HioSSilver

iTrader: (8)

I've had the stock rockers on it before. The car has not always had the rr's on it. So the answer to your statement is your wrong.

The car ran better with the 1.7 roller rockers vs the stock rockers also.

Paul Bell

iTrader: (9)

Interesting dyno results Hio.

Just for the sake of argument/comparison, lemme toss a question into all this.

Let's say you've already spent the money on a good cam, lifters, pushrods, springs etc. Would THEN going to 1.8 still show a gain over 1.7 arms?

HioSSilver

iTrader: (8)

I'm sure it would depend on the cam. ..... The whole combo really. But if you look at the gains in the below 5000 area I would have to say there is a very strong chance it would help almost any combo. I would think a cam like a gm Hot cam could have even more gain.

I gonna put some on my truck just for the low/midrange power.

I'll tell you what else the roller rockers do. They seem to let run free'er at high rpm. It's actually a very noticeable difference at the rpm I turn.

DREAMZ28

iTrader: (1)

With a stock cam and it's ramp rates it could be OK, but with aftermarket cams I wonder how it would be controlling the extra weight.

HioSSilver

iTrader: (8)

IDK were the limits are or with what cam. I do know a ls6 cam has pretty fast ramp rates. I'm not sure how it compare to aftermarket cams. You can also put ti retainers on to save some weight over the valve.

slt200mph

iTrader: (42)

Can't cure stupid...

TurboBuick6

iTrader: (2)

We had a bone stock LS1 with an LS6 cam on the spintron and hard a very hard time controlling the valves with a 1.8rr. So much we had a 1209X 0.050" from bind and still couldn't get it. Only cure was short travel lifters. We concluded the extra pressure to control the rr's was too much for the OE lifters (Caddy race Lifters).

KCS

iTrader: (20)

Your economic argument goes right out the window if you have to pay for labor.

dannyz

That's rather uncalled for, isn't it?

HioSSilver

iTrader: (8)

Was you using a beehive spring?

Also the ls1 valve is heavier than my ls6 valves. This is why I said earlier it would depend on the combo. It seems to work on my combo fine.

I have had 1.7 rr's on the stock ls6 valve spring and were fine to 7000. I used a set of PSI beehives with my 1.8's and ti retainers. The PSI springs are only slightly more stiff than the ls6 springs but were good for .625 lift.

At what pressure do the stock lifters give up?
I think anytime you mess with hotrods there is little room for economics....lol
For real......for either side of this discussion. Since turbobuick is involved there could be some good info in this thread and some insight to the why's and how's of it all.

96capricemgr

iTrader: (1)

IMO you shouldn't be paying labor for mods like this because if the car is that modded you should be able to troubleshoot it yourself and do the work yourself.


So with the retainers you used I really lowballed the cost of this.

The true LS6 valves is a good point not strongly enough considered earlier in this thread and likely an important part of why you are getting away with something pretty well recognized to normally cause problems.

KCS

iTrader: (20)

Exactly. Swapping rockers is probably something someone could easily do in an afternoon in their own garage/driveway as opposed to the time and/or expense of a cam swap.

HioSSilver

iTrader: (8)

Now IDK what rr's turbobuick was using. I 'm using Harland Sharps. I also don't know the difference in the valve weight or how it would ultimately affect the float of it. I do know that turbobuick was using a much stouter spring than I am and it is also not a beehive. A beehive will help get weight off the valve. How would my psi's work on a ls1 valve with a 1.8 rocker vs what turbobuick did????

Here are the specs for the springs.

----------------od-------id-------Install height----open load------spring rate-----max lift
Turbobuick--- 1.324--- 0.680--- 160 @ 1.800--- 510 @ 1.100---500 1.000-- 0.750

PSI beehives- 1.290"--- .630 --- 130lb@1.800 --- 370lb@1.175---384 1.100-- .625

I run the PSI's with a 1.8 rocker ls6 valves with ti retainers to 7000 w/o issue.

Paul Bell

iTrader: (9)

I'm bringing this to the top again because I want everybody to understand that stock rockers are good up to .550 lift-and I'm sure they'll go a little further.

Here's some good rocker reading:

(about halfway down starting with "Running High-Lift Camshafts With OE LS Rocker Arms")

http://www.gmhightechperformance.com...e/viewall.html

96capricemgr

iTrader: (1)

I thought the LS6 cam was up in the .550 lift range .548/.551? Best I can find the LS6 rockers have a minor bearing upgrade but are the same as LS1 otherwise.

So the magazine is claiming GM themselves sold warrantied LS6 cars exceeding the recommended lift on their own rockers?


I don't doubt that the .608/.612 lift is far enough that stock rockers begin to scrub, at the same time given the LS6 cam specs, .550 lift is going to be well within the limit.

I would have to pull the valvecover off the truck to look but I wonder if shimming or milling of the rocker pedestal mount is needed to refine geometry and just so rarely done and that is a contributing factor.

HioSSilver

iTrader: (8)

Good find Paul.

TurboBuick6

iTrader: (2)

.650 lift on stock rockers. The pedistals were milled to change the wipe pattern and geometry.

96capricemgr

iTrader: (1)

There is a BIG problem with the forums. People only reply to things they wanted to hear. I point out GM used the rocker to .001 beyond what the magazine says it is good to and the only reply to that is someone praising the article find.

My pointing out the lift GM used them at severely discredits the whole basis if the article without any speculation of opinion.

If the magazine article was valid we would hear about every stock LS6 having problems much less all the modded cars that use the LS6 cam much less all the aftermarket stuff.

As I said there is going to be a point where stock is lift limited but the idea that .550 is that mark is plain bull.

HioSSilver

iTrader: (8)

The problem you run into and maybe didn't pick up on was the longevity issue they spoke of in the article. Most don't run their .600+ cam for 100k or more. They throw a cam in it with little regard to how long stuff will last. It's not that the stocks rockers don't/won't do it. It's about what needs to be done to make it live a long time

Besides.....I don't think .001 is going to be a breaking point on many valve train issues.

96capricemgr

iTrader: (1)

My point was that if GM used those rockers at .551 that completely disproves the magazine's claim that .550 was the limit. I will agree that by the time you are getting over .600 and then blindly slapping it together without checking geometry you likely would see the issues they did with miles.

As Turbobuick6 said geometry needs to be addressed and almost nobody bothers with that.

You are still seeing what you want to see rather than the truth. Truth is issues would creep in slowly with additional lift, there isn't going to be a exact number that is the issue and the issues are going to begin sometime solidly past .550 since GM sold cars with that lift and nobody has tried a class action claim.

If the magazine had attempted to address geometry and had pics of a good wipe at original installation your argument would have some merit. They halfassed the install as MOST folks do and then had problems and refused to actually learn what happened and just said "more money is the answer".

Before you go seeing what you want to again, I do believe that over .600lift without addressing geometry will give the results the magazine got.