What makes a cam "lope?"
Teching In
Joined: Nov 2004
Posts: 9
Likes: 0
From: Lafayette,Indiana
Originally Posted by Beast96Z
The amount of overlap is what causes your "rough idle". You can figure this with this equation: Intake duration + Exaust duration, divided by 4, - LSA, x 2. The more overlap, the rougher the idle. For the cams listed you have 5 degrees for the 230/224, 25 for the T-rex, and 11 for the ASA.
Now that I have read the whole conversation, I have not seen the "range" on where a "stock idle" would stop to where a mild lump would start and where a heavy lump starts. I see several results for the math as a negtive number and this means good idle and pass the sniffer test, right??? The three cams have the different postive numbers and the range from 5 to11. Now you all agree the 5 will be better that the 11 but, would these numbers fall in the "no lump" range or possability in the "mild lump" range.
While I am far from a expert on this subject, I would hardly call an ASA a "mild lump" cam. I knew someone with an ASA in a 00' SS and it sounded mean. If I had to guess I would say a "mild lump" cam would fall in the low negative numbers.
11 Second Club
Joined: Feb 2003
Posts: 5,524
Likes: 1
From: The South
Originally Posted by 02SS0384
While I am far from a expert on this subject, I would hardly call an ASA a "mild lump" cam. I knew someone with an ASA in a 00' SS and it sounded mean. If I had to guess I would say a "mild lump" cam would fall in the low negative numbers.
Teching In
Joined: Nov 2004
Posts: 9
Likes: 0
From: Lafayette,Indiana
HUMMM interesting.........
After reading this I went and got the cam card that I am installing for a customer,( Car is stock except for a set of LPE heads and LTH and now this cam.) I will be doing the software work afterwards and it will be interesting the outcome on the predition of the cam chosen. It is the GM LS1 hotcam 525/525 218/227 112 and after doing the math I came up with -1.5 Since you all agree that a low negtive number will creat a mild lump. When I complete the work (also reworking the trans to handel estimated 500RWHP)I will post the results of the "Math" vs reality
After reading this I went and got the cam card that I am installing for a customer,( Car is stock except for a set of LPE heads and LTH and now this cam.) I will be doing the software work afterwards and it will be interesting the outcome on the predition of the cam chosen. It is the GM LS1 hotcam 525/525 218/227 112 and after doing the math I came up with -1.5 Since you all agree that a low negtive number will creat a mild lump. When I complete the work (also reworking the trans to handel estimated 500RWHP)I will post the results of the "Math" vs reality
I know this may be a little off topic, but here's my dilemma....
I am installing a TSP 233/239 in my Stock C.i. 346.....
Overlap-12*
split-6*
Will this "lope" harder/softer, or indifferent than the current cam setup in my father's Big Block? Its a 468c.i.
Overlap-19*
split-6*
What I'm wondering is does C.i. affect "lope" as well.....I mean, wouldn't it have to? I came up with the 19* of overlap on my father's cam using the same calculation I used for overlap on my cam(I+E, /4, -LSA, x2)
Do all the same rules apply? I say there's no way they could....can someone elaborate a little on this for me??
I am installing a TSP 233/239 in my Stock C.i. 346.....
Overlap-12*
split-6*
Will this "lope" harder/softer, or indifferent than the current cam setup in my father's Big Block? Its a 468c.i.
Overlap-19*
split-6*
What I'm wondering is does C.i. affect "lope" as well.....I mean, wouldn't it have to? I came up with the 19* of overlap on my father's cam using the same calculation I used for overlap on my cam(I+E, /4, -LSA, x2)
Do all the same rules apply? I say there's no way they could....can someone elaborate a little on this for me??
11 Second Club
Joined: Feb 2003
Posts: 5,524
Likes: 1
From: The South
Originally Posted by cadmaster
HUMMM interesting.........
After reading this I went and got the cam card that I am installing for a customer,( Car is stock except for a set of LPE heads and LTH and now this cam.) I will be doing the software work afterwards and it will be interesting the outcome on the predition of the cam chosen. It is the GM LS1 hotcam 525/525 218/227 112 and after doing the math I came up with -1.5 Since you all agree that a low negtive number will creat a mild lump. When I complete the work (also reworking the trans to handel estimated 500RWHP)I will post the results of the "Math" vs reality
After reading this I went and got the cam card that I am installing for a customer,( Car is stock except for a set of LPE heads and LTH and now this cam.) I will be doing the software work afterwards and it will be interesting the outcome on the predition of the cam chosen. It is the GM LS1 hotcam 525/525 218/227 112 and after doing the math I came up with -1.5 Since you all agree that a low negtive number will creat a mild lump. When I complete the work (also reworking the trans to handel estimated 500RWHP)I will post the results of the "Math" vs reality
Teching In
Joined: Nov 2004
Posts: 9
Likes: 0
From: Lafayette,Indiana
My Bag!!
