Topic: Cam Tower Stud install

[TheArchitect]

I have searched all over and found lots of info if there are issues with your cam studs, but little on just the re-installation.

I am just reinstalling them and wondering how much to thread them in before installing the cam tower and torquing them down.

Do you just just hide the all the threads into the head? or Bottom them out? Bottoming out seems risky since the holes are open to air or partially opening.

Thanks!

[754]

I think they thread in till they bottom.

[The Lone Builder]

I have just completed this task on a 750K2.

The stids do not bottom out; if you screw them in far enough, they will appear by the spark plugs - see pic. Then if you screw them in too far, you won't have enough thread to fit the nut on top.

Having found this out the hard way, I pulled them out, added some thread lock, as there is no way to torque them to a set value, and set the height at 44-45mm. This left enough thread to fit the cap nuts properly.

Sean

[PeWe]

Seal the threads with high temp thread sealer. Like this
https://www.permatex.com/products/thread-compounds/thread-sealants/permatex-high-temperature-thread-sealant/

I sealed the holes on the other side from the spark plug cavity with JB weld too after I had tightened the studs (max 10Nm) and head upside down. The head threads can be rather fragile. I have inserted time-sert thread inserts for all those cam studs in my CB750 K6 head. (lots of $$$ burried in that head).  If there is no thread inserts like time-sert or helicoil type, 10Nm can be much. I tighten those with 8Nm. I have reduced by experience of stripped threads despite only 10Nm.

A K1 head I mounted last winter had rather rotten threads due to porous aluminum, all cam studs got time-serts. Can be tricky to get it absolutely 90 degrees so the stud will fit the tight sitting cam holder.

I have not seen problem tighten them to bottom, still a hole on the other side I could fill with JB-weld.
Stud could been mounted with long thread into head, shorter threads down, longer up thru the cam cap

[TheArchitect]

Thanks!

I got the thread sealer, applied it to the bolts, installed them until the double nuts started moving rather than the studs, with a torque wrench set to 6 ft/lbs. Never hit 6.

I didn't want to crank too much on the double nuts, it set the bolts in well, had the right amount of thread left for the cam towers.

I will think about the J-B Weld. Maybe just some honda bond? I would be worried it will weld the studs in. Although I suppose they dont need to come out really. I pulled them for painting and didnt think much of it.

[754]

When shipping or working on head, they sometimes get in the way...or worse bend,
 I pulled a few bent ones, I then had to go over the surface with a file, as material pulled up.
 This can easily occur if they are bottomed.

[PeWe]

When alu start to pull up, the thread is bad and stud coming up. That's how I have seen my broken stud threads in head and fixed with thread inserts.
The photo above might be a stud installed upside down with long threaded side down?