Got my cam today...a bit confused!
#1
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
I ordered my cam from TSP, but its a custom comp ground cam.
The specs I wanted were 230/224 .575/.563 111LSA
On my cam card, this is what it says
(typed out) Gross Valve lift .588/.584 but written in PEN it says "with a 1.75:1 rocker"
What does that mean, I'm confused, any help would be FANTASTIC! TIA
Btw, everything else is correct.
The specs I wanted were 230/224 .575/.563 111LSA
On my cam card, this is what it says
(typed out) Gross Valve lift .588/.584 but written in PEN it says "with a 1.75:1 rocker"
What does that mean, I'm confused, any help would be FANTASTIC! TIA
Btw, everything else is correct.
![Happy](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_stretch.gif)
#2
TECH Junkie
Join Date: Nov 2001
Location: Los Angeles
Posts: 3,604
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
well, your cam actually only has like .340" of lift, however, the rocker arms "multiply" the lift and that is how you get "valve lift", which is quoted on the cam card.
So, if they were speccing it out with 1.75 rockers, the lift numbers will read higher.
What's all this mean to you?
Well, .588/.584 divided by 1.75 rockers is a cam with .336/.334 lobe lift. Now, stock LS1 rocker ratio is right around 1.7:1, so, multiply those 2 numbers by 1.7 and you get .571/.567 which is pretty close to the .575/.563 numbers you ordered.
Does that make sense?
So, if they were speccing it out with 1.75 rockers, the lift numbers will read higher.
What's all this mean to you?
Well, .588/.584 divided by 1.75 rockers is a cam with .336/.334 lobe lift. Now, stock LS1 rocker ratio is right around 1.7:1, so, multiply those 2 numbers by 1.7 and you get .571/.567 which is pretty close to the .575/.563 numbers you ordered.
Does that make sense?
#5
TECH Fanatic
iTrader: (9)
Join Date: Feb 2002
Location: West Lafayette, IN
Posts: 1,061
Likes: 0
Received 0 Likes
on
0 Posts
![](https://ls1tech.com/forums/images/ranks/ls1tech10year.png)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
well, your cam actually only has like .340" of lift, however, the rocker arms "multiply" the lift and that is how you get "valve lift", which is quoted on the cam card.
So, if they were speccing it out with 1.75 rockers, the lift numbers will read higher.
What's all this mean to you?
Well, .588/.584 divided by 1.75 rockers is a cam with .336/.334 lobe lift. Now, stock LS1 rocker ratio is right around 1.7:1, so, multiply those 2 numbers by 1.7 and you get .571/.567 which is pretty close to the .575/.563 numbers you ordered.
Does that make sense?
So, if they were speccing it out with 1.75 rockers, the lift numbers will read higher.
What's all this mean to you?
Well, .588/.584 divided by 1.75 rockers is a cam with .336/.334 lobe lift. Now, stock LS1 rocker ratio is right around 1.7:1, so, multiply those 2 numbers by 1.7 and you get .571/.567 which is pretty close to the .575/.563 numbers you ordered.
Does that make sense?
![Happy](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_stretch.gif)
What kind of performance difference would one see between the two lifts mentioned above?
Josh
#6
TECH Enthusiast
iTrader: (3)
Join Date: Jun 2002
Location: Georgetown, Texas
Posts: 598
Likes: 0
Received 0 Likes
on
0 Posts
![](https://ls1tech.com/forums/images/ranks/ls1tech10year.png)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
SDPC sells 1.7, 1.75, and 1.8 rockers for our vehicles. They are shaft mount rockers as well...really nice pieces. Check them out here:
http://www.sdpc2000.com/cart.asp?act...amp;catid=3082
http://www.sdpc2000.com/cart.asp?act...amp;catid=3082
#7
TECH Enthusiast
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Nice! I just might have to invest in those for my next mod! I havent had any needle bearing failures yet, but with 68k miles and over 400 RWHP, I don't want to start!
![Grin](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_grin.gif)