tapered pipe fittings - what threads?

[mightyohm]

I have a sneaking suspicion that the tapered threads used on the engine are BSPT, and not NPT. Is that right?

Examples are the fitting for the drain pipe on the side of the block and the water pump fittings. This wasn't obvious to me until today, but the TPI is one thread different between the two standards so it's important to know which is which.

 

[mightyohm]

I answered my own question and wrote up the answer here:

http://wavelen.com/2018/03/15/painful-lesson-of-the-day-npt-vs-bspt/