skabrock5 wrote:nice, big difference there. incredible how much flashing material is left from factory.
whoops... sorry I missed this...
yes... and no... remember this is 30 years ago... and it is mass production for profit....
from another forum wrote:Wouldn't these "bad" heads have better
pressure recovery zones?
not disputed.... BUT.. the time required/amount of work involved makes it significantly less desirable. Also to consider is the irregularity of the "flaw"s occurance.
chamber #1 has no "flaw"... chamber #4 has only a minor "flaw". Do I weld up chambers 1 and 4 and shape them to equal the finished chambers of 2 and 3? My typical finished head goes out the door for under $1500, some under $1000
so... to again answer your question... Yes... these heads would have better pressure recovery, but the work involved makes it less affordable/attractive.
"Pressure Recovery" - is a concept researched by Darren Morgan (Induction Research and Development expert). In essence.....
'pressure recovery' refers to efficient slowing of fluid velocity and transforming the kinetic energy into pressure. In the runner, and especially through a partially-open valve, the velocity is high and the pressure low. In the cylinder, the opposite is true. A gradual transition, as in the exit contour of a carb venturi or through a tapered-hole carb spacer, accomplishes this. Blasting a high-speed air jet into a a big, still cylinder does not.
to simplify this even more(to better visualize)... think of the valve opening inside a funnel.....
