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Re: At risk of being retarded
[Re: MR_P_BODY]
#228560
02/18/09 12:09 PM
02/18/09 12:09 PM
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Joined: Oct 2007
Posts: 4,205
New York
polyspheric
master
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master
Joined: Oct 2007
Posts: 4,205
New York
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Typo?
Intake valve closes sooner.
Boffin Emeritus
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Re: At risk of being retarded
[Re: polyspheric]
#228562
02/18/09 03:57 PM
02/18/09 03:57 PM
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Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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Quote:
Typo?
Intake valve closes sooner.
Sorry about that... I just seen it... thanks for the catch
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Re: At risk of being retarded
[Re: hemi471]
#228565
02/18/09 07:15 PM
02/18/09 07:15 PM
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Joined: Jan 2003
Posts: 28,596
Shopping @ HoBo Fright
340SIX
Doc Flappergas's Evil Twin
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Doc Flappergas's Evil Twin
Joined: Jan 2003
Posts: 28,596
Shopping @ HoBo Fright
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Quote:
Also alot of cams are ground 4 deg advanced, so when you install it straight up its advanced 4 deg. I called Comp Cams and found this,at least on the one they sold me.
both my engle cams soild and hdy were ground 4 degree advanced.
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Re: At risk of being retarded
[Re: rowin4]
#228567
02/18/09 10:18 PM
02/18/09 10:18 PM
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Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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Yes alot/most cams have 4 degrees of advance ground into them, I still advance them another 4 to 6 degrees on top of what they say for the installed degrees, specially on small blocks that need the added torque
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Re: At risk of being retarded
[Re: RAT PATROL]
#228569
02/19/09 11:55 AM
02/19/09 11:55 AM
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Joined: Mar 2006
Posts: 9,910
Eighty Four, PA
B G Racing
master
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master
Joined: Mar 2006
Posts: 9,910
Eighty Four, PA
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Cam setting is based on the overall combo.From the engine build to drivetrain gearing,chassis and desired power range,using weight,HP&torque,gearing,tire size,shift rpm,trap rpm and calculated MPH.Other reasons maybe for piston to valve clearence and cylinder volume pressures.That a cam should be advanced or retarded,you must analyze your complete combo and calculate where your power and torque curve will best benifit your antisipated performance. 
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Re: At risk of being retarded
[Re: emarine01]
#228571
02/19/09 06:11 PM
02/19/09 06:11 PM
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Joined: Dec 2008
Posts: 1,200
UK
602heavy
pro stock
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pro stock
Joined: Dec 2008
Posts: 1,200
UK
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Advancing the ICL will fool the motor into thinking it has a smaller cam , considering most cams have more duration than necasary (big is not always better) , then in most appliications advancing the ICL will yield more power as the motor will build more cylinder pressure.
I advanced the ICL 8* (108 lobe sep)& went from a 1.6 to a 1.5 60ft , fitted another cam (112 lobe sep) on the assumption the 108 lobe sep was dumping most of the nitrous out the tailpipes @ overlap , picked up another 2/10ths & got me into the 10s.
Last edited by 602heavy; 02/19/09 06:12 PM.
