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L67 Valve Springs?

J

jsnyder49090

New member
I am using a comp cam 512/520 lift I am also using Y/T 1.8 Rockers.What is the least spring I can use? So much conflicting info and where the info comes from I question.Is there any drop in springs I can use and not have to buy retainers?I am a fan of using the least spring possible.
 


most if not all aftermarket springs for this engine are based or taken from the LSx series engines. so to get proper retainer spring fitment and final install height you will need matching retainers.

the next step up from stock are the L76 retainers that came on the 08 g8 gt with the 6.0L engine. these are what i have and im still debating to go with titanium retainers or just reg ones.
 
Are there any drop in springs that will work with my cam and rockers? And use the stock retainers? I was just going to use LS6 springs but someone said they are only good for 480 lift with stock install height and then something about eating the tensioner idk?These spring threads are a joke so much misinformation hoping some of you will sum it all up.
 
As stated above all the aftermarket springs people use on our motors are designed for LS based stuff so they all have installed height of 1.800 as opposed to our stock 1.72 . retainers are cheap though, i got my l76 retainers new from the dealer for around $3ea. All the stiffer springs will tear up the tensioner too, mine broke the tensioner and wiped out the cam angle sensor magnet at the same time around 8k miles. The only way to get around that is the double roller timing chain.
I definitely wouldn't use l76 springs for this application and I'm a huge advocate for them being $2 ea. They are only rated for around .530 lift though and you will be well over that with the 1.8's. With the correct retainers ls6 springs should be good to .570 which if I'm doing my math right half asleep here still isn't enough. Looks like you might want to just buy the good stuff and be done with it. What is your idea behind wanting to run the 1.8s with the cam anyway? Seems like it would make more sense to just get a bigger cam :th_shrugshoulders:
 
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I enjoy reading someone ranting and complaining while trying to get an answer. Somehow it makes me want to give them crap instead of good answers. Especially when they are aiming to go against conventional motor building logic.

Spring install height. Take some measurements. When we use LS based springs with modded retainers, we don't get the correct install height.
Stock install 1.72x"
Modded install 1.78X"
Correct LS install height 1.800"
 
I hope you have well done heads... Why are you bothered by using modded retainers? Its not like its a high ticket item.. If I were you id run 130s or 150s... Running less than that is asking for valve float. Maybe ok on 105s for awhile but whats the point?
 


Cam specs are 512/520. I bought the cam first and was only going to cam it but found some rockers and liked the idea of the roller tip and being a little lighter.My intentions where to build a mild engine that would not have reliability issues.I knew the rockers would likely need bigger springs but it sounds like more trouble than what its worth right? Should I just trade the 1.8 rockers for 1.6 or what would you do?Bill I just couldn't find any good spring info on here nothing more lol but I will say there is a hell of a lot of information and knowledge here if you can get them to share it lol
 
There is a good amount of knowledge, however it can be tough to find. It was the way you went about it that tweaked me a bit.

Most of the vendors also have the springs and spring rates listed. That would explain why the LS6's beat up the dampener more than 105's. Idle has a bit to do with that also.

On the roller rocker vs the stocker, Darkhorizon and GTPower would be good to look up. While no one has done the measurements, it's been mentioned that the stock rocker when pushing down the valve tip may be as high as a 1.8 ratio. Based on the square pad it has for a tip.
 
that's the specs off the cam card its a comp 76-000-9, 512.intake 520.exh 113 LSA.I was going to just run the cam but thought the rockers would be better but it sounds like its going to be more problems than what its worth right?What am I better off doing just running the cam with some 90 lb springs or the rockers also?I myself question the rockers making that much difference in lift I am sure there may be a little but what are stockers 1.66 or 1.8 ?
 


What is your duration?


Stock rockers are not a fixed ratio. The higher the cam lift, the higher the rocker ratio.
 


even with the rockers ? are there any difference in the blue or yellow? use stock retainers? Or should I just run the cam only? Its a mild motor with 3.5 pulley and the usual bolt ons ? Do you really think these rockers will add 0.60 to the cam?I am thinking if they do its a little wilder and have to run more spring that I wanted?
 
Just use your stock rockers. I'm doing some assuming here, but it looks like you will need some head work if you want to run the roller rockers, and will probably need some heavier springs.

Get the yellow springs. Or, you could get some PBM 110's, or PAC 105's. Either way, you need to get an LSx style retainer. The modded retainers ZZP, WBS, and Intense sells is what I would recommend.
 
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