mk2vr6t

In the middle of a cam swap. I work on my own cars all the time but I've never owned a pushrod V8 so some of this is new-ish to me. I've done lots of reading on here and ls1tech which has made most of this a breeze so far.

I am buttoning everything back up. I put Cyl #1 to TDC, measured pushrod length, added .050" for preload, bought the appropriate sized pushrods, (7.375 in my case), and installed them. After torqueing and checking everythhing, i began turning the motor over. Everything seemed to go smoothly and all the valves opened and shut. after turning it over by hand several times, i went to go check the torque settings again, and noticed that the rockers have some movement when the valve is fully closed.

I looked a bit closer and removed the rockers, and noticed that the pushrod itself, when pushed down, feels springy. I assume this is the lifter, and i assumed its that they have been compressed after i added the pushrods and have no oil in the system (replaced oil pump and timing chain). I added the long 7.425 pushrods i had lying around and the rockers still had this movement which made me rule out the preload issue. see the video below. Let me know if this seems most normal to everyone (rockers are torqued to 22ftlbs here)



The other thing I have a question about - timing chain.

I chose to upgrade to a C5R timing chain and a melling pump. I intended to add in a new damper but my stock one seemed decent enough. only a little scraping on it. When turning the engine over by hand, the chain drags along the plastic damper a bit. Enough to make some noise. I didnt check the stock chain setup before removal to know if this is normal or not. Again, i figured the centrifugal force of the engine running is going to push that chain "out" while rotating and probably not come into much contact with the damper except for when getting on or off the throttle fast.



If anyone could let me know if this is all normal or what i expect it to be to put my mind at ease, or let me know if theres a bigger problem before i fire it up, that would be great.

Thanks,

LS1MCSS

iTrader: (18)

That's pretty much normal for the rockers. There's no oil pressure against them right now. When the motor has oil pressure, they won't be like that. As for the chain guide, I have never used that type so I can't really say much about it.

Iam Broke

I agree it's normal on the rockers, had the same happen when I upgraded springs, rockers & trunions.

Pseudonym

iTrader: (3)

In some pictures, it looks like the timing chain would rub the damper. I would pull it out to see if it has any wear marks. Im also using a different type of chain guide, so I dont know how normal it is. Rockers are fine though.

mk2vr6t

The guys over at ls1gto.com are telling me its wrong, yet I have double checked everything and it seems to be that after 3-4 turns of the motor, the load from the springs opening/closing the valves has compressed the lifters and squeezed the oil out, now leaving it "springy".

If my lash and preload calcs were off, I believe once the lifters compressed, there would actually be some dead space between the valve and the rocker. There isn't, its just that the pushrod can be compressed now.

Maybe I am missing something but I feel like all that is happening is the lifters have now been compressed.

BFASTNOTLAST

Use the EOIC method for measuring pushrod length from 0 lash, you won't go wrong... Don't sweat the plunger depressing.

mk2vr6t

So I'll check it again, using the EOIC method to check that I'm on the base circle. and I don't need to worry about the lifter depressing as long as I don't depress it while taking the measurement, correct?

But if I measure and check everything again and it all seems normal, the lifter depressing and springing back up as shown in the video is normal?