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Re: At risk of being retarded
[Re: 602heavy]
#228572
02/19/09 08:04 PM
02/19/09 08:04 PM
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Joined: Jan 2007
Posts: 3,695
nc
emarine01
master
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master
Joined: Jan 2007
Posts: 3,695
nc
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Thanks for the info, trying to get a good grasp on valve timing for my rig, I have been running 2 cams small and large and trying to figure it out by seat of the pants, Seems a lot of guys are running wide lsa with a lot of advance , still trying to get a feel for cyl preassure,lsa & advance, the simple thing is go with a 108lsa on 104 lots of cams built that way but not looking for much power under 5000, still dont know if 108 lsa in on 108 or 110 on 106 , which one is better for me? Sorry if I stomped on someones thread but the questions are closely related
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Re: At risk of being retarded
[Re: emarine01]
#228573
02/19/09 09:05 PM
02/19/09 09:05 PM
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Joined: Jan 2005
Posts: 1,260
Las Vegas NV
moparmanjames
pro stock
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pro stock
Joined: Jan 2005
Posts: 1,260
Las Vegas NV
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Just a quick explanation of camshaft lobe separation, The tighter the lobe separation, the more peak torque you will have for a camshaft with otherwise all other specifications identical. For example, say you have a basic cam, 230 @ .050" and .500" lift with 1.5 ratio rockers. If this cam were ground on a 114 lobe separation angle, you would have a relatively flat torque curve with good vacuum and idle behavior due to minimal intake and exhaust valve overlap. Now take the same cam and tighten the LSA to 112*, the torque curve has become somewhat hill shaped compared to before, with a higher peak torque but it drops off quicker as the rpms increase there is a slight lope to the idle. Take it to 110* and now it's getting peaky and higher torque with a definite drop off not far past peak torque, a very noticable lope and idle vacuum is falling. Now we go to 108* and the graph now looks like a mountain with torque climbing to a large peak fast but falling off fast as well, choppy idle from excessive overlap and we are needing to up the idle rpms to keep it running in gear with a stock converter. This is due to closing the intake valve earlier and earlier as the lobes get closer together, this increases overlap so idle vacuum goes down but midrange power skyrockets. To compensate for losing power in the higher rpm range, we just increase duration to keep the valves open longer. so you have to decide on an engine compromise between manners and barbarism.  This is a very basic explanation and wider lobe separation does have its place in performance, it's all in the application and what you are trying to do, but just remember the rule of thumb is the wider the lobe separation, the flatter the torque curve across the rpm range, so if you want a flat torque curve but also alot of torque then you must raise the cylinder pressure either with compression or forced induction or nitrous.
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Re: At risk of being retarded
[Re: moparmanjames]
#228574
02/19/09 09:32 PM
02/19/09 09:32 PM
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Joined: Jan 2003
Posts: 17,918
Akron, Ohio
ProSport
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 17,918
Akron, Ohio
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I have always installed my solid cams a couple degrees advanced with great results. My new short block came with a roller cam by CamMotion, I called CamMotion and he said my 705/661 281/283 cam is on a 104, he had me degree it in at 106 as he thought 104 with my 500" 440-1 headed combo would be all bottom end and less top end so I put it in at 106, especially since I'm running a true 10.5" tire. We'll see how it goes. 
1970 Challenger, all aluminum 528 Hemi, HDK suspension, Tremec 5 speed manual
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Re: At risk of being retarded
[Re: moparmanjames]
#228575
02/19/09 09:48 PM
02/19/09 09:48 PM
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Joined: Jan 2007
Posts: 3,695
nc
emarine01
master
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master
Joined: Jan 2007
Posts: 3,695
nc
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Nice post, thanks- My goal is to carry as much torque to 7k as possible with 12 to 1 comp my comp solid roller 260@.05 106 on 106 is a little too peekey , good @ 55 to 6k but falls flat by 6500 with big mud tires , the 280@ .050 107 0n 103 doesent have enough @ 5500 I think its too much duration for 12 to 1 trying to pick a cam in between around 268@.050 but cant get a grasp on lsa the 108 will still be peekey I think so I was looking at 110 and advanving it 4?
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Re: At risk of being retarded
[Re: emarine01]
#228576
02/19/09 10:52 PM
02/19/09 10:52 PM
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Joined: Dec 2008
Posts: 1,200
UK
602heavy
pro stock
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pro stock
Joined: Dec 2008
Posts: 1,200
UK
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A cam ground with a 110 lobe seperation angle will in most cases be installed 4* advanced , this puts the intake centre line @ 106* & the exhaust centre line @ 114* , some say the reason for this is to allow for chain stretch  , the cam card will say @ what CL the cam should be installed (if 112 lsa then they want it installed @ 108), is this what you're asking?
Last edited by 602heavy; 02/19/09 10:55 PM.
