Originally Posted By: mechtech2
This is my point. With better combustion, you should retard the over advanced timing. it is much better to get your combustion right, and use less advance. Why stay married to ineffectual advance curves??
Timing is everything to a driver. It is the reason an engine feels responsive. It is better mileage. It is easier starting. And on and on and on...
No one enjoys driving any car with retarded timing. Many of us know the way a modern engine will smoothly pull a load, then oops, there goes your timing, now you get hesitation/sluggishness.
Blah. You wouldn't really want that if it was your car.
But if you don't need the extra advance, then it hurts.
Modify the timing to suit the better combustion you are now getting with better spark plug location!
It is similar to cars an motorcycles with two spark plugs. Much less advance is needed, and is a better solution overall.
Of course, depending on the stock timing(in correlation to TDC?), is there a feel for advancing the timing with these plugs ahead of stock timing, leaving the same, or retarding slightly?
I'm sorta torn between the points mech and Steve are making, let's put this into talk about the OP's app. If you could establish what factory timing is etc, would advancing or retarding the timing be best? Cons/pros of each? How about remaining at(reverting to) stock?
I was speaking very generally. Most people would choose the snappy throttle response and performance feel of an engine with the proper specified timing advance. Meaning maximum factory spec.
When the engine senses knock then it retards timing. Many PCM's do this in a cycle that you can feel in the power delivery, the engine will pull strongly then hesitate as timing is pulled in response to knock.
My only point was that I have seen much better (more) timing in some modern engines with a recessed plug location as it seems to diminish preignition thus allowing full factory advance earlier and longer.
If there is no knock - be happy.
if there is, uee the other plugs or use a higher octane fuel.
For street cars, it is unlikely that a 1mm longer plug would cause knocking or damage. Only gets the tip in a better firing position.
