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Re: cam lobe separation
[Re: D-50]
#1476325
07/31/13 09:14 PM
07/31/13 09:14 PM
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Joined: Jan 2003
Posts: 11,722
Portage,michigan
B3422W5
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Quote:
I just looked at my cam card and it says the lobe separation is 104 int./ 112 ex. How well with that work with NOS ? I would like to spray mine and make a 5.99 or better 1/8 mile pass.
A cam only has one LSA, that is ground when it's made. The LSA is degrees between intake and exhaust centerlines in crank degrees.
Wider kills low end torque and bleeds off effective compression, but makes more high rpm horsepower
69 Dart GTS A4 Silver All steel, flat factory hood, 3360race weight
418 BPE factory replacement headed stroker, 565 lift solid cam
Best so far, 10.40 @127 1/4
1.41 best 60 foot
6.60 at 103.90 1/8
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Re: cam lobe separation
[Re: Sport440]
#1476327
07/31/13 10:58 PM
07/31/13 10:58 PM
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Joined: Jan 2003
Posts: 11,722
Portage,michigan
B3422W5
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Quote:
Quote:
Quote:
I just looked at my cam card and it says the lobe separation is 104 int./ 112 ex. How well with that work with NOS ? I would like to spray mine and make a 5.99 or better 1/8 mile pass.
A cam only has one LSA, that is ground when it's made. The LSA is degrees between intake and exhaust centerlines in crank degrees.
Wider kills low end torque and bleeds off effective compression, but makes more high rpm horsepower [
LSA is in Cam degrees ILC is in Crank degrees. The numbers D50 posted are ILC in crank degrees. His cam has a 108 LSA and is installed 4* advanced giving him those numbers of ILC 
Sorry, I thought he said 104 and 112 a few posts up, which didn't/ doesnt make sense to me when we were talking LSA, which is only 1 number, not two.... Might want to read that post he made I was referencing
69 Dart GTS A4 Silver All steel, flat factory hood, 3360race weight
418 BPE factory replacement headed stroker, 565 lift solid cam
Best so far, 10.40 @127 1/4
1.41 best 60 foot
6.60 at 103.90 1/8
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Re: cam lobe separation
[Re: Al_Alguire]
#1476328
07/31/13 11:24 PM
07/31/13 11:24 PM
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Joined: Jan 2003
Posts: 11,722
Portage,michigan
B3422W5
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Quote:
Funny you say that. My experience with wide LSA cams came from my time playing with Pontiacs, hardly good cylinder head high RPM cars. This was a number of years ago but most of their cams have or had back then wide LSA's. This is what got me to thinking of trying them in a Mopar and we have been very happy with the results.
Narrow lobe center stuff sems to be way peaky to me, or at least what I have had experience with. OH yeah I think most SS stuff is going to have a wide lobe center too.
I have seen the wider LSA's have made more power and gone quicker at the track. SB Fords, Pontiacs Chevys and Mopars. They seem to spread out torque as well so from my experience I will stick with what I have seen work for me. Of course a cam is only ONE part of the equation, to make a car run good numbers it is a combination not a magic part that makes the difference.
I think it is interesting to see what kind of results people get with certain combinations. Also would be interested to see how far they went to see IF there was a gain. Or if it was simply a cam swap and nothing else.
In my case, after Scott brown specced the cam I flogged the car weekly the whole summer trying everything I could think of just to get the car to run like it had with the old cam that itself I didnt consider optimal after leaving it in after a top end swap as I detailed earlier
Initial outing with the new top end and old cam netted a 10.38, in more typical air it ran mid 10.40's
About 6 weeks Into racing season, I made the swap to the112 Scott ground up.
Car ran 60's and low 70's no matter timing, jetting, changing launch technique or shift points.
