roller rocker ?

[scotts94_z28]

I was wondering what exactly the advantage was of going to 1.6 roller rockers and what kind of performance increase I would see using them if any. Also if i was to get some what would be the best to go with and how hard are they to install. Is it just a matter of pulling the valve covers or is more involved?

[Craig 94 TA GT]

It took me several hours for the install because I changed the rockers, converted to 7/16" studs, chromemoly pushrods, lifters, and springs. But IMHO, it was well worth it. You have have more upper end power, and the increased lift should give you more overall power as well.

I would suggest you at least change the springs when you do the rockers because on the exhaust side spring, you'll be close to coil bind. The LT4 springs are cheap and decent...and Comp Cams make good sets.

If you go ahead with non self-aligning rockers, you'll need hardened pushrods and GM guideplates. I went ahead with the chromemoly ones just to be on the safe side.

If you're doing the springs too, make sure you get a good valve spring compressor. A cheap one will cause tons of headaches and waste lots of time.

Here's the instuctions I followed: http://www.streetillusionsracing.com/RR/rr.htm
Good luck.

[DeWynter]

I bought a set of GM LT4 rollers from e-bay (1.6 ratio). The bigger ratio will make your cam have effectivly more lift, or more valve lift for the same cam eg .500 lift @ 1.5 = .533 @ 1.6. The roller rockers I bought fit the LT4 under the valve covers with no mods but I belive the LT4 Valve covers are bit taller than the LT1. When shopping for the rockers you want ones with the narow body to pass the bolts that hold down the valve cover, to wide and the valve cover bolts wont fit. As far as install goes they are pretty simple pull the covers remove olt ones and replace new ones. There is a post on here somwhere that has the procedure for installing them and then tweaking the rockers for valve lash. But I bet Injuneer can tell you the proper steps. Yuo may also need higher lift capable springs depending on the stock rating and what you will get from 1.6 rockers.

Opps I got beat to the answer!

[Craig 94 TA GT]

Actually, you don't really need narrow body ones. I have the CC Pro Mags, which are decently sized, and got them to fit under the stock valve covers. You must "sandwich" the support brackets, where each rocker could touch. But it is recommended never to cut out the support brackets, or you will develop leaks. Here is a pic:

The buttom part of the support is flattened out.
The CC-1305 rockers are standard width, and here is a pic of them completed.

[Z Ya Later]

I remember that night lol. Never thought a valve cover could mask so much noise. Definitely go with some 1.6RRs and follow it up with a reprogramming of your PCM to take full advantage. These will greatly improve the efficiency of your CAI and exhaust (assuming you have done this already).

[redws6]

when i installed RR on a 350tpi, i used air to hold up the valve when i replaced the springs.

[Craig 94 TA GT]

lol Steve, yup, that was a real PITA fiddling with it. I guess all it takes is experience.

Fortunately, on the LT1, the piston can be at TDC, and the valve will not fall into the combustion chamber. So all you have to do is rotate the crank for each cylinder. That probably would save a whole day because I don't even want to imagine removing each plug and putting the compressor for each cylinder in which you change the springs

[redws6]

ill keep that in mind when i do my springs.

[DeWynter]

Well when I got the rockers they werent as "narrow" as I thought. These are the ones I got. Just crane cams rockers I think, with GM badging.

[jerrysta]

I would just like to "bolt in" the new rockers, so can I get a set of self aligning ones for the LT1?

Is there an advantage either way?

[N20LT4Bird]

Ive got the crane gold rollers. They are narrow and fit without mods.

[Nightrage]

What kind of HP/ TQ increase would you see with a swap to 1.6 RR's?

[N20LT4Bird]

I bet you pick up 10-15 HP just on friction loss...not to mention the higher lift of the cam. I have heard numbers in the 30-40 HP range, but thats being really optimistic IMO....

[Injuneer]

I saw a dyno test in a magazine, putting the 1.6's on an engine that was already making a decent bit more than stock HP, and the gain at the flywheel was about 10HP. I'll have to try and find the article. They did a builup that included the SuperRam intake.

I have the CC Pro-Magnums, 1.6 on the intake and 1.55 on the exhuast. The 1.55's are special order. I have the web cut out on one side of each centerbolt support, and have no leaks. I did have to lightly tap the valve covers slightly with a hammer to eliminate a tiny "tap" due to rocker contact.... not sure if that has anything to do with the 0.590" gross lift or not.

[jerrysta]

Are these Ok for a bolt in application?

CC part number 63-1418-16

Magnum Self Aligning Roller Tip Rocker Arms 3/8 stud, 1.6 ratio


Thanks guys