Help with Engine bolts

[amalgamated users from prior forum]

Message originally posted by: Andy Dane
OK, between my brother-in-law and I we managed to shear off one of the 4 bolts that holds the Marlin mounting bracket to the engine.

I drilled it, added a screw extractor and snapped that off. Cutting a long story short this bolt has been killing me for a week and a half and I have finally got it out BUT the hole it was in is now significantly larger and is uneven.

So do I try and make a nice round hole (maybe 12mm?) and add a thread?
Do I ignore the hole and try to make up a bracket to "stretch" the marlin bracket across to the next hole (about 2 inches away)?
Is there a super metal glue (welding?) that would help ?

Answers on a forum please!!

The engine is a BMW E36 325 - pictures available when I go back into the garage to take some...

Andy
bmw.sportster(at)virgin.net
www.marlinsportster.co.uk

[martinclan]

Re: Help with Engine bolts

The "proper" way to do it is to fit a Helicoil. You canbuy the kit for this from namerick but it aint cheap. an M10 kit is about ?32. Alternativley you could just drill the hole out to the next size up and re-tap it. For a 12mm thread you need a drill size of 10.2mm. Be carefull though that there is enough meat in the block and you are not near an oilway. Also be carefull not to snap the tap off in the blcok or you will be back to square one. If you unsure about doing it yourself you may find a local motor engineer that will make a house call and do it.

How did you get the bolt out in the end?

Robin

[amalgamated users from prior forum]

Re: Help with Engine bolts

Message originally posted by: Andy Dane
I drilled round it with a small drill, then got progressively larger until I could pull it out with pliers. Broke 5 drills doing it too!