Finally it got to be late August and I decided to wait till end of season to put either another cam or my old one back in...... That night it ran its best ever lap with that 112, 10.55...... The next pass that night it blew up( broke cast stroker I was stupidly leaning on. That night would have been a 10.40-42 pass with the old cam
Car just was a dog out of the gate with that wide cam, could actually feel it in the seat, didn't need the 60/330 numbers to prove it
69 Dart GTS A4 Silver All steel, flat factory hood, 3360race weight
418 BPE factory replacement headed stroker, 565 lift solid cam
Best so far, 10.40 @127 1/4
1.41 best 60 foot
6.60 at 103.90 1/8
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Re: cam lobe separation
[Re: Al_Alguire]
#1476330
08/01/13 12:49 AM
08/01/13 12:49 AM
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Joined: Jan 2005
Posts: 1,260
Las Vegas NV
moparmanjames
pro stock
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pro stock
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Posts: 1,260
Las Vegas NV
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Quote:
Narrow lobe center stuff sems to be way peaky to me, or at least what I have had experience with. OH yeah I think most SS stuff is going to have a wide lobe center too.
I have seen the wider LSA's have made more power and gone quicker at the track.
You are correct, a narrow lobe separation angle will make more peak torque in a narrower power range. A wide lobe separation angle flattens and broadens the curve.
Think of a narrow LSA representing a narrow peak and a wide LSA representing a longer mesa type peak.
The narrow LSA will give you a much higher number at a lower rpm, but the wide LSA will give you a higher number in the higher rpms and is easier to hook up because of less peak torque.
General Motors used this wide LSA/higher compression formula when building their corvette to get good mileage without sacrificing much performance.
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Re: cam lobe separation
[Re: Mopar-Al]
#1476331
08/01/13 12:50 AM
08/01/13 12:50 AM
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Joined: Jan 2003
Posts: 11,722
Portage,michigan
B3422W5
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Quote:
I run a 113 lobe seperation installed at 113 center. I launch around 6k or a bit more and shift at 8400, I am running B1 originals on a 511. I have around 13.8 comp. The car just flatazz pulls on the top end and is deadly consistant. My combo seems to work as expected for me.
Yep, perfect application for a wide LSA cam, lots of compression and RPM, good heads, and no need for low RPM torque as evidenced by your launch rpm. Exactly the ingredients one would need to make a wide LSA work/ shine N/A.
Kinda helps make the point.
69 Dart GTS A4 Silver All steel, flat factory hood, 3360race weight
418 BPE factory replacement headed stroker, 565 lift solid cam
Best so far, 10.40 @127 1/4
1.41 best 60 foot
6.60 at 103.90 1/8
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Re: cam lobe separation
[Re: B3422W5]
#1476332
08/01/13 01:25 AM
08/01/13 01:25 AM
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Joined: Jan 2003
Posts: 6,591
Canton, Ohio
Sport440
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master
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Canton, Ohio
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Quote:
Quote:
Quote:
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I just looked at my cam card and it says the lobe separation is 104 int./ 112 ex. How well with that work with NOS ? I would like to spray mine and make a 5.99 or better 1/8 mile pass.
A cam only has one LSA, that is ground when it's made. The LSA is degrees between intake and exhaust centerlines in crank degrees.
Wider kills low end torque and bleeds off effective compression, but makes more high rpm horsepower [
LSA is in Cam degrees ILC is in Crank degrees. The numbers D50 posted are ILC in crank degrees. His cam has a 108 LSA and is installed 4* advanced giving him those numbers of ILC
Sorry, I thought he said 104 and 112 a few posts up, which didn't/ doesnt make sense to me when we were talking LSA, which is only 1 number, not two.... Might want to read that post he made I was referencing
Don, I read it just fine. I was correcting both you and him. One and Two 
He did state two numbers as you stated incorrectly as LSA numbers 104 and 112. 
"Correction" They are actually Lobe centerline numbers measured in Crank degrees.
You stated that LSA numbers were measured in Crank degrees.
"Correction" LSA numbers are measured in Cam degrees.
I just dont want to confuse people, I know you know your stuff, even I miss typed stuff myself. 
