Can anyone tell me the thread of my 68 Lightning rocker cover please
John
1/4 CE126 BSF according to spares book.
oh dear, here we go again...1/4BSF are not the same as 1/4BSC, both 26tpi but different thread forms. 55 against 60 degrees.
Yep! 1/4" BSF thread goes in the head and cycle thread for the nuts. I've always wondered why they do this. Anyone know why the different thread profile? (They are both 26TPI)
from an engineering point of view, we used BSF as easier to get fastners than BSC. ( I cleared the stores of fastners and BSC tooling)
as for profile, the 55degrees gives slightly more material than the 60.
threads in ally castings use a coarser thread to avoid the stripping of threads when tightening, in steel such as nuts, there is more strength in the material so not as much of a problem
:) :)
As you only need to tighten them enuf to make the top oil tight I use !/4 allen screws. Not correct??? you're right. But as a lot of us are using pattern parts, it's not a problem to me.
Mike 8) 8) 8)