Another YT rocker question
10-06-2003, 08:36 PM
#1
Staging Lane
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Another YT rocker question I did the search and didn't see anything relating to this, though I'm sure there is something somewhere.
Anyhow my question has to do with running YT 1.8 rocker arms with a LS6 cam and 918 springs. First of all will the lift surpass the spring spec? What would be the combined lift of the rockers and cam and care to guesstimate hp/tq numbers gained?
Thanks,
Jocko
Anyhow my question has to do with running YT 1.8 rocker arms with a LS6 cam and 918 springs. First of all will the lift surpass the spring spec? What would be the combined lift of the rockers and cam and care to guesstimate hp/tq numbers gained?
Thanks,
Jocko
10-07-2003, 02:34 AM
#2
Launching!
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Re: Another YT rocker question What year LS6? The 2001 is .525/.525, the 2002 is .551/.547.
In any case, the formula to figure lift when changing rocker ratio is to take the gross valve lift of the cam you plan on using and divide by the stock rocker arm ratio. This will be the cam's lobe lift. Now multiply the lobe lift by the new rocker arm ratio, and the answer will be the new amount of gross valve lift.
For example, using the 2001 cam numbers:
.525 / 1.7 = 0.3088
1.8 * 0.3088 = 0.5559
As the 918 springs are rated to handle roughly a .600 lift, you should be in good shape.
In any case, the formula to figure lift when changing rocker ratio is to take the gross valve lift of the cam you plan on using and divide by the stock rocker arm ratio. This will be the cam's lobe lift. Now multiply the lobe lift by the new rocker arm ratio, and the answer will be the new amount of gross valve lift.
For example, using the 2001 cam numbers:
.525 / 1.7 = 0.3088
1.8 * 0.3088 = 0.5559
As the 918 springs are rated to handle roughly a .600 lift, you should be in good shape.