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Re: At risk of being retarded
[Re: emarine01]
#228577
02/19/09 11:58 PM
02/19/09 11:58 PM
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Joined: Jan 2005
Posts: 1,260
Las Vegas NV
moparmanjames
pro stock
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pro stock
Joined: Jan 2005
Posts: 1,260
Las Vegas NV
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Quote:
Nice post, thanks- My goal is to carry as much torque to 7k as possible with 12 to 1 comp my comp solid roller [Email]260@.05[/Email] 106 on 106 is a little too peekey , good @ 55 to 6k but falls flat by 6500 with big mud tires , the 280@ .050 107 0n 103 doesent have enough @ 5500 I think its too much duration for 12 to 1 trying to pick a cam in between around [Email]268@.050[/Email] but cant get a grasp on lsa the 108 will still be peekey I think so I was looking at 110 and advanving it 4?
So first, you say you want to carry as much torque to 7000 as you can, so does this mean you want your HP to peak at 7000 or do you want to shift at 7000?
I think you are on the right track with the 110-112 lsa with 270* or so @ .050".
If you can give me a run down of your engine I will throw it on my dyno program and see which cam will be best.
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Re: At risk of being retarded
[Re: moparmanjames]
#228578
02/20/09 12:47 AM
02/20/09 12:47 AM
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Joined: Jan 2007
Posts: 3,695
nc
emarine01
master
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master
Joined: Jan 2007
Posts: 3,695
nc
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I trying to pull faster in high gear between 6500 & 7k the 260 cam pulls it a little too slow , only need 7k max rpm , The engine is 414 small block 12 to 1 with flat tops W5 325@.650I 235@.650e current cam comp solid roller 260/262@ .05 .631 lift with 1.5s 106lsa on 106 , we run .058 quench for bme rods , truck weighs 3250 / 3500 with me , 5k stall , 727 w stock ratios 3.90 x2 gear ratio with 38.5 tall x 15w tires
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Re: At risk of being retarded
[Re: mopardamo]
#228581
02/21/09 12:17 AM
02/21/09 12:17 AM
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Joined: Jan 2007
Posts: 3,695
nc
emarine01
master
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master
Joined: Jan 2007
Posts: 3,695
nc
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In mud racing you need all your power in asap , we only go 200ft , we went from a 38.5 x11w rear tire to a 38.5 x 15w and slowed the truck dowm 2,5 tenths , the wide tire launches better and truck handles a lot better, the problem is in high gear there is a lag in the rev to 7k , engine hits 6500 instantly with the wide tire , with the skinny tire we hit 7k instantly , trying to cam up to the best cam for my rig hoping to correct the power lag , 7k is all the wheel speed I need with tire dia and gears, I know I need a little more duration maby 265 to 270 range but trying to widen power band also thats where i am having problems with witch lsa to choose.
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Re: At risk of being retarded
[Re: emarine01]
#228582
02/21/09 02:06 PM
02/21/09 02:06 PM
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Joined: Jan 2005
Posts: 1,260
Las Vegas NV
moparmanjames
pro stock
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pro stock
Joined: Jan 2005
Posts: 1,260
Las Vegas NV
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Quote:
In mud racing you need all your power in asap , we only go 200ft , we went from a 38.5 x11w rear tire to a 38.5 x 15w and slowed the truck dowm 2,5 tenths , the wide tire launches better and truck handles a lot better, the problem is in high gear there is a lag in the rev to 7k , engine hits 6500 instantly with the wide tire , with the skinny tire we hit 7k instantly , trying to cam up to the best cam for my rig hoping to correct the power lag , 7k is all the wheel speed I need with tire dia and gears, I know I need a little more duration maby 265 to 270 range but trying to widen power band also thats where i am having problems with witch lsa to choose.
Well after I punched the numbers in I saw that you definitely picked up on the top end with a wider LSA but with that came less torque @ 5500, so I decided to go the other way and tighten the LCA but increase duration.
