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Toying with the idea to put Yella Terra 1.8 rockers on my LS2. The long block is stock. I assume it would be a good idea to change the springs while I'm at it. What would be a recommended set of valve springs for 1.8 rockers on a stock LS2 cam? I did a search and the comments seem to be all over the place and some of the suggested springs are no longer available.
 

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seriously though, this is the thing with roller rockers...

they are a pita and totally unnecessary with a stock valvetrain.

you have to worry about shimming to get the right wipe pattern on the valve tip.
you need stronger springs
stronger springs means more stress on your rockers and other parts, like your timing chain.
aluminum fatigues and breaks.

the stock rocker is perfect. it is light on the valve tip and remains centered on the valvetip through whatever lift a stock cam will take it to. the trunnions don't wear out, either, lol.
 

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Because of the 1.8 or because of the brand?
i see what you're trying to do, i think about it now and then as well. i have been recently. shoot, i think i even (maybe jokingly) mentioned it to you, lol.

it's just better to do a cam.

also, about the balancer, yeah i know you got one, but it's advisable to run a GOOD balancer. slp or powerbond is fine if you are stock internals, and if you run an ASP, buy a kia now. once you go serious, like it seems you are about to, you really do want something that works well.
 

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You get the springs rated for the cam lift. So something identical to stock. Wouldn’t waste time on fancy rockers for a stock cam. I’d do a trunion upgrade if I really wanted to throw money at it.
 

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Discussion Starter #8 (Edited)
i see what you're trying to do, i think about it now and then as well. i have been recently. shoot, i think i even (maybe jokingly) mentioned it to you, lol.

it's just better to do a cam.

also, about the balancer, yeah i know you got one, but it's advisable to run a GOOD balancer. slp or powerbond is fine if you are stock internals, and if you run an ASP, buy a kia now. once you go serious, like it seems you are about to, you really do want something that works well.
Well, I do have an SLP and the internals are all stock so.... It has been on there for 8 years or so, has never caused a problem. I have no plans to go into the internals of the engine (well, other than the thoughts on rockers). The car is far from being a daily so I can play with it a little, but don't want to make it unreliable.

Doesn't seem like anyone thus far is a fan of 1.8 rockers on a stock cam. Good info, that's why I asked.

The reason I even brought it up was I searched for and found a number older posts here and on LS1Tech.com about 1.8 rockers being installed with decent success but none seem to mention a specific spring that was used. But if that's all bunk and 1.8s are not a good idea, that's good to know.
 

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You can still do it, and you should see a gain. It's just that, with the hassle involved, might as well go cam.

Swap springs and spend hundreds in a set of rockers, and get like 8 whp.

Go a bit farther and get 50-60 hp with a cam.
 

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Discussion Starter #10
C'mon, I'm just trying to find ways to spend more money without spending TOO much money.

Joking aside, I have a good friend who had his Z06 cammed with new heads and went catless and while it is a blast to drive, it is now STUPID loud (which he hates) and has cam surge (which he hates). I get it on both counts as I've driven the car a bit myself. Point being, just a bit of evidence on the CON side of doing a cam. I know I could just do a milder cam, but still sometimes doing big changes can result in undesirable consequences.

I have a silly cammed BBC in my Chevelle wagon which is also stupid loud. And while I like the car, I chose my GTO and my other (stock) Chevelle over it most of the time when it is time for a fun drive. Just sayin', I'm apprehensive about making the GTO an unhappy experience by going too far.
 

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Just call a place and have a cam spec'd.

I have a 230/232 @ 114 that has about 3 deg's of overlap. Could i make more power with a different cam? Yes. It's a cinch to tune and drives great tho.

There are endless options with cams.
 

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If the car bucks because of the cam it’s either a tuner issue or user error. Driving outside of the range the cam is meant for.
 

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Some thoughts for and against

Positive:

1.8 rockers are equivalent to a cam with .550" lift or so (stock is .524").
Results between 15-20rwhp (according to quick google search)
Very easy to install the rockers. Measuring lash and preload is very easy with a checker spring.
Contrary to forum post the problems with AL rockers are in the past. Yella and scorpion both addressed their design issues.
Lower valve guide wear

Negatives
cost. Your looking at atleast $1000 in parts plus $500 for a dyno tune
To get the most out of your setup you will buy .600" springs however if you ever upgrade to a cam you will have to buy heavier springs
If you ever buy a cam you will have to buy new pushrods as the base circle changes


Answer some popular questions:

But muh rockers will break cuz duh fatigue!

No they shouldn't break. Engineers take AL fatiguing into account.

But steel design has lower inertia! I saw it on LS1tech.
The steel design may have lower inertia (haven't actually seen measurement of this) however AL may be stiffer. AL is less dense so you can put more material off the neutral axis without hurting the moment of inertia as much. You could have the lowest moment of inertia steel rocker but if it is forever flexing back and forth what is it worth?

But duh roller tips dont help dat much.
They should return better guide wear and hp because the tip will not scrub on the valve tip. Also if set them up right the rockers should have a tighter sweep pattern.

My opinion
Most of the info out there is bogus with no numbers behind it. Getting actual inertias/stiffness from these parts would be difficult without being the producer. If it were me I would do the rockers assuming all other bolt ons are done and there aren't plans in the future for a cam. Its easy and a decent gain for 1k.
 

