flyingfool

first I'm wondering what the stock rocker ratio is on the L83?

second, what can I safely increase the ratio too, before causing damage to valve tip, or valve guide?

Thanks for any info you can share!!!

G Atsma

If the LT engines are the same as LS engines, the ratio is 1.7:1. I have not heard that has changed.
Not sure if anyone makes different ratio rockers for those engines yet. Might be better off changing the cam.

Jimbo1367

Gen V LT1 has "Rocker Arms: Cast Roller Trunnion, 1.81:1 Ratio" from all the info I've read. The was taken from PACE Performance.com Who knows if a 5.3L is the same ratio or not.

G Atsma

Whoa! So they DID change the ratio. Good to know!

flyingfool

I just found some tech data saying the DI L83 is 1.8:1

64post

iTrader: (5)

Wrong, 1.8 is the rocker ratio.

G Atsma

Read the WHOLE thread next time (particularly post #4). The new ratio was acknowledged already.

flyingfool

could this be one reason the AFM lifters are failing? due to such high rocker arm ratio? too much stress on the AFM lifters..

G Atsma

There are thousands of L83 engines out there running without failure. You have a different problem.

00pooterSS

iTrader: (40)

You probably won't just find someone that knows the answer yet. I haven't seen anyone mention going to higher ration rockers yet and do they even make high ratio gen 5 rockers yet?

My advice is it would be a much better plan to cam it the way you want and ditch the AFM lifters while you're there and don't jack with the stock rockers.

Besides if you do a higher ratio rocker you'll need upgraded valve springs too. Just another reason you might as well just do the cam and get rid of all the problematic parts.