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Re: cam lobe separation
[Re: Sport440]
#1476333
08/01/13 02:26 AM
08/01/13 02:26 AM
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Joined: Jan 2003
Posts: 11,722
Portage,michigan
B3422W5
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LSA ( lobe separation angle) is in fact measured in crank degrees,I have said twice now it is a fact it is measured in crankshaft degrees between the e xhaust and intake centerlines...... That spread in CRANKSHAFT degrees is the LSA, can't explain it any clearer 
Last edited by B3422W5; 08/01/13 02:34 AM.
69 Dart GTS A4 Silver All steel, flat factory hood, 3360race weight
418 BPE factory replacement headed stroker, 565 lift solid cam
Best so far, 10.40 @127 1/4
1.41 best 60 foot
6.60 at 103.90 1/8
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Re: cam lobe separation
[Re: B3422W5]
#1476335
08/01/13 09:37 AM
08/01/13 09:37 AM
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Joined: Jan 2003
Posts: 13,376
Marion, South Carolina [><]
an8sec70cuda
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Quote:
Quote:
I run a 113 lobe seperation installed at 113 center. I launch around 6k or a bit more and shift at 8400, I am running B1 originals on a 511. I have around 13.8 comp. The car just flatazz pulls on the top end and is deadly consistant. My combo seems to work as expected for me.
Yep, perfect application for a wide LSA cam, lots of compression and RPM, good heads, and no need for low RPM torque as evidenced by your launch rpm. Exactly the ingredients one would need to make a wide LSA work/ shine N/A.
Kinda helps make the point.
 with B3422W5...been there, done that, wasted money.
CHIP
'70 hemicuda, 575" Hemi, 727, Dana 60
'69 road runner, 440-6, 18 spline 4 speed, Dana 60
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'73 Chrysler New Yorker, 440, 727, 8.75
'90 Chevy 454SS Silverado, 476" BBC, TH400, 14 bolt
'06 GMC 2500HD LBZ Duramax
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Re: cam lobe separation
[Re: B3422W5]
#1476336
08/01/13 10:15 AM
08/01/13 10:15 AM
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Joined: Jan 2003
Posts: 6,591
Canton, Ohio
Sport440
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When a Cam comp. states a cams Lobe Seperation Angle as in 108 , 110 , or 112, they are indeed referencing a Lobe seperation in CAM degrees IN D50,s case he states Two numbers add those up! They will equal 216 CRANK degrees. So is his cam a 216 LSA, because in Crank degrees those lobes are indeed 216* apart Or 108* apart in Cam degrees. The crank turns twice for every one revolution of the cam. Lobe seperation angle is Cam degrees. Installed Intake centerline is Crank degrees. The Math doesnt lie, it either is or isnt.
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Re: cam lobe separation
[Re: MR_P_BODY]
#1476339
08/01/13 04:08 PM
08/01/13 04:08 PM
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Joined: Jan 2003
Posts: 6,591
Canton, Ohio
Sport440
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Quote:
Quote:
When a Cam comp. states a cams Lobe Seperation Angle as in 108 , 110 , or 112, they are indeed referencing a Lobe seperation in CAM degrees
IN D50,s case he states Two numbers add those up! They will equal 216 CRANK degrees. So is his cam a 216 LSA, because in Crank degrees those lobes are indeed 216* apart
Or 108* apart in Cam degrees. The crank turns twice for every one revolution of the cam.
Lobe seperation angle is Cam degrees.
Installed Intake centerline is Crank degrees.
The Math doesnt lie, it either is or isnt.
Look at the graph I just posted... does it look like
the lobes are greater than 180* apart
EDIT
The cam LSA is indeed measured on the cam itself
but in the above you add the 2 together then divide
by 2 to find the average(108 in this case)
Yep, Indeed Everyone who listed thier LSA whether it was 107 to 117 was in Cam degreees.
