ok so we were changing the valve seals on a buddys car and i guess the circuit blew for the box for the power so the compressor shut off and the intake valve dropped. can we just take off that one head and it'll be ok? or do i gotta take off bith heads now? thanks. also its a 99 ls1

 

I would try a small magnet down the valve guide and see if you can get it sucked back up

 

ive tried that and no luck at all. it reaches it but cant pull it up and ive tried a few diff. magnet

 

one other trick I have seen is necking down the shop vac to where it is a good fit around the top of the guide and suck it back up.

If all that fails just pull the one head. The other can stay on.

 

Try and turn the engine over by hand to see if you can get that one piston to come up and push the valve up. We dropped a valve once and this method worked good.

 

we tried the shop vac aswell with no luck but havent tried turning the crank yet. well give that a try thanks guys

 

next time instead of using the compressor just use the TDC method. That is what i did and didnt drop one valve.

 

I used both TDC and the compressor method for that exact reason :-). My compressor was too small and ran continuously to pump air into the cylinder and blew the circuit and luckily we grabbed ahold of it before it fell to far.

 

Key word there is turn the motor over by HAND. Good luck keep us posted on the outcome.

 

how did the cylinder lose air that fast? i just did valvesprings on my dad's lt1 a couple months ago using this method - after the compressor shut off it would hold the valve up for at least 10 minutes? it's a stock longblock motor.

 

I had that happen too, when it gets low on air the slightest touch of the valve will drop it. Rotated the engine by hand and it cam back up.

 

thanks guys we just took off the heads and now decideing which route to go