I have a 2.0 type IV from a 914 in my 912, it has the GA heads and Weber 40 IDFs. Today I was warming it up to change the oil and saw flashing from the intake manifold/head seal area when small backfires occured. Naturally I started to tighten the intake manifold bolts. On the #1 cylinder outboard nut, I felt too much play. I wiggled the stud and pulled it right out!
See the picture below. I was able to find more threads in the hole and thread it back in using 2 nuts so it isn't completely stripped. Only about 1/4" of threads came out with the stud.
What should I do here?
Click to view attachment
Full Version: Stripped intake stud
Looks like a heli-coil?
--DD
--DD
Whoever installed it backed the stud out because it was to short for the carb manifolds thicker flange. Try a longer stud to catch the remaining threads and if that doesn't work you will need to helicoil it.
BTW someone is bound to say helicoils suck and use a time-sert, yes they are better, but in this case there's little torque/load so a helicoil will work just fine.
BTW someone is bound to say helicoils suck and use a time-sert, yes they are better, but in this case there's little torque/load so a helicoil will work just fine.
That does look like a heloicoil that has came loose. That is also not the proper stud. It actually looks like piece of all thread. The stud has a non machined area in the middle and is longer.
Looks like a Helicoil? I say not. It looks like aluminum that pulled with the stud. Happens all the time with studs that are too short for the application.
The Cap'n
The Cap'n
In my experience, the aluminum threads that come out with the stud tend to stay on the stud. Makes the end of the stud look shiny and relatively smooth. Also, I think I can see gaps in between the threads, which make me think it's a coil.
Not that my experience compares to the Cap'n's, but I may be better at stripping threaded holes than he is.
--DD
Not that my experience compares to the Cap'n's, but I may be better at stripping threaded holes than he is.
--DD
QUOTE(Dave_Darling @ Oct 4 2012, 05:25 PM) 
In my experience, the aluminum threads that come out with the stud tend to stay on the stud. Makes the end of the stud look shiny and relatively smooth. Also, I think I can see gaps in between the threads, which make me think it's a coil.
Not that my experience compares to the Cap'n's, but I may be better at stripping threaded holes than he is.
--DD
When the metal was on the stud it was very smooth on the outside which made me think it was stripped aluminum.
Does anyone know the proper length for the studs that have the flat machined section and also where to get them? Pelican turned up nothing.
I believe intake manifold studs are M8 x 1.25.
Use a depth gauge to measure the bore, then add the thickness of intake manifold, gasket, washer and nut to come up with the length you'll need.
Use a depth gauge to measure the bore, then add the thickness of intake manifold, gasket, washer and nut to come up with the length you'll need.
Time-serts and heli-coils both require full thread engagement to prevent insert failure. I have seen each break when only a portion of the threads were engaged.
Time-serts are a cast alloy and heli-coils are wire. Each has certain frailties that require consideration.
Yes.
Time-serts are a cast alloy and heli-coils are wire. Each has certain frailties that require consideration.
QUOTE
Does anyone know the proper length for the studs that have the flat machined section and also where to get them? Pelican turned up nothing.
QUOTE
intake manifold studs are M8 x 1.25.
Use a depth gauge to measure the bore, then add the thickness of intake manifold, gasket, washer and nut to come up with the length you'll need.
Use a depth gauge to measure the bore, then add the thickness of intake manifold, gasket, washer and nut to come up with the length you'll need.
Yes.
This is a "lo-fi" version of our main content. To view the full version with more information, formatting and images, please click here.