I found some 1/4" pencil zincs that seem to be the same as the Camp E-OBC. I screwed both the original brass zinc from the engine and the new ones into a 1/4" female pipe piece I had, and both seemed to screw in without a problem. Anyone see a problem using these in my engine?
Thanks ! I just was concerned about the difference between NPT and BSPT threads. I thought maybe the two threads were alike enough that if I tried to use one where the other was called, for, I could screw up the threads in the heat exchanger.
There is a difference in the threads.
NPT is a taper thread.
BSP is a parallel thread.
There is also a slight difference in thread pitch.
I had assumed from your initial post that these were BSP but if you are careful, you should still be OK.
I had always thought that the British had two thread patterns; BSPT and BSPP, which are British Standard Pipe Taper and British Standard Pipe Parallel. The British use different thread pitch and angle than NPT and NPS (US National Pipe Taper and US National Pipe Straight).