Stroker396@APF

iTrader: (18)

Check out this months edition of GM High Tech Performance. (May 09)

Many of us have added a cam to our LS1 and reused our stock rockers (myself included), well as it turns out they are only good to .550 lift.

You added the Springs, hardended pushrods and though you were good right? Me Too, but...

If you cam lift is larger then the nose dives into the valve and will wear out your valveguides, eventually robbing the power you worked so hard to get.

With many peole on a budget these days, I don't know about you but I don't have 5 bills to drop on some rockers.

Fortunately I was just getting ready to put CAT Aluminum and Stainless steel roller rockers on sale (ironic timing)
Check it out http://performanceautopartsonline.co...hp?cPath=38_44


Here are a couple of excerpts




I will add the link back to the Sponsors forum when I post the whole sale thead tomorrow.

conan

iTrader: (5)

Good info! Now I have to think about spending more money on my engine

SPLATT

iTrader: (1)

Do the CAT Rockers need any modifications to install, as far as anything on the heads? also, are there any results with them yet? they look great for the price?

1SLwLS1

iTrader: (6)

I thought everyone had just said this article was useless...

SOMbitch

iTrader: (8)

But a few guys on here have reported going 60-70K+ so it really makes me wonder.... I am at 17K now on a 598/612 cam with no apparent isssues.....

massls1guy

iTrader: (9)

That issue has been out for a while. This isn't the first thread on the subject:

https://ls1tech.com/forums/generatio...k-rockers.html

https://ls1tech.com/forums/generatio...ockers-no.html


.

2000PewterZ28

I would leave the china rockers off my car.

SPLATT

iTrader: (1)

well even so, i was looking at getting some newere than stock rockers and the CAT ones look nice, im just wondering how they perform, If its good i will have absolutely no problem ordering them

SPLATT

iTrader: (1)

Well, if they work, they work. I just need something to sit on the LS1 until a 370 is finished up. Id like to make the stock motor last as long as i can.

Chrome355z

iTrader: (1)

Guys this is the exact reason for running roller rockers with aftermarket heads because the guides (bronze) are soft.

STOCK HEADS IT IS NOT A CONCERN. Look who wrote the article and what they sell. Think!

ramdaspadhye

iTrader: (3)

Had a set of procomp roller rockers on a sbc 383, 1.5 ratio with a lunati voodoo .515 lift. Procomp gets a bad rep, but I had absolutely 0 problems with them. They are built nicely and very nicely priced (125 a set for full rollers for sbc) and are machined to accept big springs. Procomp makes a set of stainless RR for the LS motors around 180ish I think, not 100% sure. Might be worth looking into. Their new stuff is far superior to the stuff they USED to produce.

BAMF

There is a guy intown with a Cartek 447 in his corvette and he was shocked that they used the stock rockers, reason being light weight...stronger springs for a heavier rocker would crush the comp R lifters he has...

69LT1Bird

iTrader: (1)

I call BS of this for production heads, aftermarket maybe its true, if so, they should put in better guides.

This is from the 2009 GMPP catalog. Remember, GM has to hours and hours of durability testing because they warranty their parts so I am pretty sure I would trust them before a aftermarket supplier. Robin L on here can attest to the testing that goes on for the performance parts group. The only thing they really say is no stock springs. The springs are the reason you see all of the other GMPP cams at .550 or below because they can use proven off the shelf springs and so can the customer.

LSX CAMSHAFT
The range of high-performance camshafts for LS engines expands
in 2009 with our new LSX454 cam. It was developed by GM
Performance Parts’ LSX performance engineers, who designed it
to deliver great high-rpm performance with excellent street manners.
The LSX454 cam is a high-lift, hydraulic roller that was originally
developed for our LSX454 crate engine. It maximizes the
potential of big-displacement engines at high rpm. Maximum lift is
0.600/0.600" with 1.7-ratio rockers and 0.635/0.635" with 1.8-ratio
rockers. Duration is 236 degrees on the intake side and 246 degrees
on the exhaust side, with a 110-degree separation angle.
NOTE: Not compatible with production-style variable-valve timing
configurations or production valve springs.

PREDATOR-Z

If you have .600 lifts and expect 100.000 miles, you are **** out of luck. Yes we are pushing the limits, yes we know that, but we love the power
Just like springs, ask any "honest" vendor and they will recommend "refreshing" your ported heads after XXX miles.
It is just part of modding maintenance.
That is just part of the game

69LT1Bird

iTrader: (1)

Well said, but the article makes it sound like you are going to have issues right away and you need to run out and buy now rockers, nice advertising for the rocker manufacturers I guess.

WS6TransAm01

iTrader: (13)

I have been running stock rockers with cams over .550 lift since 2002. Obver 40K miles, over 350 track passes, and never had an issue.

If your valve train is set up right, with the right valve height, right pushrod, right preload, you will be fine.

I would imagine these problems occur on those cars who were setup by people with less that desirable knowledge.

Stroker396@APF

iTrader: (18)

I knew this argument would go both ways. To me the article made is sound like it was a problem in the long term not the short term. However I have 12K on my setup and with a slight exhaust leak (long story) I get that sewing machine sound. I plan to upgrade my springs from comp 918 to Isky 195 and add the Stainless rockers (my lift is .595/.598).

I have seen the CAT rockers and the quality looks fine (I too am not a fan of Chinese products and so am particularly scrutinous of anything from there)

The problem they mention occured on a set of 5.3 heads over some time.

I did not replace my rockers at the time of the cam install because I researched it here and no one was doing it. But in light of this information and for the price it seems wise to do the upgrade IMO.

The fact I am selling rockers is just an ironic coincedence as to the timing.

I will be installing them soon I can let you know how they work out (out of town this week).

TooLateVTEC

iTrader: (2)

Well im going to agree that its a marketing gimick as well.

The C5 Z05 from 2002+ had .551/.555 lift cams from the factory...

Just throwing that out there.

topher455

iTrader: (6)

Out of all the carnage I have seen here (alot) I dont think I have ever seen a broken stock rocker or someone who's stock guides wore out causing oil consumption. Arent plenty of guys running 640-650 lifts with stock rockers? I know harland sharp sells an upgrade for the factory rocker bearings. He must think the rest of the design is ok??

WS6TransAm01

iTrader: (13)

not to mention that a stainless steel rocker will be heavier than the stock roker, causing more drain and strain on the valve train...

why would you go to a hevier rocker arm, unless you are going to a solid roller when pre-load does not matter.