Using a STOMSKI exhaust jig

I was waiting for some bits to arrive for my engine, so I thought I'd have a play with the Stomski jig and see if I could remove some broken bolts out of the heads. This head had two broken bolts in it. Exhaust manifold surface cleaned up and the heads of the bolts levelled off with the grinder. Jig attached at two points, using a pair of the inserts to line up over the broken bolts Pilot holes drilled View of the pilot hole. Larger drill used to remove the rest of the stud. This is what it looks like after it has been drilled out. Any parts which can be picked out with a pick were, Than I ran a tap down the hole to clean it out properly. I did a total of five of these over three heads, no problem at all. The drilling takes a bit of time, but then it is going through about 20mm of steel so it is to be expected. I did a short video as well so I'll probably add then when it has been edited. MC

Nice. How hard do you think this would be with the engine in situ laying on your back under a car on axel stands? When you say that the drilling takes some time, on average how long did you spend drilling on each bolt approximately? It's a task that I'll have to address one day.

Good job @mistercorn Fortunately, my heads were sent away on my last engine and done for me. It took them several days as it appeared that previous owner(s) had bodged a repair and threads were not square to the mounting face. Time will be taken removing old exhaust system. As long as you have space below the car, ideally on a garage ramp, it should not take much longer using the jig. I have another set of heads to work on a bench. The bolts are in poor condition, but most likely I will have them sent away along with other work required.

I have my car on axle stands, silencers and cats are off, manifolds next but probably won't get time to carry on with it till the new year now :roll: Nice little write up MC :thumb:

What happens in the event all of the studs snap off, how would you locate and fix the jig? Nice job though MC

I think you would have to be very unlucky. Of the 6 sets of heads I have taken the bolts out of, the worst had 3 or 4 snap, andaround half of those came out with a stud remover. I ended up with 3 heads needing the jig, 2 with 2 bolts each and the other one with one. Based on the times from my photos, from the first photo to the last was just under an hour. The electric drill I was using was underpowered but was the only one I had to hand. The drills would benefit from being sharpened. MC

For those who prefer it in video format... MC

What stud extractor did you use? I'm now enthused to do mine engine in situ having purchased a stomski a while ago! Ian

I've done this job with this jig upside down in the rain under the car on axle stands. It was a miserable experience, but the jig is fantastic. It took two and a half days. I seem to remember only four of the twelve bolts undid and the rest snapped. Even if they all snap, the jig still works as it comes with fixings that screw onto the thred of the remains of the snapped bolt, as well as ones that screw into the threaded holes in the head that successfully undone bolts have left. You would have to have all of the bolts snap off flush with the head to find yourself with a real problem, and that ain't gonna happen. I used the same stud extrator as MC did in a previous video to remove snapped off studs but it didn't work for me on a single stud. The Stomski jig is a work of art and if you're doing this job on the car rather than the bench then I don't think it could be done without this jig.

Details on the stud extractor here: MC

Great information. Im in the middle of removing the manifolds from my TT and ive managed to get 4 bolts out and snapped one so id done a bit of research into the stromski jig. Good to see real world unbiased opinions. On the same topic, MC do you have any preference for slackening off bolts that are so badly corroded sockets wont grip the heads? Ive used Irwin sockets to get the 4 out but the rest are missing so much metal event they wont grip. Im thinking welding a nut on might be my only option.

Given my experience with the stud extractor I would be tempted to just grind the head off and then use that. Welding could well work very well though, the heat will help to release them. I might well have a full set of spare PPBB studs and k-nuts for a turbo as they weren't used for my build. I'll be looking to sell those on. MC

I've use twist sockets designed to grip on rounded heads. In fact I use them on most external bolts as I will replace them anyway. The problem with exhaust bolts are the stresses of normal use. The neck corrodes badly around the flange and will simply twist off like butter as the shaft will have bonded by galvanic corrosion - double whammy :nooo:

Noted, appreciate the advice. As for the studs, feel free to let me know how much you want for them, clearly ill be in need

When I did mine I had several that had no head that I could beat a socket onto, so I ground what was left away and then removed the manifold. Before using the jig I then ground another few mm off the studs in order to give the drill bits less to have to get through. My very worst one that I was able to beat a socket onto and turn, took an 11mm socket. Pretty amazing when you remember those bolt heads are 13mm.