You could list it in Crank degrees too, but nobody did. If they did the numbers would be 214 to 234 
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Re: cam lobe separation
[Re: Sport440]
#1476340
08/01/13 04:23 PM
08/01/13 04:23 PM
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Posts: 11,722
Portage,michigan
B3422W5
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Sport 440.....said "Lobe seperation angle is cam degrees" From Car Tech, by Mike Petralia "Lobe Separation Angle (LSA) is NOT the same as Lobe Centerlines (LC), although the two are directly connected. The Lobe Separation Angle is measured as the degrees that the CRANKSHAFT rotates BETWEEN the exhaust valve’s maximum lift point (aka: Exhaust Centerline) and the intake valve’s maximum lift point (aka: Intake Centerline). Check the lead illustration in this story from COMP Cams to show this effect. The highest lift points on the lobes are referred to as the cam “Lobe Centerlines” and are usually ground somewhere between 102 and 122 CRANKSHAFT degrees. Since Lobe Centerline is referenced in relation to crankshaft degrees as well, it can be moved around, depending on where you install the cam." Hope this puts this to bed  
Last edited by B3422W5; 08/01/13 04:25 PM.
69 Dart GTS A4 Silver All steel, flat factory hood, 3360race weight
418 BPE factory replacement headed stroker, 565 lift solid cam
Best so far, 10.40 @127 1/4
1.41 best 60 foot
6.60 at 103.90 1/8
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Re: cam lobe separation
[Re: B3422W5]
#1476341
08/01/13 05:35 PM
08/01/13 05:35 PM
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Joined: Jan 2003
Posts: 6,591
Canton, Ohio
Sport440
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Don, Im glad your smiling this time. Last time you were yelling at me, I heard you. Sport 440 Said " Lobe Seperation Angle is in Cam Degrees" Yep, I said that alright. And this wont be put to bed until I hear you Agree In thats Mike P,s text it has an Error. He used the word Crank when it should of been Cam in reguards to LSA. LSA Can be measured in Cam or Crank degrees But the Numbers that everybody states including you, me, the others, and All the Cam companies for LSA are in Cam degrees. If you see a 110 LSA Comp cam advertised, that number is in Cam degrees. If its advertised in Crank degrees as Mike P states, it would be a 220 LSA cam. They would have the Same exact LSA, just measured two different ways. That text your reading from Mike Petralia is wrong in that one word error crank vs cam. Now Lobe Centers are indeed measured in Crank degrees. A 110 LSA cam installed straight up or Dead center between its two peak lobe lifts will be at 55* at the cam rotate it 55* ATDC and the crank moves 110* Rotate it BTDC 55* and the crank moves 110* Both intake and exhaust Lobe centers are at 110* dead center or straight up as I call it. The total distance between the two 220 Crank degrees or 110 Cam degrees,. Tell me How can Mikes Petralia text still be right. Not a phone text ,just the text your reading. Hang with me on this LSA, LC, can be confusing at times, and for alot of people, even me at one time. But, I got a handle on this, there is no doubt, not a shadow, from what Im telling you. Dont listen to Mike Petralias single word Misprint. Its misleading you. Listen to Sport 440, or Mike F/ me Further read the above and think about it and Listen to your own mind. We will be on the Same page, I guarantee it.
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Re: cam lobe separation
[Re: Sport440]
#1476342
08/01/13 06:31 PM
08/01/13 06:31 PM
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Joined: Jan 2003
Posts: 11,722
Portage,michigan
B3422W5
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Actually, when we were argueing last night, i was at home and using my phone for internet......i did a search and found that article i quoted right at the top of the search... after reading it and seeing it for what it was( incorrect) i figured i would try you on and post it..... It didnt work...lol
69 Dart GTS A4 Silver All steel, flat factory hood, 3360race weight
418 BPE factory replacement headed stroker, 565 lift solid cam
Best so far, 10.40 @127 1/4
1.41 best 60 foot
6.60 at 103.90 1/8
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All the specs.I have seen on a cam card are in reference to crankshaft degrees, I think 