The bottom end is the only thing stock. It has more goodies, (that are not base engine mechanical, what I met “stock” in the early post, I was refering to the engine internals) and going to have more goodie in the future but since I pulled the engine to repair a massive oil consumption problem (got to love the UAW for the high dollar there people get but the quality of work is crap!!!! 4 pistons had all the gaps lined up). He wanted me to go through it to so when more parts are added on to increase HP the trans will hold it. I finished the transmission yesterday and it will be rock solid to 500RWHP after that ........................AXLE problems?????????
The bottom end is the only thing stock. It has more goodies, (that are not base engine mechanical, what I met “stock” in the early post, I was refering to the engine internals) and going to have more goodie in the future but since I pulled the engine to repair a massive oil consumption problem (got to love the UAW for the high dollar there people get but the quality of work is crap!!!! 4 pistons had all the gaps lined up). He wanted me to go through it to so when more parts are added on to increase HP the trans will hold it. I finished the transmission yesterday and it will be rock solid to 500RWHP after that ........................AXLE problems?????????
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
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
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
Five Reasons the Camaro Was the Most Pivotal Player in the Pony Car Wars 2.0
Brett Foote
11 Second Club
Joined: Feb 2003
Posts: 5,524
Likes: 1
From: The South
Originally Posted by SSick
in my garage is an F10 it's gunna have a stock idle? 228 + 228 /4 - 114 x2 = 0 overlap?
who else has an F10 on 114?
who else has an F10 on 114?
Ok I'm cofused I just installed a 244/250 .615/.615 116+4 in my car and it sounds like a TR220 or 224 
I thought the overlap was supposed to be around 19 or so. What the hell happened 
I thought the overlap was supposed to be around 19 or so. What the hell happened Last edited by BAIN; Feb 10, 2005 at 02:24 PM.
Overlap should be 11(if you include your +4)
and split is 6...
Sounds like you're either idling really high, or you got a lot of timing in the car...either of these true? It should idle VERY similiar to a TSP 233/239
and split is 6...
Sounds like you're either idling really high, or you got a lot of timing in the car...either of these true? It should idle VERY similiar to a TSP 233/239
Registered User
Joined: Jun 2007
Posts: 2
Likes: 0
I have been reading this thread with great interest - I just built a stroker motor that is 526 ci - my cam "number" is 74 - but the engine does not lope at all.Idles at a grand, but little lope. My last motor with 454 ci and a cam that calculates (using the above calc) to a 66 and loped like a pro stocker, so there has to be a relashionship between cubic inches and the lope. I first put in a cam that was a 70 - and it sounded like a UPS truck. New cam is a 74, better but not where I want it. Any thoughts or guidelines on how to make my stroker sound like my "little" motor did for the car cruises? BTW - these are both solid roller cams ground on a 108 LC and just shy of .700 lift. Do I need a new cam with huge overlap number (what number???) or can I roughen mine up somehow?
(I'm at 286 deg duration @ .050)...
(I'm at 286 deg duration @ .050)...
Last edited by Brnasi; Jun 10, 2007 at 07:58 PM.
Banned
Joined: Apr 2006
Posts: 1,875
Likes: 1
From: Naperville, IL
Originally Posted by Brnasi
I have been reading this thread with great interest - I just built a stroker motor that is 526 ci - my cam "number" is 74 - but the engine does not lope at all.Idles at a grand, but little lope. My last motor with 454 ci and a cam that calculates (using the above calc) to a 66 and loped like a pro stocker, so there has to be a relashionship between cubic inches and the lope. I first put in a cam that was a 70 - and it sounded like a UPS truck. New cam is a 74, better but not where I want it. Any thoughts or guidelines on how to make my stroker sound like my "little" motor did for the car cruises? BTW - these are both solid roller cams ground on a 108 LC and just shy of .700 lift. Do I need a new cam with huge overlap number (what number???) or can I roughen mine up somehow?
(I'm at 286 deg duration @ .050)...
(I'm at 286 deg duration @ .050)...
Registered User
Joined: Jun 2007
Posts: 2
Likes: 0
Originally Posted by Asmodeus
lower the idle for more lope. even with a lot of overlap you can get rid of lope with a higher idle. You'll create more exhaust velocity to pull the intake charge out of the cylinder causing less of the "choking onit's own exhaust" as Eric put it. exact opposite effect with lowering the idle. you'll have even less exhaust scavenging.
Thanks, I tried that today, at 900 RPM it just dies. I am thinking it may be partially the effect of the idle speed on the sound - a bad (good) lope (gallop) at 1200 RPM sounds much different than one at 900-1000 RPM (Loaded). At 1200 RPM on the new motor it's pretty smooth.
Maybe the exhaust is too small in diameter now (3.5) or the ratio of over lap to cubes isn't there...My other big block with a mild hyd lopes better than this. It also has flowmasters on it, vs my Dynomax's on the stroker motor - so the stroker is actually pretty quiet.