Hello again, I've run into another snag, here is some detail. Plz be kind. First time.
1995 Corvette LT1
Parts related to the valve train, Lloyd Elliot LE1 ported heads and manifold, they're a great condition 94 heads I had bought to send him. Comp Cam 218/224 .571/.566 111 from him, heads have another set of springs. Scorpion 1.6 Self Aligning Roller Rockers Narrow Body, LS7 Lifters, 3/8 studs, 7.200-7.195 stock length hardened push rods just for the heck of it...
I'm certain my timing is correct but cover is on and I just sealed it along with the one piece oil pan I'd have to drop to take a look. Okay I remember I started when the timing gears were set to 12oclock and 6oclock perfectly straight dots next to each other. I removed the top locking threaded pieces of the rockers nuts before starting. As soon as I had set 0 lash on all rods and go to turn the engine 90 degrees, I can only turn the engine barely at all before it gets hard and a few rods are pressed well into the lifters. so I unloaded those lifters by loosening the nut and continue my 90 degree turn, but it takes like 2 or 3 times were they keep getting pressed into lifters before I can complete my 90 rotation, I've turned the motor maybe 8 - 10 COMPLETE times by now and I feel like I'm going in circles. Its gotten a bit better now, more and more lifter's are setting at 0 lash no tightness at all - just right, but still different lifters keep getting loaded by the rods, after I fix those and keep rotating, different lifters keep taking their place until I feel like I've gone all around again and going back to adjust the same ones over.

What am I doing wrong? Are my rods too long? Too short? Head gaskets don't seem any thicker at all from the ones I replaced, the cam isn't so huge I've heard people going with 7.180 rods or something with bigger cam and non self aligning rockers. could it be that the timing is somehow way off now? Even though after installing everything I turned the engine multiple times and the timing would always come back to true before I sealed it all with cover, pan. Could it be that Lloyd accidentally made a boo-boo with the valves when he installed the springs? I've never used a length checker but maybe I should give it a try? Maybe this cam and with those Scorpion rockers it made enough of a difference for rod length?

 

I'm starting to suspect that I need two different rod lengths. I guess I should buy an adjustable rod measure tool? I need to learn to use it too.

 

Make sure that you aren't bottoming the plungers within the lifters ... it real easy to do that with hydraulics ... don't let the pushrod cup gap at the snap ring ... in other words , you should get to zero lash without pushing the pushrod cup and plunger down and away from the snap ring in the lifter ... don't spin the pushrod , rather shake it up and down to arrive at zero lash . The internal spring in the lifter is not very stiff and will let you bottom the plungers while allowing the pushrods to freely spin between your fingers .

 

In the pic of the rocker arms on the engine, is that with them adjusted? Those Allen set screws should be well into the nut. In those pice it looks like they are barely engaging the threads.
As far as pushrod length im not an lt1 expert. But from your combo it seems they should be stock length and go from there. Adjustable rods are cheap and easy to use but you should also use a checking spring with them as well. So now you'd have to take out a spring or 2 and replace them with the checker springs.
If it feels like something is binding, it probably is.. trust your gut on that one and double check everything.

 

Woah idk if I trust myself with removing a spring. I just left those threaded in a bit on that pic, I took them off later and I'll lock them in place after it's all complete and preloaded. Maybe I should get an adjustable rod but from what I read, I see that the stock length should work. Haven't been able to get them down. I could leave them all at 0 lash real nice, but then when I go to spin the motor just a bit- a few rods push hard into the lifters over and over again, eventually I'll get it down but then another set of Lifters begin to do the same. After setting multiple times they start to come around again. So confused, never heard of anyone backing out the nuts while they're adjusting, I only ever see them spin the motor and they keep tightening. Me, I tighten some and loosen some dang plungers too.

 

You are only adjusting/tightening the rockers on the cylinders while that cylinder is at TDC and not all cylinders at once, correct?

 

Thx, I do take my time on tightening the rockers while I'm spinning the rods & moving up and down too. I set it where I could barely feel any drag at all, visually the lifter isn't slightly pushed in either. So after I set it all on 0 and go to spin the engine, I can just barely turn a bit before a few select lifters are pretty much bottomed out. After getting those right, it seems more lifters are starting to do the same as the cam is coming around. I'm not sure if this is something that happens with even ill fitted rod's?

 

I'm doing it a more simple way, all at once. I happened to be at both gear dots pointing together when I started.
I've seen folks do it on any engine position, 0 lashing everything as soon as they assemble the parts, they go to turn the engine and get some loose ones again, so they tighten. After 2 full revs on the cam they're all done. Simple
not working out for me though

 

You filled the lifters with oil, right ? You need to go ONE CYLINDER AT A TIME. Rotate the engine back and forth and find the spot where either direction the pushrod starts to push the rocker and take the clearance out, then do the same with the other valve on the same cylinder, then move on to the next.

