HELP! Timing concerns

[anotherdom]

Right all, finished the upgraded valve springs. Followers and cams replaced, and timing chains back on. I've advanced the exhausts one tooth. But, I'm not convinced the rear bank is timed correctly. I only marked the positions of the chain on the camshaft sprockets, thinking the crank wouldn't move and I could just replace the chain. Wrong assumption - the valve compressor uses a compressed air line to hold the valves closed. Turns out the pressure was easily sufficient to turn the engine! I went overboard with the front bank, marking all positions, leaving in gear with the handrake on and watching the crank each time I connected or disconnected the airline. So, I now need advice on how to confirm my timing. The chains have white painted dots, which I assume are Ford markings representing the standard timing, though they could have been added by NMS at build I suppose? There are also lines on the rear of the camshaft sprockets, which I would have expected to align at No1 TDC - they dont! Similarly, should the markings on the front bank align at No4 TDC? Finally, can anyone confirm No4 compression TDC should be 120 degrees after No1.

Thanks for any and all help! Dom.

Edited by anotherdom on Tuesday 6th March 18:42

[GTO600]

Not sure if this helps

http://nobleforums.com/showthread.php?t=4028&h...

[anotherdom]

Bang on Kevin, looks like my understanding was correct and my chain has slipped. Timing cover will have to come off again!

Dom.

[anotherdom]

Peterguk has also been really helpful, and pointed me towards the Ford engine repair manuals linked from the US site. I can absolutely confirm that the cam timing on my 3R was not to Ford standard, but will be now. It appears the oft disputed cam timing 'mod' is not a myth!