Let me make this much more simple than what I was just about to write.

I need to check for broken valve springs, bent/broken push rods.

I've read the ls1howto guide for installing a heads/cam package but I've got more specific questions regarding the proceedures for doing a job that's much less sophisticated.

I want to inspect each pushrod and do a compression test for each cyl. to make sure I dont' have any bent valves.

The pushrods come out once I take the rocker arm off. Is it literally as easy as removing the bolt from the rocker arm, pulling the push rod out, inspecting it, and putting it back in and bolt her back up?

My friend said that it's going to be a pain in the *** if I remove all the rocker arms because we'll have to remeasure to make sure valves don't hit the pistons. I'm not doing a cam swap here, i'm simply unbolting and rebolting a resting car.

From the readings, nothing indicated this and I feel like he might not be on the same page as me. But since I didn't go to a technical school (which doesn't mean jack sh** to me by the way) he feels I have no clue what I'm talking about.

I'm not taking the valves out, as I'd rather give it to a shop at that point. I just wanted to inspect the pushrods for bends. My buddy suggested inspecting them before removing any of the rocker arms (duh) but if there's a slight bend in one we might not be able to see it clear as day.

Edit: I DID plan on turning the motor over by hand a few times once i tightened everything back up to make sure everything 're-situates' itself before starting the motor. Then checking again to make sure everything is torqed to spec.

I'm just concerned that if I remove the rockers, the valves might move and and cause a catastrophe.

 

pull them as you have outlined and if not bent reinstall and follow tq procedure for rockers. the LS1 rockers do not require adjusting like older rocker arms, so if they are correct now and you do not replace anything you are good to go.

If you have bent parts I would check the new parts on install.

More Than Zero

BTW Bottom line is that your friend is thinking about rocker arms with adjustments that need to be measured on install.

 

he's saying each cyl has to be set to top dead center before we take each rocker arm off and mess with the rods/valves and is worried about firing order. I'm so lost.

 

Some people say it's best to set the valve lash with the engine at TDC and some say it doesn't matter on the LS1s just torque the rocker to 22lbs and you're good to go. I don't know which is the best, but if you want to go to TDC for the replacements...

Pull the plugs
Use a small aluminum or plastic rod to determine when #1 is at TDC
(This is close enough for what you're doing)
R&R the push rods on cylinders #1 and #6
Rotate the crank 90 degrees clockwise (3 o'clock)
R&R the push rods on cylinders #8 and #5
Rotate the crank another 90 degrees clockwise (6 o'clock)
R&R the push rods on cylinders #4 and #7
Rotate the crank another 90 degrees clockwise (9 o'clock)
R&R the push rods on cylinders #3 and #2
Button her back up.

If you're really worried about your pushrods and are going to go through this much work anyway, why not buy a set of aftermarket (Comp Cams High Tech for instance) 7.4 pushrods for $100 and stick them in while you're at it. Push rods are a weak link on the LS1 and replacing them is a good idea anyway.

 

He's used to working on foxbody mustangs, not corvettes mind you.

 

pull rockers, then take them out. that easy

 

Man, quit listening to that friend. When you loosen the rocker arm bolts, it will allow any open valve to close (becaues of spring pressure). Go ahead and loosen all the rocker arms, pull the pushrods, and check them. It helps to roll them on a flat table or piece of glass to see if their are even slightly bent. Like it was said earlier, when you reinstall the rockers, just torque them to spec. It doesn't matter on an LS motor if you are at TDC or even if the valve is open.

Tell your "friend" to do some reading on LS1Tech.com and get up speed with the Gen III engines.

 

Owned! I love you guys!

 

Don't worry about piston position. You aren't changing the cam timing. Unbolt the rockers, check the PR's put them back in the same hole you took them from and torque the rocker back down.

 

Your friend is incorrect.

1. Remove misc **** per ls1howto.com to get to the valve covers
2. Remove valve covers (aka rocker covers)
3. Remove all rocker arms, just loosen bolt and remove.
**Keep rockers in order that they came off, I marked a baking pan and laid them in there. When you re-install it's best to put them back where they came off.


4. Simply pull out pushrods and check them for straightness, put them pack in where they came out. If bent replace.
5. Inspect all springs for cracks/breakage. If any broken I'd replace the set. You can get '02-'04 Z06 springs (aka yellows) for $55 a set from www.gmpartshouse.com or www.fredbeansparts.com
6. Put it back together
7. Torque rocker arm bolts to 22 ft/lbs.
8. Turn the motor over a few times and re-check for good measure.

**You need a pretty funky wrench to get to the crank bolt w/ the steering racin in place... so I had the car all the way up on jack stands. With the car in gear just have someone rotate the back wheels forward... the motor will turn over

 

Wow, awesome. Thanks for the advice!

 

^ No problem... that's what we're here for. Let us know how it goes.

 

He still thinks TDC is required. He's going to sign up and voice his concerns since i don't know precisely how to say what he's saying.

 

Your friend is correct, here is the correct install. Removal is reverse (loosen instead of tighten). You don't have to do one cylinder at a time with stock rockers, you do if you have Yella Terra's or other shared shaft rockers.

 

I disagree... as with any oem procedure there are short cuts. As you tighten the rocker arm bolt it will compress the spring as needed.

This is why you rotate the motor a few times then re-check the torque. I use a dab of blue loc-tite on the rocker bolts. I've never heard of anyone having any issues.

 

When I installed my Yella terras I did bring each cylinder to TDC as I had the rack out for my cam install so it was easy.

However, when I swapped stock springs before the cam install I used the procedure on ls1tech and had no issues for 6000 miles. When I installed the cam I double checked them before removing and all were still at 22 ft/lbs.

 

You are using aluminum threads to compress your valve spring to possibly a full open position, and aftermarket valve springs to boot that could be as high as twice the stock seat value. I personally wouldn't do it, thats too much load on limited thread engagement. It also affects your bolt preload, which is based on the above procedure so all your bolts will have a different preloads.

 

I'm doing just oem direct replacement here, if that matters.

 

The procedure I posted above is taken directly from the OEM service manual.

 

I have not done an LS1 yet, but lots of other engines. Why chance a short cut.Even Cobra4B said he did his Yella terras to DTC.
When in doubt refer to the manual. You can never go wrong with the manual.
I feel safer standing behind my work with a manual than somebodies opinion especially on flat rate.
The extra steps of finding top DTC is not that big of a deal.
Somebody once told me believe about 5% of what you read on the internet.
Good luck with what YOU decide