01-02-2013, 01:20 PM
#262
(01-02-2013, 01:01 PM)Simpler=Better I think that 0.136" was the biggest OM616 has gone so far. Can you try a homemade sandblast/extrude hone to radius the inner edge of the holes?
It should be noted that am currently running .136" dia holes on my 616 PCs which have a smaller burn tube ID than the 617a PC.
When I go to install the new injectors, I am going to increase the holes to probably .145"
My goal is to have more hole area than the burn tube has so the pressure head is at the base of the burn tube, which should increase the filling velocity and chamber swirl.
The 617 pc has a larger burn tube ID, so it would require larger holes to match the area % differential I am currently running in my 616.
It is possible to add a hole between the two on the back side, this would allow for overall smaller holes while increasing total area, tapering the inlets sounds like a nice thing too.
If you add an additional hole, do not use a regular drill bit, I would recommend using a M.A. FORD, Hi-Rock drill, it is made for hardened steel and is very rigid, makes a nice clean hole. Or any other straight flute drill for hardened steel for that matter would be better than a helical flute drill.