Theres just too much of a rough step in the factory castings.
...And since I have such a nice valve job done on the seats, I took some time to do a little bowl work.
Easy does it here, you just want a smooth transition and removal of any lip. And dont crash the sanding drum into the valve seat!
In my opinion, this isn't porting. This is just good, quality engine assembly practice to free up the power that should be there. The original designs showed a smooth transition I'm sure, the real world effect of mass production casting and manufacturing gives less than nominal results.
Porting adds more power that wasn't in the design of the cylinder head, and it is an artform, mastered only by a very few and completely fucked up by most everyone else.
I have fucked up my share of heads to know better than to attempt any serious porting. Airflow is nonlinear and does really goofy shit contrary to your "logical" thought. And you always take way more off than you should.... Plus its messy enough just cleaning up these bowls, much less profiling the pocket, short side transition and any chamber blending.
Its a van, man.
But I will take it down the strip, I gotta at least once!
hehehehe... bowl job.... If wasnt a gud spellar I wooda typt blowjob....
|Detail shot of the bronze liners and necked guides for the viton seals|
|Before the bowl work|
|Number 2 in process|
|Number 5 done|