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#1
07-11-2006, 11:10 PM
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Which Cam
Hey guys im trying to decide between these to cams. Im looking to pick up some power, and get a nice lumpy idle. Here are the 2 im stuck between.
Cam A Adv. Duration: .280°/280° Dur. @ .050'': 238°/238° Lift: .474''/.474'' Centerline: 110° Basic RPM: 2000-6000 RPM Part Number # 312-P4452992 Cam B Adv. Duration: .292°/292° Dur. @ .050'': 248°/248° Lift: .508''/.508'' Centerline: 108° Basic RPM: 2800-6200 RPM Part Number # 312-P4120233 Adv. Duration: .280°/280 They both seem to be like pretty radical cams, Im leaning twoard Cam B just cuz its alittle more extreme compared to cam A. Both cams are Mopar Performance Cams with come with lifters which is pretty cool. Heres the engine specs.. The engine was all stock.. now it has a new intake an carb. Heres the stuff..1974 Duster rebuilt 318, stock heads (which im told are the major restriction of the motor) Intake is a Edelbrock Performer 2176, the Carb is a Holley 600 cfm elec choke, Hooker Super Comp Headers. I kno the cam isnt going to make that great of difference with this setup, but he his planning on buying heads this xmas to work with everything. So what do you guys think which one will have a more lumpy idle? I will be getting new valve spring to deal with the increased lift.. how about valve clearance.. will their be any issuses with either of these cams? 
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#2
07-12-2006, 12:55 AM
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Both are lumpy and wont work worth a flip in your engine. One your carb is too small. The compression is too low and the heads wont flow enough without 360 heads and some 2.02 intake valves but you already know that. Those cams need compression to work. The 292 needs at least 10.5 to work right. The other would work decent with 9.5 to 10. If you want a cam to that will work and have a lumpy idel get a dual pattern 268* int. 272* duration cam. The dual pattern will make the heads work better wheth you keep what you have or get the better x,j,o, or u heads with 2.02 valves for your future build up. Also get a better carb in the Thermoquad.
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#3
07-12-2006, 01:40 AM
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Following dwc around.............how fun!
The later is the lumpier, but will sound real lame, when you hit the gas, if you leave the rest alone. Start from the bottom, if you want to build the power you would like. Windage tray, adviseable for high RPM, nothing like free HP's! Not to mention less air in the oil, and more oil in your stock pan. Balancing, not saying your stock bottom wont spin 6000, but, would be a nice idea, to get things balanced. To get the power from the lope, you will need to spin 6000. Pistons, without some milling, (Major) you will not get the compression you need, to work with that cam, some pop up type, would be nice, KB's are OK, I personally go forged, just my thing. Heads. Your small port heads, will work just fine with both of those cams, really. INstall some 1.88/1.60 valves in them, and some bowl releiving, and port matching/clean up. You WILL see a gain, with the big port heads, right on the top, but not a whole bunch, better to spend your money elsewhere for now, untill you can get some commando, performer, magnum type heads. IMO, at least. (yuck, smagnum heads, oh well, they do perform, even if they have rockerstuds) Valve springs, get them to match your cam lift, I like them over by a bit, say, if your lift is 500, get springs rated for 550. (recommended spring from MOPAR will be like this) HAve your valve guide shaved down too, or your seals will get mashed over time. Manifold. Performer RPM/air gap, or I like the street dominator, if you keep your small port heads. Depending on gears, a 2500 stall would be nice, maybe 3000. While I doubt the valves will get the pistons, any big cam, should be checked, NONO's with those cams, IMO........... Stock torque converter. Bigger than a 650CFM carb. (Your holley, properly tuned, will work just fine with your combo.) 2.02 valves! UNless you are going REAL extreme, for instance, my 2.02 valved 318, was 290/290 (adv) 590/615, solid roller, with a 3500 stall. I doubt the 2.02's gave me anything more really, but they were X heads. For your combo, dwc is right on the cam, buuuut, I would go with his cam as an extreme, opt for a 260 adv (212-216 .050). The idle will be barely noticable, if that is your wanting, I guess that wont do eh?. A few questions, what gears, and how fast? If you are wanting the "power sound" over the " top end power", Comp has a whole line of rough idling cams, that run good, but are designed for streetable rods. SOme work well with lower compression, and acessries, check em out! They actually look appetizing enough, that I am considering putting one in my one ton, just so I can have my chop, and pull with it too! LOL. To some of us, sound is very important. Good luck with your 318, and feel free to ask anymore questions, most of us here will have the same opinion. 
