|
|
Posted by ChrisCase [63.199.241.115] on Saturday, April 23, 2011 at 18:42:12 :
In Reply to: Let's try this link... posted by Eric B. [99.100.189.119] on Saturday, April 23, 2011 at 11:38:36 :
That re-shaped combustion chamber that fits tighter around the exhaust valve helps it breath better. On exhaust, the closer fit helps the gasses flow out the open valve.
It is that area that I ground to a rounded edge on my head. It was sharp enough to cut. Round edges will keep it from getting so hot that it ignites the next charge. I hope.
I also like to center punch a row of dimples along the siamese divder. Punching raises a ring around the dimple, which grabs the gasket, keeps it from blowing back and forth between the two combustion chambers. Time will tell, I haven't driven one with the center punching more than 10,000 miles before selling it.
Anyway, since the same gasket has to fit older heads too, it has to have a bigger hole than needed for the newer head design.