Question regarding Lobe sep/Intake centerline?
Thread Starter
Joined: Nov 2001
Posts: 7,303
Likes: 4
From: Delray Beach, Fl.
Question regarding Lobe sep/Intake centerline? Say u have a cam with a 113LSA and it has no advance ground into it so its in at 113ICL if u put it in straight up?
How would this cam compare HP/TQ wise to the same cam with 4 degree;s of advance ground into it?
Anyone?
JS
How would this cam compare HP/TQ wise to the same cam with 4 degree;s of advance ground into it?
Anyone?
JS
TECH Addict
Joined: Dec 2001
Posts: 2,298
Likes: 2
From: new england
Re: Question regarding Lobe sep/Intake centerline? This is not a simple question/ answer, your cams duration and motors compression decide how critical your ICL is.Your heads flow characteristics also affect ultimate setting.The trend in my experience is small duration cams dont like much advance in mild engines.The peakier your head flow is the more advance you would want to run also.Long intake runners and full exhaust are why LS1 likes relatively wide LSA's and min. cam advance.If you have plenty of cylinder pressure and compression, then small to medium sized cams will make most power with 2* advance ground in allowing for late enough intake valve closure.These are trends not rules but i believe i am right about most of this .
Thread Starter
Joined: Nov 2001
Posts: 7,303
Likes: 4
From: Delray Beach, Fl.
Re: Question regarding Lobe sep/Intake centerline? But now it gets even more complicated.
Suppose u never checked to see if the cam is in where its supposed to be and have a STOCK chain that has normal factory slop in it.
Most camshaft companies are adding at least 2 degree's into there camshafts on the LS1 for that reason.
So its possible it could be in 2 or maybe even 4 degree's retarded using a stock timing set?
I think this is absolutley possible....
JS
<small>[ September 10, 2002, 07:45 AM: Message edited by: JS ]</small>
Suppose u never checked to see if the cam is in where its supposed to be and have a STOCK chain that has normal factory slop in it.
Most camshaft companies are adding at least 2 degree's into there camshafts on the LS1 for that reason.
So its possible it could be in 2 or maybe even 4 degree's retarded using a stock timing set?
I think this is absolutley possible....
JS
<small>[ September 10, 2002, 07:45 AM: Message edited by: JS ]</small>
Thread Starter
Joined: Nov 2001
Posts: 7,303
Likes: 4
From: Delray Beach, Fl.
Re: Question regarding Lobe sep/Intake centerline? Would like an answer to my last question from the camshaft guru's....
Chirs B,Raugh,Fireball,PatrickG,JmX ???
Anyone?
JS
Chirs B,Raugh,Fireball,PatrickG,JmX ???
Anyone?
JS
TECH Addict
Joined: Dec 2001
Posts: 2,298
Likes: 2
From: new england
Re: Question regarding Lobe sep/Intake centerline? You are right that most cams have 2* advance ground in, some have as much as 4*, so cam wont end up retarded, maybe straight up .Cam would have to be ground with no advance to be retarded that much with chain stretch.
Thread Starter
Joined: Nov 2001
Posts: 7,303
Likes: 4
From: Delray Beach, Fl.
Re: Question regarding Lobe sep/Intake centerline? Nothing Big,More or less I'm trying to get some info regarding cam timing and its effect on ET/MPH....
JS
JS
Trending Topics
TECH Fanatic
Joined: Aug 2002
Posts: 1,566
Likes: 0
From: Objects in mirror no longer matter.
Re: Question regarding Lobe sep/Intake centerline? </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by JS:
<strong>Nothing Big,More or less I'm trying to get some info regarding cam timing and its effect on ET/MPH....
JS</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">JS, judging from your numbers I really doubt that your cam is degreed incorrectly. Where did your horsepower peak?
<strong>Nothing Big,More or less I'm trying to get some info regarding cam timing and its effect on ET/MPH....
JS</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">JS, judging from your numbers I really doubt that your cam is degreed incorrectly. Where did your horsepower peak?
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?
Pouria Savadkouei
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine
Verdad Gallardo
7 Most Reliable High-Performance Engines GM Has Ever Built
Verdad Gallardo
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin
Verdad Gallardo
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo Thread Starter
Joined: Nov 2001
Posts: 7,303
Likes: 4
From: Delray Beach, Fl.
Re: Question regarding Lobe sep/Intake centerline? Chris,I'm doing a Katech pump/IRL chain in 2 weeks,I figured since I'm adding these parts I might as well check the cam timing too.
Surely u wouldnt think this isnt a smart idea since your already in the motor?
JS
Surely u wouldnt think this isnt a smart idea since your already in the motor?
JS
Teching In
Joined: Nov 2001
Posts: 28
Likes: 0
From: DFW
Re: Question regarding Lobe sep/Intake centerline? Here's some numbers from a Comp Cam test.
This is and old school 350 with the only difference being the cam position.
Even though it's not a LS1, it shows what changes you can expect by moving a cam around.
Avg. through 4000 RPM
4* adv. - 0* - 4* ret.
TQ 379.4 - 373.2 - 369.0
HP 220.4 - 218.2 - 213.7
Avg. 4200 to 6250
TQ 369.4 - 371.4 - 371.4
HP 365.9 - 368.2 - 368.4
Average overall
TQ 374.4 - 373.2 - 369.0
HP 293.2 - 293.2 - 291.1
<small>[ September 12, 2002, 06:06 AM: Message edited by: Shaner ]</small>
This is and old school 350 with the only difference being the cam position.
