Phasing crank to cam trigger

Hi - I'm just setting up a crank trigger wheel ( 60-2 ) with V/R pickup and for my cam trigger will use my distributors reluctor with 1 tooth left on it as a sync signal - Its a V/R pickup as well . How is best to phase them ? Both triggering at the same time or stagger the gap/tooth so many degrees apart ? If staggered which trigger should signal first for best starting and performance . Thank - Ken.

Phasing on this sort of trigger system is pretty straight forward. You need to make sure that the cam input occurs basically anywhere except the missing teeth. This gives you a very wide window for accurate detection without any potential for confusion. Depending how you're setting up and adjusting this, you do need to be careful as the phasing of the rotor arm to the output posts in the distributor cap is critical and needs to be correctly aligned to avoid cross firing.

Hi- Thanks for your reply . One more question . Im doing this semi sequential conversion on a motor all ready running with group fire injection and a distributor . So i just need to sort out the timing for each trigger . What i intend to do is without disturbing the position of the distributor ( which is set already at 10 degrees BTDC ) i will remove the 8 point reluctor , grind off 7 teeth and leave the one sync tooth .Then reinstall the reluctor. So this will still be timed at 10 degrees BTDC . So far is this ok ? Then i have the trigger wheel installed with the gap at approx 90 degrees BTDC ( Its just convenient there ) . How is this position input in the ecu .? I just want to set things up so as to have the best chance at a quick fire up . Also when i get a timing light on it to set the timing point in the ecu which pickup is the ecu now referencing ? trigger 1 or 2 . ? . Any other tips you can give to help will be great . Thanks - Ken

What you're suggesting sounds reasonable to me. The specific offset value will depend on what ECU you're using as there isn't a single method that all ECUs use to define the offset. This doesn't really matter though as you will still need to accurately confirm the timing with a timing light so prior to startup you can simply disable the injection and coarsely adjust the timing until it's approximately correct. You can then enable injection and allow the engine to start.

Just as an example with the Link ECU, the offset value in your case would be approximately 270 degrees as it is essentially how many degrees the EUC needs to advance from the missing teeth.

As far as the ECU is concerned, the timing calculations are based off the 60-2 crank wheel (trigger 1). The sync or trigger 2 input is used to tell the ECU which cycle it is on. During initial startup the ECU waits until it sees the sync input before it achieves synchronisation and can actually begin supplying fuel/spark.