#1 TDC

[akadeutsch]

If my timing marks on the crank and cam pulley are aligned does that mean that I am at #1 TDC of the compression stroke?

[jsawduste]

No

[akadeutsch]

Then my question becomes. How do I find #1 TDC on compression with the head on. Do I have to take the head back off? I am trying to sync my Cam position Sensor.

[the grey ghost]

Mount you harmonic balancer, then stick your little finger in the sparkplug hole, watch the rockers move, they open and shut twice whey rotation,

[Cheromaniac]

If my timing marks on the crank and cam pulley are aligned does that mean that I am at #1 TDC of the compression stroke?

How do I find #1 TDC on compression with the head on?

Not necessarily. The no.1 piston could also be at TDC at the end of the exhaust stroke during the overlap period when both valves are slightly open with the valve springs slightly compressed. If the same piston was at TDC at the end of the compression stroke, both valves would be fully closed with the valve springs at their installed height and some lash between the valve stems and the rocker tips.

[SilverXJ]

Two ways;

1) With the valve cover off watch the intake valve. Watch it open, then close. Once it closes rotate the harmonic balancer to the TDC mark.

2) Remove spark plug #1. Place finger in/on the spark plug hole. Rotate engine. When you being to feel pressure/ hear air pushing past, rotate balancer to the TDC mark.

[the grey ghost]

That's what meant to say, I should stop trying to explain and just copy and paste what silver posts