whitesilvy04

okay, so i'm trying to do my math here...

Texas-speed 220/220 .581/.581 lift 112LSA with Harland sharp 1.8 ratio Rocker Arms...

Would push my new lift in the cam to a 220/220 .613/.613 lift right??

TurboGibbs

iTrader: (6)

I came up with .6157" lift but who's counting hairs?

Phantom

iTrader: (16)

they recommend not to use higher ratio rockers with that cam...

whitt1

I get .6152,but it's doable with the right valve springs I've run .6156 lift with no issues.

tarinitup

iTrader: (11)

Same thing I got Make sure you check the ramp rate on the cam I was told certain cams shouldn't use 1.8 rockers.

whitesilvy04

yeah, i'm going to run patriot gold springs... good for .650 lift


I'm going to call a few shops and get there opinion on what i'm wanting to do as far as my valvetrain and cam go. Thanks Guys!

99Silverado5.3

iTrader: (7)

If the ramp rate is too high it will beat down on those rockers and throw the harmonics of the engine off.

Why not just get a custom grind cam though to avoid this possible problem?

99Silverado5.3

iTrader: (7)

Hey, not knocking any shops, but most shops don't know wtf they are talking about, unless it is a reputable one...or one you see sponsered on ls1tech or this site.

Just don't base your decison solely on their reccomendation, you will more than likely be dissappointed (performance and wallet).

TurboGibbs

iTrader: (6)

Agreed, there are few shops that have much experience with gen3/4 stuff. They are MUCH different in how to pick cam and compression etc than an old SBC. Technology with the head flow and combustion chamber design allows smaller duration cams to build the same or more power and more compression with pump gas than your conventional SBC.
And things such as .550" lift with a SBC is A LOT of lift for a reliable street engine unless you have some high dollar long stem valves, springs, pushrods etc. .550" lift on a gen3 is achievable with stock parts(accept maybe springs).

RandomHero

iTrader: (24)

do a before and after dyno. This would probably answer a lot of questions on the stock 5.3L heads.