Finding #1 tdc to "set" the valves?
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Finding #1 tdc to "set" the valves?
Ok so on the GM procedure it looks like they say you are on #1 tdc on compression stroke when your camshaft dot is at the 12-oclock position and the crankshaft dot is at the 12-oclock position so you can adjust both valves at that time. Or are you saposed to have the camshaft dot at 6-oclock and the crank dot at 12-oclock?
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Put a pushrod in the intake of cylinder #1 and keep a little finger pressure on it. Rotate the motor until the pushrod goes up and then down (valve closes). Then rotate until the dots align, which should be approximately 1/3 turn from closure. You have to keep a finger on the pushrod to ensure the lifter doesn't hang in the lifter tray.
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Put a pushrod in the intake of cylinder #1 and keep a little finger pressure on it. Rotate the motor until the pushrod goes up and then down (valve closes). Then rotate until the dots align, which should be approximately 1/3 turn from closure. You have to keep a finger on the pushrod to ensure the lifter doesn't hang in the lifter tray.
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Lol your camshaft at 6 and crank at 12 is the same as them being dot to dot lined up. Do you mean with them both cosest to eachother #6 is on tdc or are you mean when they are 12 and 12 (furthest apart) they are on #6 tdc?
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Wtf are you talking about lol? Tdc has nothing to do with the cam lol? It really does. When your on compression tdc for a cylinder both the lifters on that cylinder are on base lobe and can be adjusted. Your the one not getting it. Yes number 12 on the crank you are at tdc. DUH! The camshaft turns at half the speed of your crank. You can turn the crank over twice and the camshaft will be in a different postion each time. Just because your on tdc for a cylinder does not mean you can adjust the valves on that cylinder. Your cam also has to be in the right spot so you "set" the valves at the right spot. My question is does the camshaft dot need to be at 6 oclock or 12 oclock. Yes I know 12 oclock always on the crank dot. It takes 720 degrees to complete you four strokes. Im needing to know when #1 will be on the compression stroke at tdc! No need to answer anymore though. This post is useless unless I get somone in here that knows what im saying. It will be easy to figure out where it needs to be when I tear it down and I can watch the valves move. WOW
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Both of the questions you asked are correct.
Now im more confused more than ever. Shouldn't be this hard.
I'll just find out when I get into the dam motor lol
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If you have #1 spark plug removed, then put your finger over the hole and rotate engine until you feel pressure (both valves closed). Then put a straw in the hole and keep going until it reaches its max height = tdc.
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Wtf are you talking about lol? Tdc has nothing to do with the cam lol? It really does. When your on compression tdc for a cylinder both the lifters on that cylinder are on base lobe and can be adjusted. Your the one not getting it. Yes number 12 on the crank you are at tdc. DUH! The camshaft turns at half the speed of your crank. You can turn the crank over twice and the camshaft will be in a different postion each time. Just because your on tdc for a cylinder does not mean you can adjust the valves on that cylinder. Your cam also has to be in the right spot so you "set" the valves at the right spot. My question is does the camshaft dot need to be at 6 oclock or 12 oclock. Yes I know 12 oclock always on the crank dot. It takes 720 degrees to complete you four strokes. Im needing to know when #1 will be on the compression stroke at tdc! No need to answer anymore though. This post is useless unless I get somone in here that knows what im saying. It will be easy to figure out where it needs to be when I tear it down and I can watch the valves move. WOW
#17
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Find TDC - doesn't matter if it's intake or exhaust stroke.
Push down on the pushrods - if they go down then torque the rocker, spin the engine 180* and tight the other half of the rockers.
Not rocket science - you just want the lifter on the cam base circle before torquing the rocker.
Push down on the pushrods - if they go down then torque the rocker, spin the engine 180* and tight the other half of the rockers.
Not rocket science - you just want the lifter on the cam base circle before torquing the rocker.
#19
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Find TDC - doesn't matter if it's intake or exhaust stroke.
Push down on the pushrods - if they go down then torque the rocker, spin the engine 180* and tight the other half of the rockers.
Not rocket science - you just want the lifter on the cam base circle before torquing the rocker.
Push down on the pushrods - if they go down then torque the rocker, spin the engine 180* and tight the other half of the rockers.
Not rocket science - you just want the lifter on the cam base circle before torquing the rocker.
#20
So you're saying that step 6 in the Service Manual page in Post #2 is wrong? It's saying that the dots on both the cam and crank sprockets should be at 12 o'clock when Cyl #1 is on compression stroke TDC.
Last edited by ZeeOSix; 09-24-2011 at 10:55 PM.