intial timing?

[metcoll]

my engine (six pack pistons, lunati 240/250 520/547 cam) likes a lot of intial timing 25degress...what would cause this...

[firefighter3931]

The increased duration and tighter lobe seperation will create a larger overlap and reduce idle vacuum. Increasing the base timing improves the idle quality & throttle response.


Ron

[metcoll]

would this mean my engine would have low compression...engine builder  told   me  with those pistons i should be right @ 9.5 compression....thx

[firefighter3931]

That compression sounds about right with an open chamber head and composite head gasket 

That's a healthy cam so it needs lots of spark lead at idle....nothing abnormal 


Ron