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Some thoughts for and against

Positive:

1.8 rockers are equivalent to a cam with .550" lift or so (stock is .524").
Results between 15-20rwhp (according to quick google search)
Very easy to install the rockers. Measuring lash and preload is very easy with a checker spring.
Contrary to forum post the problems with AL rockers are in the past. Yella and scorpion both addressed their design issues.
Lower valve guide wear

Negatives
cost. Your looking at atleast $1000 in parts plus $500 for a dyno tune
To get the most out of your setup you will buy .600" springs however if you ever upgrade to a cam you will have to buy heavier springs
If you ever buy a cam you will have to buy new pushrods as the base circle changes


Answer some popular questions:

But muh rockers will break cuz duh fatigue!

No they shouldn't break. Engineers take AL fatiguing into account.

But steel design has lower inertia! I saw it on LS1tech.
The steel design may have lower inertia (haven't actually seen measurement of this) however AL may be stiffer. AL is less dense so you can put more material off the neutral axis without hurting the moment of inertia as much. You could have the lowest moment of inertia steel rocker but if it is forever flexing back and forth what is it worth?

But duh roller tips dont help dat much.
They should return better guide wear and hp because the tip will not scrub on the valve tip. Also if set them up right the rockers should have a tighter sweep pattern.

My opinion
Most of the info out there is bogus with no numbers behind it. Getting actual inertias/stiffness from these parts would be difficult without being the producer. If it were me I would do the rockers assuming all other bolt ons are done and there aren't plans in the future for a cam. Its easy and a decent gain for 1k.
Stock rocker tips don't scrub with the stock cam, bruh. Stay under .550 and it won't happen. It also doesn't side load the valve until you start going over that. Lastly, guide wear is still negligible with a stock rocker and aftermarket cams until you are a bit over .600. Just stick with the oem powdered metal guides.

And i could argue that no matter the design, the steel roller tip and support around it will probably weigh more than the stock tip. I wouldn't run any roller tip with stock springs, lol.

If i were doing max effort, aftermarket heads, .700+ lift, oh smurf yes, rollers all the way. Not some cheapo scorpoins or yeller teller either. Cheap trash breaks. Smurfing stock steel oem rockers have broken, i wouldn't trust some cheapo aftermarket unit, improved design or not.
 

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Stock rocker tips don't scrub with the stock cam, bruh. Stay under .550 and it won't happen. It also doesn't side load the valve until you start going over that. Lastly, guide wear is still negligible with a stock rocker and aftermarket cams until you are a bit over .600. Just stick with the oem powdered metal guides.
Metal on metal sliding is scrubbing. I did not say it was significant. However a roller will be less.

And i could argue that no matter the design, the steel roller tip and support around it will probably weigh more than the stock tip. I wouldn't run any roller tip with stock springs, lol.
I definitely agree not to run this stuff on stock springs. However in my point above I was not arguing AL rockers are lighter (they aren't). I was arguing they very well could be stiffer.

If i were doing max effort, aftermarket heads, .700+ lift, oh smurf yes, rollers all the way. Not some cheapo scorpoins or yeller teller either. Cheap trash breaks. Smurfing stock steel oem rockers have broken, i wouldn't trust some cheapo aftermarket unit, improved design or not.
I don't think either company is bad. Matter of fact I think they both offer good products! Yella terra is used extensively on Ls road racing engines in Australia. and I know Scorpion is made in the US and has been around forever. If rich wants to be on team steel slp and comp both offer steel 1.8 versions. For which I still stand it could be a good mod for someone not wanting to go in the engine


Reason for editing: getting used to how to format stuff on forum
 

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As far as the claim for 15-20 hp, i disagree with a early year ls6 spec cam.

SLP doesn't make crap anymore.

And you think the stock tip scrubs under .550 lift?

So millions of LS engines with stock cams and valvetrain are experiencing unprecidented valve guide wear because... oh wait, they don't.
 

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The power increase between the early and late year model ls6 cams was from increased overlap and different exhaust valve opening and closing events. That's where most of the extra power came from. That was the difference between 385 and 405 horsepower. Lift alone didn't do it.

You're getting a tiny change in lift with just a set of rockers. It will gain maybe 10, probably 5. I did 1.8 rockers once and saw a minimal improvement in trapspeed. Maybe 1 mph, maybe zero because i had also swapped on a ported ls2 manifold at the time.

It really isn't worth the time and effort if you're not swapping a cam in.
 

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As far as the claim for 15-20 ho, i disageee with a early year ls6 spec cam.

And you think the stock tip scrubs under .550 lift?

So millions of LS engines with stock cams and valvetrain are experiencing unprecidented valve guide wear because... oh wait, they don't.
When a rocker tip with no bearing slides across a valve tip its called scrubbing. Im not implying parts are being damaged. Its just a term.Rolling will always have less (scrub "friction") then sliding. It is however small like you are pointing out. But still an advantage of roller rockers
 

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When a rocker tip with no bearing slides across a valve tip its called scrubbing.
I get that, homie. Same how bearings and cylinder walls wear, but it's not a problem until it happens faster than it should.

People put x00,000,'s of miles on ls stock valvetrains. Whatever happens at the valvetip is the least concern. It's not an "advantage" if you're trying to eliminate a problem that is so negligible as to be considered, for all practical purposes, nonexistant.
 
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