OST-036: Frankie - The Flogger from beyond the Grave

[oldeskewltoy]

OST's valves thread Wrote:Ported head w/ stock valves WITH back cut
..........Lift - Exhaust
.050" - 27.53
.100" - 59.83
.150" - 92.16
.200" - 115.31
.250" - 124.52
.300" - 128.77
.350" - 131.11

So in the photo below, the top view is a typical OST ported head, but Frankie has a bit more.....




Frankies exhaust ports have been changed. There are a few changes, 1) the roof of the exhaust port now carries a gradual taper, in a stock port, and even my typical ported ports, the port roof is flat, 2) The inside of the port has been changed (following Blacktop example) and there is no longer a roof splitter with a gradual end, the end is now abrupt and well inside the port. 3) Finally, the port walls have been opened up a bit more to bypass the guide and valve stem.


And the results.........
.050" - 27.73
.100" - 60.14
.150" - 93.34
.200" - 119.77
.250" - 131.71
.300" - 136.94
.350" - 141.04
So Frankie's exhaust ports can now flow an added 10 cfm...... @ 9mm of lift