I bought a 24/2 back in 2005 and a 15KW head for a generator. I have been working on it ever since in my spare time. I started it up last weekend and I noticed some coolant dripping around the base of the manifold where it touches the engine as well as the hose barb king fittings that screw into the manifold. The threads were real loose and I thought the threads maybe BPT instead of NPT. According to the documentation I could find on it, the 1.25" pipe has the same TPI and should tighten up just like the BPT was NPT even though there is a 5 degree difference in thread angle.
The fitting was real loose in the threads and would not tighten and bottomed out. I put a lot of Teflon tape on it but it still leaks. I would think that if the pipe thread die was wore out, the threads would be shallower and irregular and the NPT pipe would not thread on. The threads look clean and sharp in the manifold. My first suggestion was to JB weld the hose barbs onto the manifold. I will probably try that since my other thought was to drill out the threads and try a 1.5" thread. I don't know if I have enough material around the perimeter of the manifold.
I have questions.
1) Is there some other thread standard other than NPT and BPT?
2) Do they make hose barbs for this oddball thread?
3) If I buy new manifolds, will they have the same problem?
4) Does anybody sell coolant manifolds with good NPT threads?
Thank You for any help you can provide. I promise to have some pictures ready for my next post.
Dave