Is it worth the money to buy 1.6 roller rockers and how much hp will my engine gain from it ?
Ive been looking at these from summit racing partnr:CRN-10750-16

 

you have 800 some posts under your belt but you don't know where to post things?

this forum is for nitrous/superchargers/turbos

on that note, make sure you dont' get alumionum roller rockers on a street car. They become brittle and can break under everyday use but work fine for a real race car that gets new things all the time.

The car is stock right?

For the 319 you'd be spending on roller rockers, just get a new cam and you can up duration and lift and get much more power out of your system.

 

some people claim .2 tenths, if you go with them, like nightrider said, don't get aluminum, go with some comp cams magnum steel roller tips, much cheaper.

 

¿Que?

I better not say anything to the 2 sets of aluminum roller rockers that I own with over 150 and 200K miles… or the high mile ones in my brother’s cars or a half dozen others…

I’ve never seen an aluminum roller rocker break without other valvetrain problems (or somewhat related, a monkey behind the wrench used to install them) to cause it.

Not sure that I’ve ever seen the point for something like the magnum, roller tip rockers, unless you’re having oddball geometry problems. Most of the friction in the stock valve train is in the OEM rocker *****, if you’re going to gain anything by adding bearings anywhere the place to do it is the pivot (trunion).

 

The LT4 had aluminium roller rockers from the factory, didn't it? They wuldn't have put them on there if they would cause problems.

 

Then you are the only ones. Aluminum does fatigue. Its not a matter of IF, its a matter of WHEN. It's an unfortunate characteristic of Aluminum. Personally, and dont take offense at this, I dont believe you got 200k on aluminum roller rockers. Not a chance.

 

Yep, there are others also

Believe what you want, but those 2 sets are both on their second engine, and I don't see what I would have to gain by making that up...

 

you just make everything up mark...

track times, what you can do with a stock L98, roller rockers, turbo philosophy....




Still, there must be a reason for why i read what i read and said what i said.

Aluminum does fatigue more than steel, obviously...

 

All sorts of metals work harden, as you flex them the part that is flexing hardens, and when metals harden they get more brittle and are more likely to crack. Aluminum is particularly susceptible.

Aluminum has some other interesting properties. If left alone it normalizes on it’s own slowly. As the temperature that it is at goes up it normalizes faster, about 200-250* is about the optimum temperature for normalizing aluminum. Internal engine oil tends to be hottest around the rocker pivots in an SBC (the reason why you’ll see some valve covers with oil squirters aimed at the rockers) and the bottom of the pistons… funny thing, anyone want to guess about how hot oil gets during hard street use?

Yes, aluminum is softer then steel, so yes, it will eventually deform/wear faster then steel (conveniently, most well designed aluminum rockers have steel inserts at all the points where there is any relative motion), but the fact is that 99% of people never put enough strain on these parts with a street/strip car that it will become a problem in the useful life of the parts, and if you do you’ll be doing things to it that will destroy anything with a stock style pivot ball rocker (or rockers that use the same pivot) much faster.

 

I guess its a slim chance running stock 85-100lbs springs.. I don't know if I'd run alum rockers every day in a car with 140lbs springs.



-- Joe

 

I just thought I should point out, in relation to my earlier post, that there were two corvette recalls during '96 due to rocker arm failures on lt4 cars. However this was due to the roller tips falling out. The second recall only affected cars that were repaired in the first recall.

Ls1 engiines use steel roller rockers, make of that what you will

 

The LS1 alum rockers have the rollers only on the pivot, not the tip. They're 1.7/1 too.
It could be that the tip is the weak link in full roller alum rockers, so the factory decided to play it safe.
There's a thread that showed how to retrofit a set of sbc heads with those rockers. Anyone seen that?

Edit: Found it
https://www.thirdgen.org/techbb2/sho...hlight=tpigirl

 

Wow, everyone is avoiding his original question. To answer the question if they are worth it. Yes.

You can either go with steel or aluminum. IMO, either is fine. Aluminum will fatigue over time faster than the steels will but I don't think it is within anywhere between a 20-40k mile issue.

The steel roller rockers are actually lighter than the alumnums since aluminum is much softer they need to reinfoce it a bit more or add more material, forgot which. By going to 1.6 your adding more lift on your valve train which will result in higher horse power numbers.

You will generally gain about .25-.30 more lift on your cam which and tests have shown adding 1.6 roller rockers on a lt1 equipped forth gen netted a 13rw hp gain. With roller rockers your engine will make a little bit more noise. By going with roller rockers your taking stress off your valve train.

Be sure to get roller rockers with poly locks. They are much easier to install if you adjust your rockers with the engine on.

Pop the valve covers off, take the old rockers off. Put the new rockers on and back the allen screw all the way to the top of the nut. Now tighten the nuts hand tight. Start your engine and go one by one with the rockers and just tighten them hand tight until you don't hear any more clicking. This is Zero-lash.

Once the ticking is gone, add 1/2 or 1/4 turn (depends on your rockers, they should come with instructions on how much to set the pre load to.)

After that, tighten the allen screw in the middle as tight as you can. I used a ratchet attachment. and got that SOB tight as ****. Your good to go. Do not rev past 3000 rpm for the next 40 miles, allow them to set in. After 40 miles, check to see if any came loose (you'll hear ticking, sounds like an exhaust leak).

IMO, roller rockers are a very good investment.

 

Check the clearance on the 1.6 rockers. some have been known to hit even on a stock engine. I've been through this before and got flamed, the bottom line is this, you're already there, just check the clearance and that way you'll know they work.

 

Im not sure on thirdgens but I had to modify my valve covers a little bit. I had to take pliers and straighten out the bridges for them to clear, took about 5 min per valve cover.