m103~300e 1991 expert help needed
 

Hello.

Have just replaced my head gasket on the above engine.

However, I now have the valves hitting the pistons, no damage!

Have followed the instructions for mecanical timing, that is TDC on the harmonic balancer, and the dot on the cam shaft in line with the marker, and both valves on#1 closed. The cam sprocket in the pin hole for that purpose.

Question for the experts, it appears that when the piston on #1 is on top dead center [ noted visually] the harmonic balancer shows it in line with the magnet for the ignition timing? Suggesting that is TDC and not O/T?

Question, what should you use as the TDC mark on the harmonic balancer?
Tha manual say's use O/T, reference Engine job 05-2230 mech., timing

Thanks

Brian

When the balancer is at the O/T mark the #1 piston also has to be at the top.

The magnet ONLY serves as a reference for dynamic timing with a scope.

The timing mark on the camshaft must align with the mark on the cam bearing when the piston is a TDC.

I hope you haven't bent any of the valves.

Tom W

m103~300e 1991 expert help needed mech timing
 

Guys,

Thanks for your response.

Didn't damage the valves turning by hand.

Here's the weird part, with the head off and observing the piston on #1 and the timing balancer position at O/T mark it does not put the piston at TDC, rather a bit lower.

However if we move it to where the magnet is located, the piston is now exactly flush with the top of the block?

There's something I'm are not getting, the manual is very clear on the positioning for mechanical timing?

At the O/T position it taps the pistons? At the magnet position its clear of the pistons.

Whats going on.

Brian