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Springs for 1.85 rockers

4K views 23 replies 9 participants last post by  dblaron 
#1 ·
Thanks to an awesome wife and a suggestion from an abominable friend, I ended up with a set of 1.85 rockers for Christmas! I ordered the 1.450 pushrods already. My question to the guru's out there. I picked up a new set of ls3 springs from a member on here, these should be fine for the rockers, correct? I still have the stock cam installed, I believe I should be ok but I wanted to hear from some experts. Thanks
 
#2 ·
You need to know at what lift the springs will bind at. Then just do the math and see if the 1.85 rockers would put you over what the springs will bind at. Its always best to leave a little room to play as well, say the springs bind at 700 lift then try to keep the actual lift at the valve no more then 680 that way you never come close to making the springs bind.
 
#3 ·
From the GMPP catalog

12586484
Valve Springs (not shown)
• Beehive style springs • Standard LS6/LS3 springs
• Use cap P/N 10166344 • 1.250" @ 295 lbs. pressure
• 1.800" installed height • Max lift .570"
@ 90 lbs. pressure

I was thinking that because they are good to .570 lift that I am good.

This is quoted from another board. I hope he doesn't mind.

"The test engine was a 2009.5 G8 GT with a 6.0L L76 engine with active fuel management (DOD). All AFM motors are saddled with a very small 200/208 .472/.474" 116LSA camshaft. The 1.85 rockers would effectively increase the lift at the valve from .472 to .514". This small but noticeable increase in lift will get the large intake valve further away from the cylinder wall plus into a position where it flows more air. Effectively my engine now has a 200/208 .514/.516" cam."

Anybody see any reason they wont work?
 
#4 ·
I'm not sure if the LS3 springs will be stout enough. The L92 heads have heavier intake valves and will have a higher demand on the springs than LS3 heads running the lighter valves. I would recommend some PAC 1218 or 1518 springs for peace of mind.
 
#6 ·
That's exactly what I was looking for. Thanks Pat. I guess I will have some springs for sale if you are telling me they won't work. Would those springs you recommend work for a future cam upgrade? (Yeti cam)?
 
#5 ·
doi need springs and everything or wll 1.85 rockers work alone?
 
#8 ·
Yes. I ran mine with stock springs and valves with no issues. If you are worried, you can shim the LS3 springs .030-.050" when you install them. Even shimmed .050 still gives you .005" from max lift range on the spring.
 
#9 ·
Found rockers so my question is wht would happen if I just change the rockers and nothing else? Trying to avoi d the springs since they are a pain


Sent from my iPhone using AutoGuide.com App
 
#10 ·
Stock or LS3 springs are fine for the .514" lift. The LS3 cam has more lift anyway.
 
#15 ·
Install your new push rods by putting them in there where the old ones came out.
 
#16 ·
so sticking with stock springs might allow for a little more HP over a heavier spring? u just *might* float a valve under extreme conditions??
 
#17 ·
Basically. Valve float can cause issues that are not cheap to fix. For the peace of mind I would sacrifice a negligible amount of HP for peace of mind.
 
#18 ·
I hear ya, thanks again Yeti
 
#20 ·
There's an idea thank you!
 
#22 ·
What are you refering to? The springs or rockers? The springs are a direct swap, the rockers, for whatever reason, hit the valve cover on yeti's car. Nothing a dremel can't fix. I used an air die grinder but the idea is the same.

http://www.g8board.com/forums/showthread.php?t=57832

Others have installed the rockers with no issues so I'm curious if this was just a flaw from the factory in yeti's valve cover. Check out his thread. They were very straight forward to install.
 
#24 ·
Yea, what springs? I paid almost 600 for my rockers.....
 
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