Lunat makes a nice grind the SBMopar 50415 Roller.
Specs are .636 lift with your rockers, 104 lsa on a 102, and 276* duration. I don't have your heads in my database so I was using some Indy's with similar flow, but this cam made more torque and HP from 5500 to 7000, and if you want to give up a tiny bit of torque at 5500, 2ftlb, running it straight up will give you a gain at 7000 of 30hp in my tests.
Hope that helps.
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Re: At risk of being retarded
[Re: emarine01]
#228584
02/21/09 02:39 PM
02/21/09 02:39 PM
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Joined: Jan 2005
Posts: 1,260
Las Vegas NV
moparmanjames
pro stock
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pro stock
Joined: Jan 2005
Posts: 1,260
Las Vegas NV
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Quote:
Wow , thats going the other way than I was thinking, The older I get seems the less I know, Thanks again for the leg work , what kinda hp & torque numbers were you seeing?
693hp pretty much from 6600 to 7000 and 616 tq at 5100, but my test runs were very specific and I only graphed from 5100 to 7000 so I could focus on your particular needs.
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Re: At risk of being retarded
[Re: moparmanjames]
#228585
02/21/09 02:47 PM
02/21/09 02:47 PM
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Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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I was guessing that he could have used something like a 112 lsa, installed at 104-106 and just a little more duration, something about 286-290... just a guess
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Re: At risk of being retarded
[Re: emarine01]
#228588
02/21/09 03:28 PM
02/21/09 03:28 PM
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Joined: Jan 2005
Posts: 1,260
Las Vegas NV
moparmanjames
pro stock
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pro stock
Joined: Jan 2005
Posts: 1,260
Las Vegas NV
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Quote:
The only program I have is the freebe from cam quest <comp cams> I was getting numbers close to yours , My buddy has desk top dyno and the numbers were 75 hp lower , I allways thought this was around a 600hp engine , we have run with and beaten guys with dyno sheets over 700hp in trucks close to the same weight, I allways thought I was just lucky? 
Well, I did use a 1050 dominator and 2" headers, with the cam you have now I only got 665 or so hp, so you weren't far off with your program.
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Re: At risk of being retarded
[Re: emarine01]
#228590
02/21/09 04:30 PM
02/21/09 04:30 PM
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Joined: Jan 2005
Posts: 1,260
Las Vegas NV
moparmanjames
pro stock
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pro stock
Joined: Jan 2005
Posts: 1,260
Las Vegas NV
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Quote:
With the big cam we run a 1050 on a 2" spacer , small cam we went down to the 850 bg ,the bg guys say that the 850 will flow over 1000 any time any where? You are showing a major gain with your cam choise , a 104lsa just blows me away on how my mind isent grasping the cam timing thing , with a 104 lsa means more overlap , with my fender well headers at a low idle around 1000 rpm the 106lsa will just about suck your shirt off if your close to the header, at 104 lsa I might be sucken down low flying birds, might have to put a screen up or something?
Well I would turn the idle up a bit then lol. Keep in mind that this is going to run about the same at 5500 but it slowly gains on the other cam to 7000. The difference builds to 30 hp @ 7000 rpm.
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Re: At risk of being retarded
[Re: emarine01]
#228592
02/21/09 06:08 PM
02/21/09 06:08 PM
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Joined: Jan 2005
Posts: 1,260
Las Vegas NV
moparmanjames
pro stock
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pro stock
Joined: Jan 2005
Posts: 1,260
Las Vegas NV
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Quote:
Hey I see where your going with the 104, went on cam quest and went with a chebby , comp has lots of cams for chebbys compared to mopars, can play with specs more, the torque is coming from early intake closing with the tight lca and the hp from the long duration in upper rpms?
Yes, that's why I bought this program, to experiment with parts before I bought them and save a boatload of money on parts I would have otherwise had to guess about.
It's around $500 but it's paid for itself over the 6 years that I have had it.
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So straight up off of the cam card could still be 4 degreees advanced 
