cam talk

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earthmover

earthmover

in the tire smoke
Joined
Sep 21, 2007
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Location
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comp cam 306 mag
110 lc
106 intake centerline
306dura
260@50
555/555 lift

comp cam xs282s
110lc
106 intake centerline
282/290 dura
244/252 @50
520/544 lift

right now the comp cam xs282s is in the motor and runs pretty good 7.54 et / 1.67 60' and 89.0mph still need to workout some susp. problems i think...anyway the 306mag pretty close with alot of issues..the motor had timing problems which always ran hot 180/190,blown head gaskets and could never get the carb to work it ran a best of 7.70 et and 1.77 60' and 89.9 mph with all the problems..to solve the problem put in a new chain still had slack had to put in the new tensioner and problem solved. now just thinking out of the box if i could have hooked a little better with the 306 mag. like it does with the 282 it should be faster right...so do you think that if cam 2 was back in and all problems worked out like now it would be the better cam????just looking for what some of the more exp. would think on this.....8)
 
hi, in a word, no!! the 282 is a more aggressive lobe shape. plus, it develops more cylinder pressure, which = more torque, means more horse power!!
in 1/8 mile racing, torque is what you need. a longer duration cam kills cylinder pressure! thats, why you have higher compression ratio, to make up for loss of cylinder pressures. as mr. betts indicated, don't get hung up on big numbers, lobe shape is more important. thats why stockers are so fast.
a typical stocker cam looks like a roller lobe shape, and its a flat tappet design.the 282 is a good grind. the 306 is a 4000- 7000 cam. needs 11.0 comp ratio, the282 is a 2500 - 6500 range , it needs 10.1 comp ratio.
comp lists this, 282 lobe is a that maximizes torque , throttle response, very aggressive shape , feature a special closing section to eliminate noise. plus a tight lash cam.the magnums are listed as a high perform cam. just food for thought. info is from older comp cam catalog.
 
the 306 had the same amount of cylinder press. as this cam does,but keep in mind the 306 was never in the motor right cause chain slack. now i could pull the time from 32 all the way to 40 and the car would not lose or gain any thing.....blown about 2 sets of head gaskets and could never run my 950 on it the plugs would be so black.....but it was just a thought just wondering what and if there would be a diff. hay bob hows things going...if i can get myself out i'll try to grt up there to see the hot rod and meet you...im out of work right now had surgery on the 7th of this mth. sick of looking at the same walls all day......
 
hi, how does a longer duration ,more overlap cam make same cylinder pressure??? the power range is way higher vs the other shorter duration cam. unless, you're launching at 4000 RPM or higher, it isn't going to work very well!!!! any cam grinder knows, longer and bigger cams loose cylinder pressure on the overlap stroke. according to you, guess, they're wrong????
advancing probably will not help very much!!
 
if your reread the 1st post youll see that the timing was off it had that cylinder pres. then ...but i think you must have missed that part ......i know it will be a diff. cam all tog. if i was to use it but i just asked for some thought on it.......:snakeman:
 
I am no genius nor am I an engine builder, just an enthusiast but between the two I like the xs282 I plan on buying one soon for my motor and in a thread I made asking what it'd take for me to go 11's that's the cam that was recomended to me. I also like that the power comes in a little sooner rather than up at 4000. Best of luck with it, looks like your movin pretty darn good.
 
hay wigspiller74 trust me you want be mad at all this is a bad little cam,works really well with my old junk...the tq this thing makes down low is unreal...i just wanted a idea to how they would compare to one another being that cam a 282x runs like this and most it working correct an b cam 306 mag ran just as good as this one do with all the problems..now why shouldnt this cam b 306 mag work just as hard with the problems fixed...but thats just me anyway you will enjoy that cam and set up right it will go in the 11's my car gpes 7.54 ,1.67 60',@89. mph when i get the susp. worked out it will be faster..........right now it hooks then unload the tire..it'll leave a nice patt. then break lose and burn the tire up.......so its more there runs on mixed 93/111 have ran just 93...:cheers:
 
I run the 282 solid in my duster with a 410 stroker,it's a great cam and 11's should b easy with it even in a 360 with the suspension setup right.
 
Without knowing the rest I'd say the car was set up for more torque so it responds better. The convertor will react a lot different with the smaller cam too. So I'd say more than any timing issue the rest of the setup was not matched well. Just a guess not knowing all the specs.
 
hay moper the rest of the combo was
same 30' 340 block
same eagls rods and bme piston
comp cam 306 mag.
tried m1 intake/x-cel intake/and a torker 340
950hp could not tune it to work on the motor
went with a 850 custom carb that worked pretty good
same locked out dist. went from 32 deg. all the way to 40 no change
same 727 trans and 9.5 verta 5000
same 4.56 gears
had 29/10 slicks m/t on 10'' rims
went to 27/10.5qtp on 8'' rim
8gal cell
11970 duster..
now as i said the block some how has a production flaw in chain still had slack even when i order the one for linehone blocks still slack,so to fix the slack problem i put in the tensioner and never looked back....
now when i got ready to redo the motor i said hay new cam thats when i talked to bobby(thanks bobby) and came up with the comp cam 282s

