1:6 rockers
Thread Starter
Instructor
Joined: Apr 2011
Posts: 127
Likes: 0
1:6 rockers
I've read a thousand posts about people wanting to run 1:6 rockers. I know that you can, but every post that I read has someone saying that the springs will fail, and it is a bad idea in general. I am wondering if anyone has run them for a long period of time and what has your experience been with them? How was the reliability? Gas mileage? If you bought another LT1 would you spend the money to run them again? I'm thinking of running a set just to see, but I'm not interested, at this point, to rebuild my valve train to do so. Thoughts?
Race Director
Joined: Jan 2005
Posts: 10,641
Likes: 13
From: Slidell Louisiana
You'll probably have to change your valve springs IOT run 1.6 rockers. I've been running 1.6 rockers on my dd since 2005 but I have a higher lift cam too. .61x lift at the valve. My lt1 hits 7,100 rpm almost daily no drama.
MIke
MIke
Le Mans Master
Joined: Sep 2004
Posts: 6,019
Likes: 568
From: Conroe Texas
a stock lt1 cam with 1.6 rockers is the same lift, +/-.003, as a lt4 cam with the stock 1.6 rockers. springs should be fine, only about .03" at the most more lift. that's right at 1/32". and the valve reliefs in the lt1 piston are deeper than the lt4 piston.
Drifting
Joined: Feb 2006
Posts: 1,423
Likes: 96
From: Magnolia Tx
I ran a set on stock springs in an IROC-z from about 40k miles to 200k. At about 175k miles, it would float the valves at 4500 rpms. It was pretty tired by then. I run them on my Vette now with no issues.
Race Director
Joined: Nov 2003
Posts: 12,221
Likes: 446
From: Overland Park Kansas
2020 Corvette of the Year Finalist (appearance mods)
C4 of Year Winner (appearance mods) 2019
It never hurts to consider changing springs every 20 years or so. 
Seriously, you can (or have someone else) change springs w/o removing the heads. I'd consider that part of the upgrade...and the peace of mind you'll want when revving the snot of it -- to see how much more it'll have.
JMHO
Seriously, you can (or have someone else) change springs w/o removing the heads. I'd consider that part of the upgrade...and the peace of mind you'll want when revving the snot of it -- to see how much more it'll have.
JMHO
Team Owner
Joined: Dec 2000
Posts: 90,675
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From: SE NY
Cruise-In II Veteran
I am wondering if anyone has run them for a long period of time and what has your experience been with them?
Safety Car
Joined: Nov 2009
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From: Adelaide South Australia
Racer
Joined: Dec 2012
Posts: 347
Likes: 25
From: Rockford Illinois
I just finished up installing 1.5 intake/1.6 exhaust roller rockers with new springs, pushrods and seals last week. The performance increase to me is incredible. Where it's the best is what I did not expect, at 40mph and above. I have had this car since 1989 and it never moved like this and I believe the new springs hand a hand in waking this up.
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Instructor
Joined: Sep 2011
Posts: 140
Likes: 7
From: Fort Ripley Minnesota
To gain the full potential of the 1.6 rocker arm you really should consider changing your old valve springs, the mechanisms are only as strong as the weakest link!
I have 1.6 in my 383 and I have ZERO valve train issues at or above 6000 RPM. Anything above 6 Grand on a TPI engine is for nothing.
I have 1.6 in my 383 and I have ZERO valve train issues at or above 6000 RPM. Anything above 6 Grand on a TPI engine is for nothing.
Race Director
Joined: Jan 2005
Posts: 10,641
Likes: 13
From: Slidell Louisiana
Race Director
Joined: Jan 2005
Posts: 10,641
Likes: 13
From: Slidell Louisiana
But LT4 springs are different than LT1 springs.