Re: Timing chain tensioner pivot bolt
Posted: Mon Jan 01, 2018 10:18 am
Well some interesting findings people. Rohan I think you might be on the right track
with threads. I have attached a close up photo of the tensioner pin and the thread form gauge held
up to it...note that it is the 18TPI gauge but it does not fit perfectly...almost right but not quite.
I then grabbed a main oil gallery plug which is the same size and looks to have the same thread,
but found that it isn't...it screws in about 1.5 turns into the head, then binds...I tried the 18TPI thread gauge on the gallery plug thread and it fits perfectly, so pipe thread the pin must be.
I could not fit or count the internal thread in the head.
The thread number of 19 was mentioned, the only 19 TPI thread is on the G series BSPF where G1/4 and G 3/8
have 19 TPI (parallel series)...i am not that familiar with these thread forms. That info was taken from the Sutton Tools guide Tapping drill sizes.
So I am still non the wiser for this. Why the odd ball thread size? it does not make sense?
All that I know is that the new pin that I have here screws in perfectly into the head...but if one was making a repair, I would need to grab a pipe thread form gauge which I don't have...and check...could be that it's 19TPI. Maybe contact Burtons or others to see what light they can shed on what the thread form is.
Sorry i cant be more helpfull.
Col.
with threads. I have attached a close up photo of the tensioner pin and the thread form gauge held
up to it...note that it is the 18TPI gauge but it does not fit perfectly...almost right but not quite.
I then grabbed a main oil gallery plug which is the same size and looks to have the same thread,
but found that it isn't...it screws in about 1.5 turns into the head, then binds...I tried the 18TPI thread gauge on the gallery plug thread and it fits perfectly, so pipe thread the pin must be.
I could not fit or count the internal thread in the head.
The thread number of 19 was mentioned, the only 19 TPI thread is on the G series BSPF where G1/4 and G 3/8
have 19 TPI (parallel series)...i am not that familiar with these thread forms. That info was taken from the Sutton Tools guide Tapping drill sizes.
So I am still non the wiser for this. Why the odd ball thread size? it does not make sense?
All that I know is that the new pin that I have here screws in perfectly into the head...but if one was making a repair, I would need to grab a pipe thread form gauge which I don't have...and check...could be that it's 19TPI. Maybe contact Burtons or others to see what light they can shed on what the thread form is.
Sorry i cant be more helpfull.
Col.