 

Think you adjusted those wrong the engine should be easy to turn over.
If you can remove plugs then start at Cyl 1 and use the EOIC method one valve at a time. It will take longer but is foolproof.
https://www.motortrend.com/how-to/ccrp-0702-camshaft/
you can look this up on youtube also...there is an easier method but for starters this will get your right. 3/4 turn past no more up/down slack btw

 

https://www.summitracing.com/search/...rder=Ascending

I used on of these to get the length just right. Then I ordered the correct length rods. Mark the top of the valve with some type of marker so you can see if the rocker is bearing on one side of the valve stem or the other. You want it right in the middle in order to prevent valve guide wear.

 

^^^ This ^^^

You can only set the lash when a lifter is on the base circle of the cam. You do them all at once and some of them are going to be on the base circle and some are going to be on the cam lobes. Then you rotate the engine and some of the lifters that were (correctly) on the base circle are going to start on the lobe ramps and open their valves. Look on youtube, there's a ton of how-to videos.

GM Small Block Valve Adjustment Procedure

 

That only works on LS style setups that are non-adjustable. Trying that on an adjustable valvetrain is a recipe for valve to piston contact and the ensuing carnage that causes.

You can lash them with only 2 turns of the crank - start at #1 or #6 tdc.

Get #1 to Top Dead Center, set lash on:

Exhaust: 1, 3, 4, 8
Intake: 1, 2, 5, 7
​
Get #6 to Top Dead Center, set lash on:

Exhaust: 2, 5, 6, 7
Intake: 3, 4, 6, 8

The best way to check sweep on the valve stem tips is with a blocked lifter, a test spring and yes, an adjustable pushrod. Lloyd typically installs .100" taller Manley valves when he works on these heads. This will push the sweep range toward the outer 1/3 of the valve stem with stock 7.2" pushrods. I destroyed my valve guides running this kind of setup, and wasn't happy running them centered with a much shorter pushrod. I hope you have a better outcome.

Edit: Also, you didn't mention what kind of timing set you're running but it looks like the crank sprocket is cut with three different keyways. If you don't have the right "dots" lining up, you could have your cam way out of time with the crank, which is also a recipe for valve to piston contact. If I were you, I'd pull the timing cover and be sure of what you have.

 

As spfautsch says. This is the way I did it many miles ago and all is perfect. LE did a great job on the porting and I have a strong running LT4.

 

Good replies, thank you all! I'll be trying another method as mentioned here. I've seen a vid of this method I was using on an LT1, but the guy had non self aligning rockers and guidplates, which I don't use. Maybe that matters.
I'll see if I can do some work on her and post results!

 

I bet it runs just fine when youre done

 

The more I re-read the thread, the more I think he better make sure his cam isn't installed way out of time. My little brother once installed an adjustable timing set using the wrong dots and ended up with the cam 120 degrees out of phase with the crank. The result was valves leaving witness marks in the forged pistons that slammed into them.

P.S. - Everything on YouTube is not necessarily the gospel truth. The guy in the first video is a blithering idiot.

 

I thought I had a pic of the new timing set up, but no this is the closest one I got. It's hard to see the crank gear, it's discolored because I heated it up just a bit for it to slide in, but that white mark is 0 degrees, checked 3 times. You can also see the cam at the 3oclock position ready to accept the gear & chain. And dots were centered perfectly when I finished, we turned the crank probably twice 360 and it came back lined up both checking 180 and 360. So maybe it's not out of time, I'll see if I can check with a flashlight in the cover to see the timing lol!
I'm going out now to try this again. Restarting

 

Yep, not possible to see timing looking down the seals of the cover -_-

 

Your cam dowel does look like it's in the right location, but that doesn't mean it wasn't turned in order to install the cam gear. If memory serves, those type of sets use a circle for 0* cam timing, and a triangle and square for advanced / retarded. As long as you used the circle on both you're golden. If the symbols got mixed up you're probably experiencing VTP interference when you turn the engine over with the valvetrain adjusted.

You can check that cam timing is in the ballpark by removing all the pushrods and setting the crank at TDC. If you're on #1 TDC the #6 intake and exhaust lifters should both be off the base circle. If you're on #6 TDC the same should happen with the #1 lifters. Just watch them as you rotate through TDC - exhaust should be closing and intake should be opening on the cylinder that's 360* (crank) / 180* (cam) off TDC.

If you adjust lifter preload like I mentioned earlier and everything moves, you're likely just experiencing the load of the valvesprings that makes it difficult to turn. If you have the spark plugs in it'll be even more difficult because you'll be fighting compression. Also, it's normal for the lifters to bottom out like you describe - the valvesprings are simply overcoming the plunger spring in the lifter. That will go away when you have oil pressure.

So is that an LT4 intake?