The car will be dual purpose, with emphasis on 1/4mi performance. I may also put a 125hp nitrous kit on for a little extra punch. I`m hoping for about 450hp on the motor and about 550 w/ the bottle. Quote Link to comment Share on other sites More sharing options...
Mudge Posted January 19, 2003 Share Posted January 19, 2003 Without flow numbers on the heads it would be guesswork, intake runner info all comes into play also, as well as header runner length and a bunch of other BS go into estimating horsepower. With some headflow and intake info though good guesses can be made. Quote Link to comment Share on other sites More sharing options...
denny411 Posted January 19, 2003 Author Share Posted January 19, 2003 Flow numbers unported at .500 lift, Intake 240, Exhaust 164. I`m using 1 3/4" fenderwell headers with 3 1/2" collectors. I will also be running 3 1/2" sidepipes. I did find this on another web site. Typical Application Street: 274 Cam: 230/236° .487"/.490", Dart II Sportsman #061010 dual plane intake; 750 cfm carb, 1-3/4" header. 430HP on 9.8:1 355; 480HP on 383 10.5:1 (varies with displacement and compression ratio). I`m not sure who makes the cam specified though.(SH 274) Does anyone recognize the SH prefix, or who the manufacturer might be? I would like to know the rpm range of this particular cam, and what the tourque curve would be. Quote Link to comment Share on other sites More sharing options...
Mudge Posted January 19, 2003 Share Posted January 19, 2003 A 50 HP jump sounds like wishfull thinking, 355 vs 383. This will be a hydraulic flat tappet? I ran a similar cam, but in an FI, hyd roller, LT1 with better heads and made 411 RW with an ignition miss, was banking on 490+ at the crank. I would say your in the right neighborhood, but I will admit I'm weak on RPM range info with flat tappet stuff. If you have the money for the bottom end work though, I might work on the heads a bit more, but it depends how picky you are I guess. I felt like it was more important to have the top end than the bottom, although the torque advantage would be in your favor. Quote Link to comment Share on other sites More sharing options...
denny411 Posted January 19, 2003 Author Share Posted January 19, 2003 My bottom end is completely finished, with Steel four bolt caps, eagle rods, main studs, head studs, and steel crank. I`ve already got these heads, so all I really NEED is the cam and springs to match. I`m hoping to get low to mid 10`s on the bottle. Quote Link to comment Share on other sites More sharing options...
denny411 Posted January 19, 2003 Author Share Posted January 19, 2003 The page I got the info from stated that it was a ROLLER cam. I`m going to call them on monday and see what`s up, and where I can get the cam they list. I really would PREFER a roller cam. I already have the lifters so the expense wouldn`t be outragious. The difference between the engines is the 383 w/ 10.5 comp,has 1.25 hp per ci, and the 355 w/ 9.8 comp has 1.2 hp per ci. That doesn`t sound too far fetched to me. Quote Link to comment Share on other sites More sharing options...
Mike C Posted January 19, 2003 Share Posted January 19, 2003 For a max engine speed of 6500 rpm, check out the Comp 280AR Magnum solid lifter cam. I have one of these in my 355. It has probably 15k miles on it or so with no durability issues. It pushes my 3500# car to 12.7's at 110 mph ( 2.0 short time ), idles at 800 rpm at 12". Pulls hard from 2500-6500 rpm. 280/280 advertised, 236/236 @ .050 and .550 gross lift, I lash intake and exhaust .020, but next lash I think I'm going to tighten the intake up to .018. Quote Link to comment Share on other sites More sharing options...
Mudge Posted January 19, 2003 Share Posted January 19, 2003 Ok, roller lifters are mo betta I wasn't sure if you had the machine work for it, or had a modern SBC or what. I'm going to make a guess at 470 HP or better, if tuned right. Quote Link to comment Share on other sites More sharing options...
z ya Posted January 19, 2003 Share Posted January 19, 2003 The cam they are talking about is the comp cam extreme energy 274. It is 274/286 and 487/490. At .050 is 230/236. The rpm range according to comp cams is 1800 to 6000 rpm. Recommended stall is 2200 rpm. Good luck! Quote Link to comment Share on other sites More sharing options...
Mudge Posted January 20, 2003 Share Posted January 20, 2003 Thats kind of what I thought, usually they are 224/230, 230/236, 236/242 etc, but they should be labled XE I believe (at least for rollers). Power falls off VERY quickly if you over-rev them, so plan on sticking within the powerband that shows up on the dyno. There is argument as to how hard they may be on springs/lifters for that little bit of bottom end improvement, so keep that in mind as well. Quote Link to comment Share on other sites More sharing options...
denny411 Posted January 20, 2003 Author Share Posted January 20, 2003 Good reading on the XE cams. http://www.streetrodstuff.com/Roundtable/Archives/Year_2001/November/35.php Quote Link to comment Share on other sites More sharing options...
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