redbird555

iTrader: (14)

I did a head gasket and lifter job on my car a while back but I have aquestion on something I mighta screwed up lol. I needless to say took the heads off had the valves reseated and new seals put in. I put everything back together and torqued the rocker arm bolts over two passes to 24 ft lbs. Question is should I have rotated the engine to tdc for the first cylinder then do the second etc? Ive heard this from a few people but Ive also heard there was no need to because the heads were off and all the valves closed. Is this correct? The stupid part is I didnt use loctite on the bolts which I kick myself in the *** for. I cant hear any valvetrain noise by ear except for the piston slap lol. Ive used a mechanics stethesccope and taken the filler cap off to listen up close and everything sounds smooth. I think if my valves were misadjusted I'd hear them slapping as I revved the motor whereas the piston slap goes away immediatley after 1200 rpms.
Thanks Dan-

JPH

iTrader: (2)

Aslong as they are ALL torqued to 22ft. lbs, then you are good to go. But it wouldn't hurt to double check them and make sure there not on the opening/closing sides when your confirming that.

redbird555

iTrader: (14)

I'll check it out but yup I watched all the springs compress as I tightened them. Everything went to twenty then 22 and then another slight twitch just to make sure... Motor runs fine with regular trips to the redline without issues and there seems to be no valetrain noise. Just to be sure if valves are misadjusted they tend to get louder as the engines revved due to them being slapped by the rocker correct?

JPH

iTrader: (2)

Honestly, its really hard to misadjust a rocker that gets bolted down to a certain spec. But improper selection of pushrods, etc.. can lead to that, or just flatass not knowing what your doing also. LOL But I think your good to go man.

redbird555

iTrader: (14)

Ya thats what I was thinking it torques to 22lb no adjustment its there when its there lol. And the fact the cars been fine for 2k miles i think im good

redbird555

iTrader: (14)

just wanna clear another thing up if the rocker arms were not torqued to specs would there be chattering coming from the covers and would there be a power loss considering the valves wouldnt be reaching max lift

bearcatt

iTrader: (41)

Check out this thread. This is the correct procedure.
https://ls1tech.com/forums/generatio...ll-advice.html




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redbird555

iTrader: (14)

Hmm I didnt do that but wouldnt it be noticeable if something was screwed up

S10xGN

iTrader: (11)

You'd know pretty quick when the threads pull out of the head...

bearcatt

iTrader: (41)

Depending on the valve springs, the cam, type of rocker arms, that can have an effect on a valvetrain setup.

Alot of guys never do any sequence, they just tighten everything up.
At least you made a couple passes. If you're unsure, it won't hurt to pull the vavle covers off and double check.

I learned the hardway. Do not use lock-tite. I ended up breaking of a rocker bolt from using lock-tite. If I was going to use anything, I would use anti-seize. I say it's best not to use anything. The main thing in to keep the rocker bolt hole threads and rocker bolts clean.

Also, setting up your preload right the first time helps. The less you have to put together and take things apart, the better off, you will be. No need to fatigue and wear out the rocker bolts and threads.

If you're having no problems, you're most likely fine.




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bearcatt

iTrader: (41)

That's for sure.



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redbird555

iTrader: (14)

Ya and that hasnt happened yet. It just got me wondering because piston slap has seemed to be a little louder and I was wondering if it could be from the valvetrain too but iI could prolly use an oil change soo... Like i said though valvetrain listening with a stethescope and ear is quiet so I think I'm good. But lemme get something something straight as I'm 18 so I wanna make sure I got this right. The reason one would normally follow the tdc procedure is to make sure everything torques correctly? Which in this case I torqued it twice and each spring did compress a bit and once they were compressed in matching to their lifter the bolts tightened and it torqued to the desired spec. So in this case I should be good if it hasnt blown in 2000 mi. Would that procedure in torquing have any decrease on power if the valves arent opening all the way in which case would you notice the motor missing or running poorly?

redbird555

iTrader: (14)

btw thanks for the replies i just wanna make sure i get this right

redbird555

iTrader: (14)

also the valve train went back together 100% original except for new lifters

redbird555

iTrader: (14)

preload i think was fine seeing as the pushrod length didnt change nor the cam

bearcatt

iTrader: (41)

If your pushrods are to short, you will hear it very loudly. So you don't have to worry about not opening the valves all the way.

