FLYNAVY30

iTrader: (1)

....but whats the easiest way to find TDC of the compression stroke on the #1 cylinder with the timing cover installed? Im doing a head swap so the timing cover never came off and I need to find TDC so that I can torque the rocker arms in accordance with the service manual.

Thanks.

joecar

TDC at the top of compression will have both valves closed.

FLYNAVY30

iTrader: (1)

understood, but I need to position the motor manually prior to bolting on the valve train in order to properly torque the rocker arms, so at this point, none of the valves are open, regardless of piston position as the rocker arms and push rods havent been installed yet

joecar

When you install pushrods/rockers and loosely snug them down you will see which valves are being opened.

You can tell TDC by having the spark plug removed and seeing if the piston is up.

FLYNAVY30

iTrader: (1)

ok, now Im following

703 CAMAROSS

You can also pull the spark plug, place a paper towel in the hole and when it blows out it will be on the compression stroke, that's a good method when working by your self, if you have a friend, they can just put their finger over it and wait for it to blow back.

ThumpnZ28

iTrader: (23)

Good advice ^^^

71ANTICARB

iTrader: (23)

Why would it matter if the engine was at tdc? The rocker are not adjustable like on the old motors.

bww3588

iTrader: (49)

To get a proper torque value. If your torquing the rocker bolt, while working against the valve spring, you will hit 22 ftlbs quicker, and when the valve actually closes, the torque value on the rocker bolt will be less than 22 ftlbs.

71ANTICARB

iTrader: (23)

Sorry but I don't see that since your torquing the rocker trunnion against the pedestal. Not against the paid and valve.

bww3588

iTrader: (49)

If the cam is not on the basecircle, you will be torquing against the spring and lifter. For every turn of that bolt, you will be opening the valve, compressing the spring and lifter plunger.

FLYNAVY30

iTrader: (1)

additionally, its the procedure in the GM service manual....some engineer way smarter then I got paid to write a procedure for a reason....good enough for me

TypeSL2

iTrader: (2)

+1

James