L83 rocker arm ratio?

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Feb 3, 2019 | 11:38 AM

flyingfool

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L83 rocker arm ratio?

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!!!

Feb 3, 2019 | 11:44 AM

G Atsma

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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.

Feb 4, 2019 | 10:11 AM

Jimbo1367

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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.

Feb 4, 2019 | 10:41 AM

G Atsma

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From: Central Cal.

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

Feb 6, 2019 | 05:38 PM

flyingfool

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

Apr 8, 2019 | 07:52 AM

64post

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Quote:

Originally Posted by G Atsma

Wrong, 1.8 is the rocker ratio.

Apr 8, 2019 | 10:24 AM

G Atsma

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Quote:

Originally Posted by 64post

Wrong, 1.8 is the rocker ratio.

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

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Apr 8, 2019 | 11:29 AM

G Atsma

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From: Central Cal.

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

Apr 12, 2019 | 04:40 PM

#10

00pooterSS

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From: Dallas

Quote:

Originally Posted by flyingfool

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.