Where can I find manifold repair studs ?

[Ian C]

I had to helicoil a stripped stud on my MkIII Supra back in the day. It remains the only time I've ever done it and back then I didn't even know the names of half the bits under the bonnet. It was slightly wonky as I had to use a manual t-bar tap while kneeling across the suspension turrets, but it worked for the rest of the life of the car. I had no metalworking experience and stil don't really. If I can have that level of success under such circumstances, what kind of chimp must you be to break a helicoil while installing it?

[trebor69]

I have used helicoil's in the past ....many years ago, for trying to repair motorcycle head to manifold joins (with varying results) ......the reason these two studs have given up is down to the manifold that I HAVE now decided not to use, the nuts all came off fine but due to the information I was given at time of purchase (about the 10mm clearance to steering column) and the lack of manipulation room, I had to remove the studs too to get the manifold on, that is when I found there was no clearance and it was rubbing ....so it was nuts and studs out to get the manifold out to heat up and persuade ......having taken it off four times now (each time the studs come out) I find that I have knackered two of them ........ The manifold is now clear and fits but I have now purchased a whifbitz 1st decat which is now on and will be staying that way ........I just hope to recoup some of the money I paid out for the 1st manifold now I have worked it into shape !!!

[trebor69]

I have two of these repair studs on the way now but will seriously think about other methods of repair before going ahead with fitting them ......I only have a driveway and basic tools.

[gavin.starr]

Helicoils for the win.

 

Ive used them for years. They really are a piece of P*** to install and are a hell of a lot better than oversizing you hole to suit a new thread/stud which is going to be going directly back into an ally threaded hole.

 

Also if you tighten in the stud propperly before you install your manifold it should never come undone again. Try locking two nuts together on the exhaust side of the thread and running it into the block to a set torque, undo the nuts, remove them from the stud and then install you manifold using some copper exhaust manifold nuts. Simples.

 

Gav

[gavin.starr]

Ive just done a repair on a cylinder head on a 125cc The spark plug thread was fecked, I needed an M10x1mm pitch around 16mm long.

 

Ebay come up with a kit at £7, and 5 longer coils at a cost of £2, Yea the kit is cheap and the tap wasnt the best, But I inserted the coil and the spark plug fits like a glove.

 

Gav

[Chris Wilson]

If you have to work on Nissan RB25DET engines Helicoiling exhaust manifold studs, and drilling out the flush sheared remains of the old stud becomes a way of life. Nissan made the holes in the manifold too small, and their centres are a bit off. as the cast manifold expands lengthwise the forces on the sides of the studs are massive and they eventually shear off. Helicoiling, fitting new ones, and milling out the holes so there is zero side load on the studs even when the manifold expands with the exhaust heat fixes them once and for all. You really need a jig with drill inserts to centre the drill bit in the stud to safely drill the old broken bits out. PITA of a job!

[jay200bhp]

Who are you calling a bell end then?

 

Any one who can "break " a helicoil!