Hi All,
Attempting to change the timing belt myself on the EJ204 motor for the first time.
It has quad cams, and my question is about adjusting the cams so that all the markers line up (highlighted yellow in image below) when the belt is off.
I understand you should line up the markers with the old belt on; but it can't be helped that once the belt is off, the cams can spin independently and often need to be rotated so that the markers line up again.
I've heard that the passenger side intake cam (circled green in the image) apparently has AVCS and can easily flip violently when rotated, and the valves can collide with eachother or with the piston head if they happen to be in the way - this is what I want to avoid! The other cams apparently do not flip violently when rotated.
I've heard that the safest way to tackle this is to line up the markers with the belt on, and use a cam lock tool from Company23 to lock the AVCS cam to the one directly below before taking off the belt. I spoke with Company23 but unfortunately their cam lock tools only fit turbo models and mine is naturally aspirated.
So, it seems I need to make do without the tool, and I want to understand what measures I can take to prevent the valves, piston head from colliding and how to do the job safely.
So the questions I have:
1) I've trawled forums and comments, and read that (for boxer engines) the piston head is mid way in the cylinder when the marker on the crankshaft sprocket is lined up (not at TDC as would be the case for an inline engine) meaning that the valves are not at risk of colliding with the piston should the AVCS cam flip - is this true?
2) To avoid valves colliding with eachother, I found in the 2004 DOHC Turbo service workbook that there is a particular direction that the passenger side cams (they call it LH cams in the manual. image below) need to be rotated to avoid valves colliding...
Do you know if this also applies to my engine? It seems to suggest that both the intake and exhaust passenger side cams can flip violently? Why does this rotation direction apply to the passenger side cams and not the driver side cams too?
I am happy to hear every ones experience with this.
Thanks