CLAYMACs2000

I am getting ready to replace my valve springs in 2000 LS 1. I'm going to leave the heads on the engine and would prefer to leave the spark plugs in. I just replace them when installing my headers and would rather not fish them all out again. Are there any tricks to holding the valve shut and not falling down into the cylinder without using the air compressor adapter in the spark plug hole?

Zmg00camaross

iTrader: (11)

I used the TDC method. But had the plugs out and verified it was at TDC. This isn't something to try and save time on. Do it right.

sick_0n3

iTrader: (7)

I prefer TDC, easier and less of a chance of anything going wrong.

CLAYMACs2000

when using the TDC method, what degree do you put the crankshaft for each cylinder to be at top dead center?

sick_0n3

iTrader: (7)

The balancer has no mark unless it was previously marked in which case I wouldn't trust. I know you said you don't want to pull plugs but just pull your number 1 plug then follow this sequence for changing the springs

1. Place a straw pencil or something into the number one cylinder. Manually turn crank till the item stops rising (make sure to ease it out so it don't get pinched). When this happens, pistons 1 and 6 are at top dead center. Change springs on these cylinders.

2. Rotate crank 90 degrees clockwise. Now pistons 8 and 5 are at TDC. Change these springs.

3. Rotate 90 degrees clockwise again. 7 and 4 are at TDC. Change these springs.

4. Finally, rotate crank another 90 degrees. Pistons 3 and 2 are at TDC. Change springs.

Pull the rockers first and it'll be easier to turn the engine by hand.

CLAYMACs2000

Sick_On3, that's good information. Thanks for the input.

My engine tech at work told me that he trusts the valve seals to hold the valve up when changing springs. ???

sick_0n3

iTrader: (7)

No problem.

I honestly would not trust it, all it would take is one bad seal or to bump the vavle and your hoping it didn't fall all the way in. Plus if your pulling the springs why not change the seals to? A lot of work to have to redo if a seal goes bad just to save $20-$30 now.

RONSBLACK1998TA

I wouldn't trust the guides to hold up the valve either. I pulled all the plugs and used the TDC method that sick_0n3 said when i changed my springs. Also it's really a good idea to change out the guides since ur already there anyway. It's just good insurance.

redbird555

iTrader: (14)

The guides are actually pressed into the heads to keep the valve from wearing into the casting. I assume you all are talking about the seals in which case, no they def wont hold up the valve. Use the TDC method, and they should always be replaced especially when they only cost 25 bucks and they are intake/exhaust specific

Blowerman

You can also use a clean cotton rope and load about 6 to 8 inches into the spark plug hole, then run the piston up against it.
It will hold the valves tight against the seat.
Don't load a bunch of rope in there because it could tangle and not come out.

CLAYMACs2000

Well, I used the TDC method and left the plugs in. Only two valves dropped while I was compressing the new spring. I found that a cheap pen magnet was the perfect size to slide through the valve seals and retrieve the valve.

mjs1012

iTrader: (36)

I also did the TDC method when I did my cam swap. It wasn't to hard to get the pistons at TDC, but make sure to take your time and do it right.

oldmano2z

ya know this thread is typical of ls1tech. you guys pool your knowledge and help each other out. FANTASTIC BOMBASTIC !!!! I just wish this type of interaction was around during the 70's and 80's . but it's here now and I built my 02' from this site. I will continue to upgrade my ride from here. American muscle!!!!!! hoorah! the oldman......