Got my cam today...a bit confused!
Thread Starter
Staging Lane
Joined: Jun 2003
Posts: 66
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Got my cam today...a bit confused! 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.
TECH Junkie
Joined: Nov 2001
Posts: 3,604
Likes: 0
From: Los Angeles
Re: Got my cam today...a bit confused! 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?
Re: Got my cam today...a bit confused!
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?
What kind of performance difference would one see between the two lifts mentioned above?
Josh
Re: Got my cam today...a bit confused! 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
TECH Enthusiast
Joined: Nov 2002
Posts: 593
Likes: 1
From: Chicago Heights, IL
Re: Got my cam today...a bit confused! 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! 