If they are to long, it will hold the valves open and the car will miss and be hard to start. If it's a little more than stock preload, you may be stressing the lifters a little bit more than normal.

Another thing to understand about these LS1s is that they expand about .010 of an inch when they get hot, thus giving you a little less preload.

You see the main thing about following sequence is to get the cam on base circle so you're not putting any pressure on the lifter and pushrod. This puts less stress on the rocker bolt threads and doesn't require such extreme valve spring compression like when the cam is at max lift.

If you made two passes, the lifter probably bled down completely on the second pass.

Rod knock seems to be common for these cars when they are cold.
Mine had it but once I decarbonized and cleaned the pistons, it went away.


See below.

The LS1 lifters vs new LS1,LS7 replacement lifters have a plunger depth that's about .050 higher. The one on the left in the LS1,LS7 replacement lifter. My 2000 Firebird had the newer style LS1,LS7 style lifters.

Another factor is head gasket thickness. My original head gasket had a very thin graphite gasket. My new head gasket is a GM MLS that is at least .010 thicker.

If you had the old style LS1 one lifters... ( the ones on the right ) and replaced them with the the newer LS1,LS7 lifters, you may have more preload than normal.

The lifter on the left is the newer LS1,LS7 style.






Alway glad to help.


About your oil changes ...

Blackstone Labs and Dyson Labs have shown the best oils for our LS1s are:
( time and time again )
Pennsoil Platinum Plus Synthetic, German Castrol Syntec or Amsoil.
Forget about ball bearing commercials. That's BS.
Sarge over on LS1.com is one of the most informed oil guys around in the LS1 community,
he knows his stuff. You can't dispute science.

One last thing, the best way to really check preload is
1.) Put #1 at TDC.
2.) Use a Comp pushrod checker.
3.) Figure you pushrod length plus about .080 preload for GM lifters.

With all the above said, chances are, you are ok.


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vettenuts

iTrader: (4)

Here's a quick overview. When you tighten the bolt, you are basically stretching a spring. The amount of stretch in the bolt (along with a few other things) determines the amount of load the joint will take before the joint separates. With the rocker arms, the torque wrench is the tool that is telling you when the stretch is correct. The torque measurement is completely based on the friction in the threads. Now look at two case, one where the lifter is down on the cam base circle and the valve closed and one where the lifter is up on the top of the cam lobe and the valve is open. The valve open case requires that you tighten the bolt and compress the valve spring. This puts a lot of load on the bolt and threads, providing much higher friction so when your torque wrench clicks the actual bolt stretch is partially based on the forces required to overcome the valve spring. The bolt may be tight but the joint preload is not correct and less force will be required to separate the joint.

I have seen guys say I checked them and they were still at the correct torque. Actually, once the bolt stops moving then using a torque wrench to check the torque value doesn't work because there are two types of friction, static and dynamic. When you are tightening the bolt and it is turning, dynamic friction is determining the torque measurement (sometimes called running torque). Static friction is much higher, especially on a dry steel/aluminum joint so when you put the torque wrench on a bolt it takes a lot more torque to break it free. This does not mean the joint is properly preloaded. The only way to verify the torque is to first back the bolt off 1/2 turn and then re-tighten with the torque wrench.

redbird555

iTrader: (14)

Thanks everyone ya I went with stock lifters as I didnt really look into the ls7 so I think I'm good but ill be home in a month so I'll take the valve covers off and retorque aeverything one more time.

redbird555

iTrader: (14)

I had soe free time today so I decided to take a quick peak at the vlaves... I got the motor as close to tdc as I could by eyeballing the valve as I didnt have anyone around to wath it as i wrenched the crank. Torqued the bolts in sequence then turned the crank 180 degrees checked everything then rotated it another 180 and torqued the other bolts. No bolts needed to be retorqued so I should be golden lol

bearcatt

iTrader: (41)

I think you'll be fine.


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