Porting the 99/00 BP head
#68
Porting update. Finally got the valves out and did some work on the bowls today.
It has been talked about a lot in this thread and in the Keegan articles but, the step where the valve seat machining meats the casting texture was really bad. Not visible in the pictures but this step is even worse on the short-side or inner radius.
I dont have the paper flap wheels, so this(Below) finish is probably how i'll leave it. Intake side is an 80 grit paper roll.
Exhaust side and chambers will go 120 paper roll and then quickly by hand with 240 emery cloth. Maybe.
It has been talked about a lot in this thread and in the Keegan articles but, the step where the valve seat machining meats the casting texture was really bad. Not visible in the pictures but this step is even worse on the short-side or inner radius.
I dont have the paper flap wheels, so this(Below) finish is probably how i'll leave it. Intake side is an 80 grit paper roll.
Exhaust side and chambers will go 120 paper roll and then quickly by hand with 240 emery cloth. Maybe.
#69
Done. Time to drop it off for machining and valve job.
I would say I have 15 hours in this head, spread over 4 days. I used 4 of the larger 1/2" diameter 60 grit rolls, 8 80 grit, 2 120 grit, 2 smaller 1/4" diameter 80grit and 2 small 120. I also found a place and use for all the carbide bits, glad I bought the 4 piece set and not just a tree shaped one.
Don't do this by cylinder like I started to. Because I used a spare head, I began by doing 1 intake and 1 exhaust runner not knowing how it would turn out.
Much more consistent(better) results will be earned by doing it in complete stages:
-All intake runners with carbide.
-All exhaust runners with carbide.
-Combustion chamber carbide work; de-shroud, short side radius, bowl work, whatever.
-All intake runners and bowls 60 or 80, ideally finish with flap wheel which I didn't have.
-All exhaust runners and bowls 80, then 120, then polish. (I jumped from 120 paper roll to 240 emery cloth. Something else in between would be ideal)
Definitely DIY-able.
I would say I have 15 hours in this head, spread over 4 days. I used 4 of the larger 1/2" diameter 60 grit rolls, 8 80 grit, 2 120 grit, 2 smaller 1/4" diameter 80grit and 2 small 120. I also found a place and use for all the carbide bits, glad I bought the 4 piece set and not just a tree shaped one.
Don't do this by cylinder like I started to. Because I used a spare head, I began by doing 1 intake and 1 exhaust runner not knowing how it would turn out.
Much more consistent(better) results will be earned by doing it in complete stages:
-All intake runners with carbide.
-All exhaust runners with carbide.
-Combustion chamber carbide work; de-shroud, short side radius, bowl work, whatever.
-All intake runners and bowls 60 or 80, ideally finish with flap wheel which I didn't have.
-All exhaust runners and bowls 80, then 120, then polish. (I jumped from 120 paper roll to 240 emery cloth. Something else in between would be ideal)
Definitely DIY-able.
Last edited by doward; 12-26-2013 at 04:56 PM.
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