Technical How do you time the 16v after the timing belt slips?

[FlowerFiatx]

How do you do this? How do you know the pistons are at the right stroke

 

[judderbar]

How do you do this? How do you know the pistons are at the right stroke

https://www.fiatforum.com/punto-ii/453856-16v-1-2-engine-cam-belt-change-how.html?p=4292823



To get the stroke correct, when you rotate the engine in the normally operating rotation, get all 4 pistons level when number 1 piston is going down in the cylinder.

 

[FlowerFiatx]

https://www.fiatforum.com/punto-ii/453856-16v-1-2-engine-cam-belt-change-how.html?p=4292823



To get the stroke correct, when you rotate the engine in the normally operating rotation, get all 4 pistons level when number 1 piston is going down in the cylinder.

Perfect, that's what i needed.

But how would you do this job where timing is already out. If i remove the belt and insert the timing tools, there is still a danger when cranking that i will hit valves.

If i remove the head and eyeball it, timing may be off when reattach head.

If all pistons are level and piston 1/4 were going down when level will this ensure the bottom end is timed?

Also silly question but which way do i crank the engine

 

[judderbar]

Perfect, that's what i needed.

But how would you do this job where timing is already out. If i remove the belt and insert the timing tools, there is still a danger when cranking that i will hit valves.

If i remove the head and eyeball it, timing may be off when reattach head.

If all pistons are level and piston 1/4 were going down when level will this ensure the bottom end is timed?

Also silly question but which way do i crank the engine

I see what you are saying. I think the answer is the timing has to be a very long way out before you hit the valves if the belt is still attached.

However if the head is off then you can position the block exactly for correct valve timing with all 4 level with number 1 going down when the engine is rotated clockwise looking from the crank pulley. I found it hard to get my head around this idea myself. It is difficult to think about it because the block has two identical movements of metal involving different mixtures of gases. two up strokes and 2 down strokes for 4 strokes. The meaning of the down stroke in the working engine only gets fixed once there are valves in place.