rgh0 wrote:Take the head off if you wish .
i would not and it is not necessary. You say the drill went all the way through before it broke ? The get a suitable pin punch and tap the drill out and keep drilling. i dont see the problem ?
Hi, Rohan. Pardon me for not understanding, but how do I tap a drill out from above with a pin punch? I'd be driving it further in, surely. What I didn't say is that I attacked it again with a different drill but the result is a bowl with no part of the jammed bit showing.
As to removing the head, it is on the to-do list anyway because I have quite a bit of oil coming out of the timing chest gasket.
If you cant do that start another hole beside the drill that broke. I assume you are actually using small drills of maybe 2 mm size currently and not trying to drill out a 6 mm stud with a 5 mm drill in one go? Hard to imagine you managed to break a 5 mm drill.
It's a 3mm bit I think. I had been drilling with a 5mm bit but it was off centre so I tried with a smaller bit. I only drilled a couple of mm down with the bigger bit, so I think there is still some undisturbed thread.
Another alternative get a dremel if you dont have one with a small carbide bit and take out the bolt and drill carefully. Or at least cut a slot in the top of the bolt so you can get an impact driver on it and head the allow cool the bolt hit it with an impact driver to see if it moves.
I have a Dremel but no suitable tip. It's one of those "get 150 accessories" type things that has very little of what you actually need. For example, there is one drill bit (3mm) and one reaming bit. The carbide tip you are talking about, is that a drill bit or a stone grinding tip?
Patience and care is what it takes. i would be more worried about a machine shop butchering the head personally.
I think I have demonstrated that I do not possess vast stores of patience.
You're right about the machine shop, so I might have another go at it with the Dremel.
What you replace them with is up to you but read a few good books on bolted joint design first before you start carrying out advice on modifications to bolted joints you may not understand the consequences of
I think it is fair to say it's not a safety critical joint. To my mind, if a bodged up external bracket (with a degree of flex in it) is able to exert enough pressure on the housing to form an effective seal at operating temperature / pressure, any replacement that can do the same should suffice. But.. I'm not an expert!