Even though it's not a LS1, it shows what changes you can expect by moving a cam around.
Avg. through 4000 RPM
4* adv. - 0* - 4* ret.
TQ 379.4 - 373.2 - 369.0
HP 220.4 - 218.2 - 213.7
Avg. 4200 to 6250
TQ 369.4 - 371.4 - 371.4
HP 365.9 - 368.2 - 368.4
Average overall
TQ 374.4 - 373.2 - 369.0
HP 293.2 - 293.2 - 291.1
<small>[ September 12, 2002, 06:06 AM: Message edited by: Shaner ]</small>
TECH Senior Member
Joined: Nov 2001
Posts: 10,341
Likes: 1
Re: Question regarding Lobe sep/Intake centerline? You will have to redegree the cam when you swap the chain etc anyways. I would a cam swap while you are in there and try a 230/236 112LSA like Bike Mike is running.
Chris
Chris
Thread Starter
Joined: Nov 2001
Posts: 7,303
Likes: 4
From: Delray Beach, Fl.
Re: Question regarding Lobe sep/Intake centerline? I'm not going into details about my cam timing until I check it frist.But I know the Comp chain thats in my car is the regualar one that uses the STOCK GM chain.
I have a better "IRL chain"/KATECH oil pump sitting here at my shop an I figured since I'll have the car apart I might as well check the cam timing..
JS
<small>[ September 11, 2002, 12:11 PM: Message edited by: JS ]</small>
I have a better "IRL chain"/KATECH oil pump sitting here at my shop an I figured since I'll have the car apart I might as well check the cam timing..
JS
<small>[ September 11, 2002, 12:11 PM: Message edited by: JS ]</small>
TECH Senior Member
Joined: Nov 2001
Posts: 10,341
Likes: 1
Re: Question regarding Lobe sep/Intake centerline? </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by JS:
<strong>I'm not going into details about my cam timing until I check it frist.But I know the Comp chain thats in my car is the regualar one that uses the STOCK GM chain.
I have a better "IRL chain"/KATECH oil pump sitting here at my shop an I figured since I'll have the car apart I might as well check the cam timing..
JS</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Why will you have the engine apart? From your dyno numbers I doubt the cam/chain is screwed up
Chris
<strong>I'm not going into details about my cam timing until I check it frist.But I know the Comp chain thats in my car is the regualar one that uses the STOCK GM chain.
I have a better "IRL chain"/KATECH oil pump sitting here at my shop an I figured since I'll have the car apart I might as well check the cam timing..
JS</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Why will you have the engine apart? From your dyno numbers I doubt the cam/chain is screwed up
Chris
Re: Question regarding Lobe sep/Intake centerline? </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by JS:
<strong>Say u have a cam with a 113LSA and it has no advance ground into it so its in at 113ICL if u put it in straight up?
How would this cam compare HP/TQ wise to the same cam with 4 degree;s of advance ground into it?
Anyone?
JS</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Theoretically the cam should make the engine have more low end. Advancing the cam most of the time will cause the low rpms to gain power while taking it away from the upper rpm. One reason the LS1 has good low end grunt and high end HP along with emmissions is that we have a small duration cam with alot of lift (for stock) and cams that are put in retarded. Retarding a cam does the opposite of a advanced cam. The other thing is if you advance the cam and you gain high end hp it means you have to much duration.
That's a simple look at it.
Bret
<strong>Say u have a cam with a 113LSA and it has no advance ground into it so its in at 113ICL if u put it in straight up?
How would this cam compare HP/TQ wise to the same cam with 4 degree;s of advance ground into it?
Anyone?
JS</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Theoretically the cam should make the engine have more low end. Advancing the cam most of the time will cause the low rpms to gain power while taking it away from the upper rpm. One reason the LS1 has good low end grunt and high end HP along with emmissions is that we have a small duration cam with alot of lift (for stock) and cams that are put in retarded. Retarding a cam does the opposite of a advanced cam. The other thing is if you advance the cam and you gain high end hp it means you have to much duration.
That's a simple look at it.
Bret
Re: Question regarding Lobe sep/Intake centerline? </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Shaner:
<strong>Here's some numbers from a Comp Cam test.
This is and old scool 350 with the only difference being the cam position.
Even though it's not a LS1, it shows what changes you can expect by moving a cam around.
Avg. through 4000 RPM
4* adv. - 0* - 4* ret.
TQ 379.4 - 373.2 - 369.0
HP 220.4 - 218.2 - 213.7
Avg. 4200 to 6250
TQ 369.4 - 371.4 - 371.4
HP 365.9 - 368.2 - 368.4
Average overall
TQ 374.4 - 373.2 - 369.0
HP 293.2 - 293.2 - 291.1</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Shaner that would make sense to what I said above.
Good post.
<strong>Here's some numbers from a Comp Cam test.
This is and old scool 350 with the only difference being the cam position.
Even though it's not a LS1, it shows what changes you can expect by moving a cam around.
Avg. through 4000 RPM
4* adv. - 0* - 4* ret.
TQ 379.4 - 373.2 - 369.0
HP 220.4 - 218.2 - 213.7
Avg. 4200 to 6250
TQ 369.4 - 371.4 - 371.4
HP 365.9 - 368.2 - 368.4
Average overall
TQ 374.4 - 373.2 - 369.0
HP 293.2 - 293.2 - 291.1</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Shaner that would make sense to what I said above.
Good post.
