ronlaughlin
It seems to me that the 5/32" hole is a bit smallish for the tap.
It is.. what I wanted to suggest is that he 5/32nds is what I think might be the optimal minimum size..
I was wondering if it would be best for me to use a #21 drill, instead of the 5/32" drill,
#21 is the bit to use if you are doing it at home...
i would end up with a slightly larger than 5/32" fire channel, and am wondering if that would be a bad thing.
It is not a bad thing - but there is a size that may be to large and compromise the strength of your BP... I have never seen a reall Accura plug so I do not knowwhat that size might be.
I will post these instructions as written by (
Lemoyne) Lee. These were written using a dril press to accomplish the work. I am/was using a machine shop lathe to accomplish the work. I have now also decided to complete them on a drill press - I have done enough on the lathe to feel confident in doing on a drill press now.
if you do this project do not turn the drill any faster than 180 RPM and let it feed at its own speed and use a good drill, carbide if you have it.
I mounted the BP in the milling table vise on my drill press and using a #1 drill I line the hole in the BP up with the drill so it was on dead center.
I then took out the #1 drill and mounted a #8 drill and drilled out the touch hole, then I took that out and stepped up to a # 16 drill then stepped up to a # 21 drill. I ran the drill all the way through the seat for the 209, this has proved to have a major effect on reducing the carbon build up under the 209 seat. This is the right size for tapping a 10-32 thread.
then I took a 25/64 drill and inset the end of the BP the distance of 4 threads.
I then mounted the tap in the drill press and took the top belt of the press off; lowered the tap to the breach plug and put about ten pounds of pressure on the handle of the spindle on the drill press turned the top pulley of the drill press by hand until I had 9 complete threads since the Lehigh V liner has 7 and a half threads this is just right.
Hope this helps....