Navarro 8ba Heads

[KiWinUS]

Originally Posted by 69a

The Navarro heads that I have, in an engine supplied by H&H have the spark plug area too thick in the casting, about 4 threads to thick. The entire plug including the electrode is up inside the thread. The plugs get fouled every 500 to 1,000 miles. You can't put a longer plug in because the valve is too close. If he hasn't corrected this with the casting you will need to get some material removed.

Question. So if H&H built this engine what did Mike say about fouling plugs so often?