Actually there is a m24x1.5 plug that is a tapered thread. Use it with a straight tap and you get a foolproof setup. Issue with using NPT is the coarseness of the threads can allow for very little thread engagement. Which gives a poor fit. Technically you need 5 threads of engagement for a vapor tight seal.
Actually there is a m24x1.5 plug that is a tapered thread. Use it with a straight tap and you get a foolproof setup. Issue with using NPT is the coarseness of the threads can allow for very little thread engagement. Which gives a poor fit. Technically you need 5 threads of engagement for a vapor tight seal.
Some of the Sisu engines have a female straight thread with a male tapered fitting in them. Many of them leak. We change them to a straight thread with a copper washer.
I did the same search a year ago and no such luck in the US. I ended up buying 150pc min order from a vendor of ours in Europe. It took over 3 weeks to get them and shipping just added to the cost. I had a bunch of heads to do and future ones so it was worth in IMO. I can supply you with 11 of them if you still need them just shoot me a PM. For others to know I soaked them in red locktite and mine are leak free for over a year now. I ran my 24X1.5 tap in with some tap magic and no drilling just tap as normal. Like Dan said I like the fact you do get more TPI. I did have fear using the straight thread with the metric plugs. Now I will do them to all my builds from here on out. I have also done this using the 3/4" brass npt plugs in the past. I used a locktite PST567 sealant on those and they are working great also. Its just the drilling for the 3/4" that adds cost and time.
Actually there is a m24x1.5 plug that is a tapered thread. Use it with a straight tap and you get a foolproof setup. Issue with using NPT is the coarseness of the threads can allow for very little thread engagement. Which gives a poor fit. Technically you need 5 threads of engagement for a vapor tight seal.