306 cam track time
7.70et @89.9mph and 1.77 60'
this thing would not 60' for $hit but would run like a mad man bout 100' out so i fig. it was cause the slack in the chain by the time the time got right i was out at bout a 100 or so feet( i think now i may be wrong) im going to look at my old time slips from back then a check all my specs form start to finish.i checked the comp. alot of times it was 185 on all cylinders cause the slack i think im not saying that this cam is all that and this but just comp. times to times with what was wrong with the combo and whats right with the combo.....with all the timeslips and what nots i have for both is just one of those things where you say if this slack was not ther i could have got the thing to 60' and run faster also use the carb that i have...im not a motor builder this is my first and not my last but im learnig as i go,i used a degree wheel for the 1st time ever on this build im just comp. what my have been...all help and ideas are great and i dont know jack but some on all this board that know more and do this stuff seem to think that they are above the little guy like that trying to learn thats all i want some good old info hope that helps buddy...thanks and keep the good info comeing guys:read2:
 
Sorry... is it a 340 or a 416? What heads? Which tires were run with each cam? What intake did you settle on?
 
hay moper its a stock stroke 340, it has j heads on it,when i ran it with the 306 mag cam it had 29/10w slicks on it with the 10'' rim,and had the m1 intake on it when i made all the pass on 110 fuel no mix.

heads flow
240@500 in/140@500 ex.

sorry i forgot i had 1 7/8 headers on the motor when it had the 306 mag cam init as well...:-D
 
What is your trap rpm now? What was it before the tire change? Is the M1 still on it? What compression is it? Any exhaust beyond the headers?

So i have a combo of somewhere around 12:1(?)
XS282S
340, J heads flowing 240/140
M1 intake(?)
850cfm 4150 series Holley
1 7/8 headers
9 1/2" 5000 rpm convertor and 727
4.56s w/27x10.5 QTPs

Sound right?
 
moper said:
What is your trap rpm now? i trap now at 5000 in the 1/8 mile no 1/4 times yet./with the 306 mag it would go the 1/4 mile and trap at 7200/7400.What was it before the tire change? Is the M1 still on it? What compression is it? Any exhaust beyond the headers? i have 3'' pipes going ito flow master muff. and cut of right before the rear..

So i have a combo of somewhere around 12:1(?)///i think in the line of 11.1 i have drove this on pump 93 no problem but try to stay at a good mix maybe 5gal. 93 and 3 gal 111 in 8 gal. cell.
XS282S
340, J heads flowing 240/140
M1 intake(?) x-cal on it now
850cfm 4150 series /850 belongs to a bud my carb is the 950 hp 82 fr with 4.5 pv/88bk no pv
1 7/8 headers /1 5/8 for the low end tq.
9 1/2" 5000 rpm convertor and 727
4.56s w/27x10.5 QTPs

Sound right?
Click to expand...
hope this helps out some and thanks for all your time to help me understand or get a idea of what works and what dont ..8)
 
if you can get yor mits on a 750 you maight consider giving it a try. when i was driving my buds 340 dart sport it did not no way like an 850 on it but with the 750 it would run 11 flat. the motor was very much like yours except the cam was .600"+ lift.
 
I think, to start, that the exhaust lags and it kills power with the single pattern as opposed to the dual pattern that band-aids the weaker exhaust flow, plus the int lift stays near peak flow/air speed.
 
1wildandcrazyguy you kinda lost me there if you dont mind please exp. im all ears and eyes :read2: sorry i just reread your post and understand now...i plan to get some new head down the road but it will be for a new comb all togather...trying to max. this and all parts i have plus getting my son to drive this thing now..but please do keep all help info and thoughts comeing i love to learn and you guys have a ton of stuff for me to learn...
 
The thought was maybe you are getting in more than you are able to get out.
Say, what do the heads flow @ .550?
Have you played with more gear?

I noticed that with even my own setup, on the camquest the 282 does better # wise over the 306.
 
yea i know i just have alot of time now and thinking of ways and things to get this little car down the track as fast as i can hahaha
 
bOb shingler said:
if you can get yor mits on a 750 you maight consider giving it a try. when i was driving my buds 340 dart sport it did not no way like an 850 on it but with the 750 it would run 11 flat. the motor was very much like yours except the cam was .600"+ lift.
Click to expand...



hay bob i got a buddy thats supp. to go to the track with when weather gets right that got a aed 750ho that he may let me try before we race...he has a 347 stroker in a mustang with alum. heads nice small roller with m/t d/r on it runs real good but i think hes in trouble.hahaha anyway we plan to go to dunn bensen track he likes that track i never been so we'll see.i'll keep you posted when we go you know you always welcome to jump in.....
 
hay moper i found some of my old time slips from when i had the 306 mag in the motor
306
1.849 60'
5.089 330
7.793 et
90.195 mph

whats your thoughts on this compared to the x282s best and how it worked..it seem to me that this thing ran like hell up top,but as you can see was just a boat from the word go....
282
1.673 60'
4.837 330
7.549 et
89.476 mph

as i said before im just trying to learn from diff. specs and people that knows more about how things work..i dont want someone to shoot me down just help me thanks


just took a good look at them all and my best et was not 7.70 it was a 7.758 et
89.951 mph
1.823 60'
5.050 330 sorry for the wrong info on the other post going from mind(you can see thats going) but it been about 6yrs ago
 
any thoughts on this two slips compared to each other..
 
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