KSA Aaron

Does Comp Cam (or others) make a rocker arm kit (similar to 16765-KIT) that has full roller rockers in a 1.7 ratio to fit the LS9? I am assuming that the LS3 and LS9 take the same rockers, as I have been told.


All I have found is the 1.8 ratio.
COMP CAMS ULTRA PRO MAGNUM ROCKER KIT W/ STUDS & GUIDE PLATES LS3/L99/L76 16765-KIT


My fallback position... I know that I can use OEM 1.7 rocker arms which I will wind up spending about $350 to purchase, so I am considering an upgrade. Unfortunately, my overall plan does not allow for 1.8 rocker ratio.


Any help would be appreciated. Thank you in advance.

realcanuk

Ultra Gold but I believe they are 1.72

KSA Aaron

Manufacturer?


Are the LS3 and the LS9 rockers completely interchangeable?


And for that matter, is the LS3 intake a simple bolt on to the LS9 long-block?

realcanuk

Ultra Golds are Comp rockers. I don't know if LS3 and 9 are the same.
I'm using those rockers in 1.82 for years and no issues. I know they make 1.72 also.

CMY SIX

and asking Comp is out of the question? I have Comp "gold race? RR 1.7 they have a 3/8 stud if the thread size in the head is the same, I don't see why not? But I'm not that bright, I would call Comp and talk to a tech and they would tell me which of their products I could use for a given application. but they probably don't know as much as the "forum engineers" I would imagine we will hear from some of them shortly, For my intolerable mention too call Comp Cams

schpenxel

Forum engineer here

What's the question?

CI GS

I'm running the Comp Ultra Gold Race 1.72 rockers on my GS. They are aluminum body, full roller rockers with a lifetime warranty from Comp. The part # you're looking for is 19028-16. Here's the best deal I've seen on them, from a forum vendor. That's a full $90 less that what I paid for mine from Summit, who lists them for ~$577.
You will need taller valve covers though, like the taller Holleys, which fit perfectly and look very nice.

http://www.coloradospeed.com/roller-...3-p-29089.html

Here they are installed on my car:

CI GS

You are definitely the forum "Guru", along with that canuk guy.

eprest1983

hey, are you certain you need taller valve covers for these? The JEGS website says these are designed to fit under stock covers. Also, what cam do you run and did these rockers quiet down the valve train at all? I have a 2010 GS with BTR stage 2 cam and considering these.


http://www.jegs.com/i/COMP-Cams/249/19028-16/10002/-1

schpenxel

Old ones used to fit, new ones are beefier and don't

NJ_phil

Thanks for the tip on Colorado speed:

CI GS

As schpenxel already advised, that applied to the old style cathedral port version of these rockers.
You definitely need the taller covers for the Comp L92/LS3 Ultra Gold Rock rockers. I think you may be able to use the shorter covers if you remove the baffle (I've read that somewhere, actually). I didn't want to mess with that and have to deal with the possibility of excess oil getting sucked out via the pcv, so I just ordered a set of the taller Holley covers, which fit perfectly. If you're changing from the stock covers, it's a great visual upgrade as well - provided that you're not one of those folks who has an affinity for those cheesy plastic coil covers.
The rockers did quiet my valve train down a bit. I would still like to quiet it down some more, but that may have to involve me changing out the lifters, and maybe a few other parts at the same time...

CI GS

No problem Phil. That's a hell of a deal, compared to what I paid for mine.
Those guys seem to have the best prices on everything. To bad for me that they don't ship overseas.

NJ_phil

I wasn't even looking to upgrade the rockers but couldn't pass that price up. Hoping they also quiet down valve train noise on my setup. For some reason I hear everything going on in the motor and noticed a very slight tick on the passenger side but only when I'm next to a wall or something and have the windows open. It might be the headers because I can't hear it under the hood with a stethoscope...only next to something bouncing back noise into the cabin.

Nobody hears it but me, so possible I'm going senile.

CI GS

It's senility, or "acute advanced-age mechanical failure phobia", as I like to call it.
I have the same problem, so I know what I'm talking about. It's typically treated with "anticipatory preventative expenditure". Which is what you're doing right now.

NJ_phil

Hey Sammy...Did the pushrod length work out about the same when you switched to the Ultra Golds? I bought new BTR 7.40" set when I put the cam in over the winter and made sure the preload was .060". Hope there's no change for going with the Ultras. Obviously I'll check it again.

CI GS

Hey Phil. I'm pretty sure that the stock 7.4" length could've worked for me, but I wasn't getting much preload on the exhaust side, so I went with a slightly longer (7.425") pushrod on the exhaust and kept the 7.4" on the intake.
In hindsight, I'm sure I could get away with only about 3/4 turn of preload, but I thought I didn't want to take the chance.
You need to check it for your particular cam and see what it needs, because it depends on the base circle of the particular cam you're using and base circle could vary from intake to exhaust on the same cam. It can also be harder than you think to get a really accurate measurement of preload doing it the way I did too, because it can be difficult figuring out exactly when you hit "zero lash", by turning the pushrods in your fingertips and feeling the resistance.
If you haven't read it already, here's a thread that I did when I was doing my rockers, with a detailed discussion between me and Jody (realcanuk) about preload/pushrod length.
https://www.corvetteforum.com/forums...r-ls3-l92.html

seevi

I used the OEM 1.7's but did the comp trunnion upgrade.

CI GS

I would monitor those for wear, because a number of people have reported that they have had excessive wear Idon't the trunnions. The real problem is that you can't see what's happening to them, unless you pull them apart first, or, worse yet, if they fail catastrophically.
In my view, the real problem with those is the design, in that, they have a shoulder around the rocker bolt head recess that prevents proper oiling of the needle bearings. When I installed them on my car, I used a dremel to carefully cut diagonal slots forming a "X" across the two shoulders to allow oil to drain from around the bolt head into the bearing. Even then, I became nervous and after lifting the valve covers and running a magnet around the top of the cylinder head next to the springs, I picked up some metal shavings and decided that was it and ordered the Comp Ultra Gold rockers.
The picture below shows the small metal particles I picked up on the magnet after just dragging it through some oil pooled next to the springs. I don't know if that's supposed to be normal but I didn't like the looks of it.

KSA Aaron

Thanks for the info guys. It appears that the Comp Ultra Gold rockers are the way to go. This is certainly better than spending $1800 on the shaft rockers.


Can somebody post up a picture of the Holley valve covers? I saw a set of Chevrolet valve covers (Ebay special - $200) this past month that really looked nice but remain leery.


Thanks again for all of the replies.