what is the difference between the different sizes of RR's. what benefits do they give you so on?

 

Whatengine do you have? The LSx motors use 1.7 ratio stock. The Ratio refers to the amount the cam lobe lift is multiplied. If your using 1.5 ratio rockers and the lift at the cam lobe is .300 then the valve lift will be .450 (.300X1.5=.450).

Re'

 

Ditto what Re said.

The benefits are increased valve lift = more power.

When talking about rockers in general on most SBC engines (Gen I and Gen II), the lift specs on a camshaft are at lobe lift and advertised at 1.5:1. The way to calculate lift on aftermarket and higher-ratio rockers is simply divide by the rocker ratio to get the lobe lift, then multiply times the new ratio.

The drawbacks on putting larger-than-stock rockers on the LS1 engines is that nearly all of the performance camshafts have lots of lift already ground into them (most performance cams are well over .560 lift with 1.7:1 rockers) and you'll run into piston to valve clearance problems if you install an aftermarket camshaft in the future. The stock rockers are great for nearly any buildup. If you need a serious valvetrain for lots of duration, lift, or solid roller, the only worthwhile upgrade IMO would be going to a $800-1000 shaft mount setup.

Mike

 

The other draw back is that for the price of aftermarket 1.8 rockers you can get a cam grind of your choice and supporting mods (springs, LS2 chain etc).

 

oh ok i understand now thanks guys. um... i have the lt1, but wanting upgrade to bigger RR's. what would be of choice? the cam has close to .500/.500 lift with stock RR. i also have lunati valve springs to go on them, so would this make it easier to upgrade to higher RR ratios? i was thinking 1.6 or 1.7 but i just wanted to make sure of which would be the best choice first.

 

wrong forum bud. 1.6 rr are a common valvetrain upgrade on a lt1.

 

 

about 6%

 

KYLE14:

Helpful hints.....

1. Add a "signature" with basic info about your car, including year, model, engine, tranny and any major mods.

2. Post in the correct forum. You can't post questions about LT1's in the "LS1/LS6/LS......" forum and expect to get answers related to your LT1. If your question was "generic", relating strictly to the meaning of the "X" in the rocker arm terminology, you could have posted on "General F-Body Tech & Info".

 

Kyle, don't take offense to what I'm about to say, but. If you have to ask such a question, you shouldn't be doing it. Valve train components are the trickiest of the mecanical parts in the engine to have them all work in concert with each other. You have a lot more reading to do before you should attempt anything with the valve train.

Here is some suggested reading. Don't let the fact that the comp-cam site says catalog. Their catalog is very helpful with tips and suggestions.

http://www.compcams.com/technical/Ca...07/104-107.pdf

http://www.chevyhiperformance.com/te...ics/index.html

http://www.compcams.com/technical/Ca...106-07/264.pdf

There is a hole lot more out there, just using google would be a start.

Do as Injuneer suggested also.

 

MODS:
CAI
headers
y pipe
no cat
full exhaust with dynomax bullet muffler in place of cat
4l60 (non-electric)
hurst hot shift

i got a cam, valve springs, roller lifters, ported heads, 3.73 gears, and now waiting to see which roller rockers would be best. i will not be doing the installing though...i will only be watching and learning. want to install everything at one time though. sorry about the wrong forum guys.

 

Hi Kyle, was the cam installed when you bought the car? Most people installing cams upgrade the springs and rockers(putting in roller rockers) too so it's possible you may have 1.6's RR put in already.

 

no i have the stuff ready to install. the stuff in the list is what i already have in it. the stuff i mentioned below in the paragraph are the things i have besides the roller rockers and roller lifters that i am getting installed as soon as i figure out which ones would be the best for my app.

 

More detail about the components you have ready to install are needed to answer your question.

Which cam (specs), which springs (specs) will you be having installed?

Honestly, if you are having a reputable person install this stuff for you, they should be well prepared to answer the question of which ratio rocker to use.

Oh, and BTW: Stock Lt1 lifters are roller lifters .....

Thomas.

 

es i know they are roller lifters stock but all cams do not wear the same. therefore it is good to get nw lifters when you install a new cam. the cam has .490/.490 with stock heads rr and springs... i want more. it has a 114 lobe separaion, and 290/295 advetised duration. yet again i want more out of it. lunati springs with .725 max lift. open pressure 556lbs @1.250, seat pressure 142lbs@1.940. is that enough