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#4
07-12-2006, 01:41 AM
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I fully agree with dwc43 about the cams; those cams are BIG in a stockish 318. You don't like the results. With the 268/272 you will still loose some low end torque, but it will be very strong from about 3500-400 rpm & up. Do what ever you can to get the compression ratio higher than stock.
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#5
07-12-2006, 05:51 AM
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Hi Lynx331;
really quickly I have a cam thats 230@.050 in a 10:1 360ci cam idles well. For a 318 would be to big. Unless you have a big gears (4.30's) and 3000+converter try P4452782 or P4452755 the largest one would be P4452761 and only if you have some gear 3.55's 2400 converter. hope this helps. rememeber it needs to work as a system you'll be happier in the long run... Denny
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#8
07-12-2006, 01:32 PM
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You will over cam that 318 with those two cams. Lumpy sound is great until you stomp on the gas and discover you have a pig.. With your set-up I would go with any of the cams listed below.
Comp 260H; 212/212 .440/.440 XE256H; 212/218 .447/.455 265DEH; 211/227 .442/.462 Lunati Voodoo cam 250/256; 208/213 .454/.454 MP -757; 211/218 .410/.425 -759; 221/228 .430/.450--For sound only if you have stock converter/gears Summit #6900; 204/214 .420/.442 Crane #693901; 204/216 .427/.454
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#9
07-12-2006, 02:01 PM
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Quote:
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#10
07-12-2006, 02:30 PM
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Stay away from the larger 360 heads and the 2.02 intake valve. Just valves alone would be a good 318 upgrade. They would be 360 valves, 1.88 - 1.60
Pocket port them for added power Otherwise, a good valve job, 3 angle for starters to help low lift flow. Mill them a bit to up comperssion to 9.0-1 max. Magnum heads are worth looking into. Aspen77RT, listed the cams good to go in your engine. Theres also enuff CFM in the 600 to feed the engine.
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#11
07-12-2006, 02:51 PM
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Quote:
Awesome selection, which one do you reccomend out of those? Hes not really into racing so i think he would a appreciate thesound more than the HP gain... when i was lookin at cams i completely overlooked the fact that his cas is a automatic and would need a converter change to work with diff cams.. I just really dont want him to be disappointed with it.. in all honesty is he really gona notice this cam if i buy it? I mean itd be kinda pointless if it does nothing for the car..
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#12
07-12-2006, 04:24 PM
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IMO,With the current set-up. Look into the Magnum heads. They will give him 1.6 rocker ratio. He needs to get some gears and converter too.
Lunati Voodoo cam (1.5 RR)250/256; 208/213 .454/.454 (1.6 RR)--------; 208/213 .484/.484 Comp Cams (1.5 RR)XE256H; 212/218 .447/.455 (1.6 RR)-------; 212/218 .477/.485
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#13
07-12-2006, 07:03 PM
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Quote:
I'd go with the xe256 but it's still kind of small for what you could run in it. Throw on a thermoquad and your good to go. 
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#14
07-13-2006, 02:29 AM
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Im running that mopar cam on my 318. I have replaced my heads with a set of new later model heads ported/polished with 1.96/1.6 values and matching mp springs for that cam.
Trans is a 904 with a 3200 stally extractors and action pro manifold 600 carb. The motor has a nice lumpy note on idle but does seem a bit sluggish down low. Top end is lots of fun tho. Thinknig the carb might be too small and am thinking of buying a street avanger 670. You can here the car idle here http://www.insanereality.org/charger/MOV01107.MPG (33m file) This was taken just after I got the car running after putting the motor back together and installing it. Had a exhaust leak (one of the exractor bolts wasnt tight enough)
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#15
07-13-2006, 03:05 AM
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Hughes Engines is the vendor who started the split duration Mopar cam craze and should be considered. I have their 504\470 cam in the 340 Duster, it idles at about 16 inches, smooth as silk with a slight rumble, never notice its there until the loud pedal is pressed then it comes on without hesitation at any RPM. Have the Straight Line performance cam behind the 360 and it performs similiar to the Hughes cam. Mopar Cams were removed from fresh engines because their performance parameters were not noticeable until approximately 3000 RPM and above.
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#16
07-13-2006, 03:24 AM
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Keep in mind not to go too hog wild on the longer exhast duration, you will lose more off idle power than a same/same cam.......
The longer exhaust seems to extend the power band a bit, and make the last stretch a bit stronger, but I like the off idle punch better than the top end. cam redline will not be as abrupt with the longer duration either.
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#17
07-13-2006, 11:15 AM
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Quote:
Keep the cam mello and in the real world of cruise RPM that YOU will drive in, or intend to drive in.
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