I have some actual LT4 rockers from a 96 Corvette on my 91 Corvette L98. The actual LT4 rockers use 10 MM studs and nuts, and are not adjustable; as opposed to the GMPP LT4 rockers that use a 3/8 adjustable nut and stud. The stud and nuts are designed to bottom out at the appropriate valve lash. Well, with the nuts bottomed out on my L98, they are hanging the valves open. I can back them off about 2 turns and the engine runs great, but I know the nuts won't stay put without any kind of locking device.

I can think of 2 solutions:

Shim the rocker stud out from the head. That will raise the rocker, and if the shim was the proper thickness, bottoming out the nut on the stud could yield the proper valve lash.

Or...

Tap the nuts for a 10 MM allen style plug and make them adjustable. The nuts right now are a 10 MM fine thread about 2/3 of the way through, then there is just a 1/8 inch hole the rest of the way through. I could conceivably drill and tap that hole to match the 10 MM threads within the rest of the nut, effectively threading them all the way from top to bottom. Then I could get some 10 MM fine allen head plugs and use those to lock the nuts down.

Any thoughts or other ideas?

 

I know this isn't what you're wanting to hear, what with all this "actual" and "Corvette" stuff; but...

How about, put the right hardware back on the heads, and just get some rockers that fit? Forget graunching on those others that don't fit or work right.

Sometimes all the romantic- and impressive-sounding buzzwords in the world don't make a car run better.

 

I have these, and I can't afford another set. It'll take me forever to sell these, and then find a deal on the proper stuff. I don't have a bottomless pit from which to pull cash to mod the car, so I am forced to work with what I have.

Of course, if you wanted to donate the correct, non-fancy sounding stuff, I am all for it. A cash donation would be welcome as well.

 

Are those other choices "free" or even cheaper than, say, a set of Comp 1400 series rockers?

How much do bus tickets and tow charges cost in the meantime?

How much money is tied up in the car and all those other mods? I have beyond a merely "hard" time believing that there's any economic hardship involved in this decision making process.

You've got a hodgepodge of stuff that doesn't fit and doesn't work and even if it did, wouldn't offer any benefit at all over just about anything else you could put there. Sounds to me like it's a whole bunch of effort to perpetuate a bunch of nothing. You'll be ahead at least in time, trouble, and use of the vehicle, to just quit monkeying around with all that buzzword stuff (no matter how cool the buzzwords are), cut your losses, and do it the commonsensical way.

Some things are worth experimenting with to perfect; then there are the other kind of things. I believe this falls into that "other" class.

 

How much is a set of 1400 series comp rockers? The LT4 rockers were what I had, and they were free.

I have a 92 Pontiac grand prix that I drive daily, so there are usually no bus tickets. The Grand Prix does break down on occasion, I would estimate $150 a year on tow bills. On the days the Prix is broken, I can usually bum a ride, but there is the occasional bus ride, I would estimate $25 a year on bus fare. The total for the bus rides and tow bills, for one year, comes to an estimated $175. What does that have to do with my rockers?

I guess your point is that after 1 year, I could have nearly bought a set of 1.6 roller rockers with tow bills and bus fare. I'd really rather not wait a year if 20 hours or so of my time can get my set-up going. Right now I am low on cash and time, but I have more free time than cash. Some elbow grease and a little garage engineering really don't deter me from trying to make this work.

I bought the car for 9.5k, (I still owe on it) and have about $3500 in the mods in my sig. The lions share of the mod money is in the clutch and drive train. There are really no suitable clutches out there for a ZF6 transmission if you plan to abuse the car at the drag strip. The McLeod is the only one that has a solid track record, and you pay out the *** for it. The cryo treated parts are all from DEEP FREEZE CRYOGENICS, LLC 1.866.324.CRYO. I bought those after I broke a spindle at the drag strip.

You really don't know **** about my financial situation, but apparently you won't try to help me unless you have the full back story. I am recently divorced, and still trying to financially recover from that. I wasn't well off or anything before the divorce, but I could of swung a $200 set of rockers on payday if I really wanted to. That just isn't an option right now. These rockers were given to me by a friend with a 96 Collectors edition Corvette. My owning of them has nothing to do with catch phrases, fancy words, or anything else. They were free, and I am down on my luck right now. Now that you have all the back story, maybe you could offer some assistance?

I already said the 'buzzword' had nothing to do with my owning the rockers. I was just trying to get some more power on a slim budget. The LT4 rockers are identical to the Crane 1.6 roller rockers with the exception of trunnion size, and the LT4 valve springs I got with them should work well with these rockers and the stock cam. I really don't see how it's a mismatched set-up in terms of components. Other than the lock nut issue, they should be no different, and provide the same benefit as any other 1.6 roller rocker. Am I wrong?

Great, you don't know anyway to make it work. You replied twice, insulted me by calling me a liar, and didn't help at all. Thanks man, keep up the good work.

I'm sorry to come off like an A-hole, but telling me to buy other stuff, when I specifically asked for a way to make what I had work shows an extreme disrespect for me. If you think I should buy other parts, thats fine, but at least have the courtesy/decency to try to help with the original problem. Assuming that because I have a Corvette with a high dollar drive train, and have 'real LT4 rockers' that money is no problem for me is really rude in my opinion.

I'm asking for a little help is all. Not someone to call me a liar and tell me to buy stuff that I can't afford right now.

 

Oooops.... I must have touched some kind of a nerve somewhere.... sorry.

COMP Cams Magnum Steel Roller Tip Rockers: CCA-1412-16 - summitracing.com

Enjoy!!!

 

The rockers I have now are a full roller 1.6, as opposed to the roller tip 1.5's you posted a link to. I would think my current rockers are a vast improvement over the rockers you posted.

You did touch a nerve. You indirectly called me a liar, assumed **** about me, and kinda pushed me into bringing up my favorite subject, my recent divorce. It's not a great way to make friends, but maybe I am 'so ****ing dumb' you don't care.

Anyway, thanks for the information, I'll look elsewhere I guess for a way to make these work.

 

In theory, it sounds like it'd work. It doesn't work right now, and the worst thing you could do is make it not work some more, right? You said it'd take forever to get rid of the rockers if you wanted to, and they were free, and would only hold value to someone with an LT4 vette, so you might as well try. If you wanted to keep the rockers in perfect condition, I'd say go with your shim idea. The tapping way sounds more questionable. You know that the shim and all that would hold, at least until you can afford the proper parts.

Just my $.02

 

Do the LT4 nuts fit the rocker studs in your L98 heads?
If not perhaps you could buy lock nuts for the studs.
BTW were here to help not bash!

 

Sofakingdom is set in his ways, and thats just how it is.

Personally, i'd get different rockers too - but I remember a point in my life where I had no choice but to use what I had.

If the LT4 is designed for the rocker to "bottom out" (like a non adjustable rcoker) I suggest you shim the stud in the same manner as the LT4 is done. Of course, your gonna need to be within .001" to maintain propper lifter preload.

Good luck!

-- Joe