Hello all, I picked up a set of Elgin stock replacement rockers and a set of Comp Cams 7.2 inch pushrods and I was wondering how to install them properly. I saw a video featuring a 1976 Camaro, but I need a guide for a 1988 Corvette. The roller cam and hydraulic lifters make the sequence different from the 76 Camaro in the video, so if anyone knows the proper sequence for it I’d really appreciate the help. Thanks!

 

Well no its not done differently providing the Camaro had a Hyd Cam. Those Rockers are not going to fit under your Stock Valve covers. You probably do not need to change the Push Rods.

 

I probably should have prefaced the OP by saying I don't know anything about the engine, it could be a different cam for all I know. I did head gaskets and that's as far as my dad would let me go with it. The rockers are the same as stock for my 88' L98 and the old pushrods were rusted (I'm thinking due to bad intake manifold gaskets.) If you know the proper sequence or even torque specs (if applicable) please let me know.

 

How many pushrods were rusted and how badly were they rusted?

 

I think You need to watch a Video on how to adjust Valves on a SBC. And or read a shop manual. The Rocker Arms are not torqued to a spec depending on what Cam is in it. Its all interesting stuff to learn and well worth the time.

 

I think all of them. Not sure because I threw them away about a month ago (not the smartest move.) It was only the tops and bottoms though, not on the sections that contacted the lifter and arm, and not in the center.

 

Reading a shop manual was my initial plan, but the only thing I could find regarding rockers in the Haynes Manual was that they were to be tightened in a specific order. I was surprised to see that there wasn’t any other information on them in the manual.

 

Did you tear the engine completely apart to check for possible water damage on they internals, i.e. the bearings.... Because you could be replacing top end parts and have a bad bottom end. Push rods dont just rust unless moisture has penetrated your engine.

 

It sounds as though your shop manual is referring to some but not all factory rocker arms that are non adjustable. In this case then yes they would just be torque'd in place. Nearly all after market Rockers are adjustable and the process is done differently depending on whether you have a solid lifter or Hyd cam. I doubt you have a solid lifter cam.

 

Yes and no, down to the block for a head gasket job is the furthest I got. The cylinders were full of coolant so that was a big indicator that something was very wrong. Got the heads machined and a crack near the driver's side center head bolt hole welded shut. I plan to have this engine run until I have the money to build a solid 383 with a TPiS Mini Ram and all the works. I'd just like to do this right so the engine doesn't implode once I'm done.

 

Would my stock replacement rockers need to be tightened following the firing order? The video I saw showed that it needed to be done in the firing order while wiggling the rods until they no longer move, nothing was mentioned about a torque value for the arms. Unfortunately, there is another L98 (a 6.0L 4th gen aluminum block LS from Australia produced from 2006-2010) that comes up in place of the 5.7L L98 in corvettes, trucks, camaros, and firebirds of the 80s when searching for a valve adjustment on an L98.

 

It's a small block Chevy with hydraulic lifters. It's just like 34 million other small block Chevys with hydraulic lifters. Watch some yootoob videos and don't overthink it. There is absolutely nothing different about the order of operations to adjust the valves on the L98 versus any other small block Chevy.

 

I would change the above word " tightened " to "adjusted". You started out with Elgin aftermarket Rockers and now you are using Stock Replacement Rockers ? Just forget the whole Torque Value idea. There has got to be many many videos on adjusting Rockers on SBC's don't bother looking at LS engines or any other engine even though they are pretty much all done the same. The Nuts that Adjust the Rockers are an intertfearance fit. In other words they are a form of a lock nut. The factory uses them because they are cheap. If you were to screw 13 of them on a Rocker Stud you would find that they are all differ a bit in the amount of torque to put them on. This is why a Torque Value has nothing to do with this. Most people just throw away the stock Nuts and go with aftermarket Nuts that have a Set Screw to lock them in place. No ware in the process is a Torque Wrench used in adjusting Rockers.

 

Being a first-timer is a bit difficult so please excuse my stupidity.This was the set I bought, the pushrods were too long that’s why I got the Comp Cams 7.2s. They are stock replacements, sorry if that wasn’t clear. I wasn’t sure if the sequence was any different from other sbcs or if there was a certain way to do it on Corvettes. Thanks for the help!

 

We don't fault you for being new - actually we love to see young people not afraid to dive in and fix their own stuff!

How did you determine the pushrods were too long? It looks to me like anything other than factory stock length is going to mess up your geometry with all the other parts being factory spec. The only difference might be in pushrod lengths between hydraulic roller and hydraulic flat tappet lifters.

In adjusting hydraulic lifters on any SBC (doesn't matter if hydraulic roller or hydraulic flat tappet), the basic idea is to rotate the engine to such a point where the cam lobe is all the way down for that valve. Then you adjust it to zero lash by tightening the rocker arm nut. You can tell zero lash by feel, because you need to rotate the pushrod with one hand as you're tightening the nut with the other. As soon as it becomes difficult to turn, you're at or just a little tighter than zero lash. Once you get zero lash, then you just tighten the nut down another turn or 2 (I don't remember the spec off the top of my head) to set the lifter preload. The idea here is to basically put the little plunger inside the lifter in the middle of its range of travel. Too tight and you get solid lifters. Too loose and you get valve lash/noise/loss of performance. Do report back and tell us how you made out with the project!

 

Thank you! I’ll let everyone know when it’s all back together and running! The reason I knew tge rods were too long was because the rockers sat so high that I couldn’t even set the nut on the stud. I had some pictures of the valve-train from when it was still together and knew they were way too long.

 

I'm guessing the pushrods included in the kit were for flat tappet lifters. The lifter bodies of roller lifters are longer, so they require shorter pushrods.

To expound upon my last post, don't get hung up on what valves to adjust when the crank is in this position or that or the other. Shop manuals can be very confusing and make you lose sight of what you're actually trying to accomplish. Read my last post carefully. That is what you're trying to accomplish for each valve, and it makes no difference at all in which order you adjust the valves.

By the way, I graduated from high school in 1988, and my second Corvette was a 1988 black on tan Z52 auto coupe. The first Corvette I ever got to ride in was a 1988 35th Anniversary edition. So I love 1988s!

 

Yes those pushrods were for flat tappet cams. Thank you so much for the help! It seems at times like there isn’t any information out there on 88s so this forum is a great help!