manifold removal - stuck on oversize stud

[JonE]

any thoughts on a next step?

(Ruby) manifold all loose and nuts off. 

One nearest the rad is oversize and its obviously stuck, as when you waggle the manifold, the stud waggles/bends too. I can get a mm of movement from the block/head, levering with a jemmy bar between head and sidedraft inlet manifold parts. Rest completely loose.

I've taken off the fan/dynamo housing to allow wooden drift from behind onto the manifold outlet end, whilst waggling.
No joy with the amount of force presently applied...

Tried some heat around the stud, but no joy.

Don't want to disturb block. But also tried removing stud with two nuts next to each other, but that didn't work either.

[Andy Bennett]

I had exactly this with a head stud. Tried every trick, including hanging the car from the garage roof by the head. Nothing would release it from the stud. Had local A7 expert around to retry all tricks.

Eventually we got it moved by about 2mm t slip a hacksaw blade in and cut it off under the block, then drilled it out in the block and helicoiled in situ.

Sorry not the solution you are looking for.
Andy B

[Chris KC]

Jon,
I doubt I can add much to what you've already thought of.

Is it possible to run the engine so as to get it properly hot?

Could you remove the other studs so that the manifold could be rotated around the seized stud? (if nothing else it might create a small gap for a saw blade or levers).

Can you pry the other end of the manifold away from the block enough to insert a fulcrum of some kind (screwdriver...) between manifold and block, then whop the opposite end back against the block? i.e. use the leverage of the manifold itself.

Grip it with a stud extractor (I mean this kind of thing https://www.lasertools.co.uk/product/0296) and see what gives first?
I'd be frightened of doing a mischief to the block...

Failing that I suggest you need to set up a drilling guide - saw the stud off flush with the manifold, locate a guide on the next two studs, use it to centre a drill while you drill out only to the depth of the manifold, which ought to liberate it; you can then work on removing the remains from the block (a similar approach, but on the bench perhaps).

[Pricey]

Jon

When I hit similar on my Ruby with head studs I found that plumbers freeze spray in conjunction with a judicious application of heat prior to spraying the stud worked a treat.

I heated the stud and surround area then using a short piece of metal tubing over the stud spraying into the tube to cool the stud rather than what it was stuck into then went back to the double nut way of providing leverage. The extreme cooling allowed the stud to break free of the corrosion holding it. Some took two or three attempts but I removed all but one this way.

Worth a try.

[JonE]

Thanks all. I haven't tried using the jemmy as a lever and clouting the other end so perhaps that first. I didnt want to use a pry on the gasket faces but there is a good lever point between the inlet manifold part and the head.

I also hadn't thought of taking all the other studs out more because I wasn't sure how to do it. (And that if they work, don't disturb 'em!)

Ah well, some ways forward to try... and I suppose it wouldn't be cricket to put an angle grinder through a Ruby manifold, would it, just for a quick fix? I had been thinking that I would drill out the manifold hole there anyway to give it a bit more slack when reassembling, assuming I leave that larger stud in place if it survives!

[Hedd_Jones]

Given its the front end you can put a piece of wood against the exhaust flange and knock the bejezus out of it with a course persuader. Otherwise a 0.75mm slitting disk would be favourite. Then drill him out

[JonE]

ok. well on a scale of 1 to bejesus, I probably only got to a 4, thinking of the manifold breaking.
So it's not going to beat me...

[Chris KC]

I wouldn't worry too much about the manifold, but there's not that much metal around the stud, specially if it's O/S. Just saying.

[JonE]

ok, perhaps I'll start with the 7 quid freezing spray, as the Screwfix reviews are pretty good...

[jansens]

With stuck, partly broken studs I've had success making up a flat steel bar with a hole drilled half way along to fit over the stud. Put the bar over the stud so the top of the stud passes through the hole and then MIG weld them together. The heat from the welding usually breaks the stud free and the bar lets you turn it out. The danger is if it doesn't work you will shear the stud as you try turning it.

It works well for studs that are broken almost flush.

Simon