2 stud holes have been threaded on the head where the exhaust manifold is bolted up to. obviously getting them drilled and taped will be my best option but wondering if i could be get by with some exhaust sealent or cement?, reason being.. im on a tight budget
and also, a ruff price on drilling and taping the studs in?
thanks in advance
When you say they have been "threaded" you mean they came out ?
or the threads are stripped ?
I had 3 go on another head I put together, took me 15 mins per hole to
drill and tap in a helicoil cost me about $30 for the kit and I still have a
few helicoils left.
As an extra, I put in a little high temp sealant before driving in the helicoils
and also centre punched the ally around the helicoil so it would make sure
it was held in nice and tight, none of them have budged since...
Some original photos have not been recovered yet.
mmmm, Studs there for a reason I think, less wear and tear on head threads
if you use studs given the torque and Ally's propensity to gall and cold-form
into the threads... !
Quote:
Originally Posted by MaD_WoG
ive got bolts in mine, not studs MUCH better
Yeh i agree with mike.. studs are there for a reason, and if there installed correctly theres nothing wrong with them.
Dont be cheap and nastywith that goo ****... get a tread taping kit from supercheap or something. sounds like the thread just needs cleaning out. no need for a heli-coil.
Not sure what rusty577 means re the kit but there is a teflon tape that
plumbers use to take up slack in the threads and seal against leaks, essential
with gas fittings etc.
The prob is that the ally is not particularly strong (in that location given its
exposed to heat cycling) and sometimes when a stud comes out it takes a bit
of the aluminium thread with it !
So next time you drive in a stud it cant take much torque because there is
less thread to grip it which means greater chance of stripping
Having said that you can take studs out but first put some cotton wool
around the area where the stud butts up against the ally and soak it with
vinegar and leave it for a couple of hours so the vinegar (acetic acid) soaks
into the thread in the head. This softens the interstitial layer of where the
aluminium oxide becomes chemically bound to the rust from the stud. Can
use the same method to take out the air bleed screws from the cooling system
in the air gatherer and inlet manifold...
Heli-coil is a steel coil that looks like a spring but is cut in such a way that it
forms a good thread when inserted into the aluminium, you first cut a thread
to take the helicoil with a simple tool then thread the helicoil in with the
other end of the same tool (usually) - other than that "google is your friend"
Some original photos have not been recovered yet.
Use helicoils, they are cheap and actually make the bolt/stud hold and pull up tighter
Studs are used because they put far less stress on the threads that the stud is screwed into, They pull up more even and tighter
Quote:
Originally Posted by Wilko16
Use helicoils, they are cheap and actually make the bolt/stud hold and pull up tighter
Studs are used because they put far less stress on the threads that the stud is screwed into, They pull up more even and tighter
Yes agree fully with that, pulling up tighter is a good thing because there is
chance some slack can develop if you just rely on bolts that can damage
threads - another good reason for sticking with studs, otherwise it can result
in exhaust leak and some of that will get drawn into passenger compartment,
long term incremental exposure to Carbon Monoxide is not a good thing, can
make you also nod off on long country trips.
