Chuck Norris

hello all i have a question regarding the installation of a gear drive on a GMPP 290hp 350. i removed the stock timing set and made what i thiknk is a big time error, i moved the crank about a quarter turn to the left. now what i need to know is how do i find TDC without removing the head?

oh and yes this is my first post, and the engine will be going into a 89 t-top RS

jv9999

iTrader: (1)

Can't you just stick the cam and crank sprockets back on long enough to line it back up?

fastregalwe2

move it 1/4 turn back to the right with the timing set back on it.

ksith

the way i've done it is remove the number one plug and stick your finger in the hole there. also remove your dist cap. look at a manual and find out where your dist should be pointing to for the number 1 position. have a friend rotate the crank with your finger in your hole. you should feel it either sucking on your finger or trying to push it out. what you want is for the dist to be in the area where the manual says with your finger being pushed out. once you feel it start sucking STOP. obviously you have to go really slow. fire it up if it doesnt start you have it off 180 degrees so all you need to do is remove the plug note where the dist was then do it all again till the dist is 180 degrees opposite. sounds complicated when im typing it down buts really easy works for me all the time

SpitotRs305

that would work if he was talking about dist timing NOT cam timing....and incorrect cam timing can lead to severe engine damage.... is the engine in the car or out?

igotta355z28

iTrader: (1)

dont make it any more complicated then it is people, its simple take out the number one cylinder spark plug, put the balancer back on and make sure you have a timing tab (disclaimer this will only work as long as u know that yout balancer outer ring has not sliped any...i.e. new balancer) put your finger over the spark plug hole and turn the motor over, (would be nice to have a helper finger) turn the motor over untill u feel the air rushing out of the spark plug hole (that means the piston is coming up on the compression stroke) now just line up the timing mark on your balancer with the 0 mark on your timing tab, your motor will now be at top dead center on the 1 cylinder.....

AlkyIROC

Even with a gear drive (you probably pull it back off soon anyway) you still need to line up the timing marks on the gears. Gear drives are annoying. I had a set on my race engine for one day before yanking it off and putting a good chain back in.

Rotate the crank back to roughly where it was. Line up the marks on the crank and cam gear. That's assuming you already had the marks lined up when you took the chain off. If not, then you'll need to turn the crank and camshaft until the marks line up. It'll be hard to turn the camshaft with the lifters still on the valves.