Quote:
Originally Posted by afterburn 549
I am not sure how a spark plug would take away from compression or C/R.
With Hemi style chambers the big problem is getting the flame front over the top of the piston crown.
With twin plugs this problem is circumvented and as a plus the timing can be back offed with out performance problems
|
The second plug drilling looks to me to add about 1 cc to the combustion chamber volume. See below photo of a plug recess.
One extra cc in the last engine I built would have lowered the CR from 10.2:1 down to 10:1
