Well...my exhaust threads were stripped and after taking it apart I realized it was already helicopter coiled and that's what stripped. So I decided to put a time sert type thread insert in but, it was kind of a long insert. So when I went to drill the larger hole, I accidently went all the way through into the head. Obviously this is bad but, how bad? I assume if u put in a newbolt and maybe some silicone around it, it should seal and keep oil from coming out...will this fix it or have I caused a much larger problem then I'm thinking?

Yeah you're going to want to replace that head.  Unless someone knows of some magic way to fix it.

Edited January 5, 201412 yr by Vegablade

Well if put the bolt in with some high temp silicone rtv would it seal and work for a while or is there a major risk of damage with the hole in it? I've never had this happen so I'm not really sure how having a hole in the head affects the engine. It seems to me if its plugged up with the bolt it shouldn't matter that much...but I'm not sure

If you've just drilled into an oil gallery it should be alright.  It's at least worth a go - if it starts leaking profusely then swap the heads.

My thoughts would be that you've possibly drilled into the exhaust port, in which case there's no need to stress, there might be a bit more turbulence in the exhaust gas but nothing that's going to slow down an EA82 any more than an EA82 already does

 

Use your silicone on it as it should only help with the seal.

Cheers

Bennie

Yes, it is into an oil gallery...the hole required for my thread insert was pretty big, 16mm, so I can actually stick my finger in it and feel the spring on the rocker. This is an ea81 on a brat by the way. About an ounce if oil came out when I drilled the hole.

It's worth a shot. Just make sure you try and clean out as much of the metal shavings as you can. And try to get a bolt that is the perfect length, not so long that its way up in the oil passage, not so short that is not grabbing all the threads.

I had something like this happen a while ago.  I used some Loctite thread sealer and it didn't leak.  Make sure to clean the threads with brake clean (acetone) really well.  You could use a stud there so you don't have to mess with it in the future.

That's a good idea, a stud with the permanent loctite.

I would drill & tap a 16mm bolt cut head off insert a stud.

Go with the stud like "NUT" said....

Go with the stud like "NUT" said....

APN  is a better short 

The "real" fix would be to have the head removed and have a welder fill the hole then redrilled to the original (or even new size).

 

However, what I would do is find an allen-headed plug, sink it as deep into the hole (with thread sealer) as it will go, then locktite the new stud in there on top of it. I think this way will give you the best chance of sealing up that oil galley.

Howbout install a small plug and hilicoil below that aplug that's 1/4 inch should still leave you room below

I did a similar repair on a motorcycle head many years ago . I threaded the hole with a tapered pipe thread and put an aluminium pipe plug in tight , cut it off flush , drilled and tapped for a new stud. Maybe a brass plug would work also.

I would use jb weld putty type to back the hole. I wouldn'y use silicone if it were an oil passage. JB will hold up to exhaust temps

fixed yet ?

 

are you lucky enough to have the other pair of threaded holes available, such as not have the cast iron air injection pollution control bolted in using all four threaded holes?

 

A fix I have seen done, once you plug the oil hole, is to cut the header pipe right through and rotate it 90 degrees and use the previously unused holes ast he new exhaust stud holes, weld the exhaust up in 90 degree twist position

Edited January 8, 201412 yr by jono

Hey guys,sorry I didn't get back to you. I was driving out to Texas. So the short answer is I fixed it and so far it has held perfect without any leakage. I took my thread insert(ez-lok, sort of like a time sert) and I coated the threads with rtv high temp copper silicone which is supposed to resist oil and high heat(I also used the rtv to make gaskets for my exhaust headers and it has worked fine too). Then I installed the insert then took my bolt and coated the threads of that and installed it. I have to say those ezlok inserts are awesome. No special tools to install it and I was able to really torque the bolts down. I feel like its a really solid fix but I think I'm going to order studs and install those in the ex loks when I pull the exhaust bolts for a semi indestructible permanant thread fix. Anyone looking to for a fix for the aluminum threads should check the ezloks out. Way cheaper and more solid then helicoil and no special tools. And the ez loks are 16mm threads outside and 10mm inside. Solid hardened steel, precoated with red loctite. Just an fyi. Thanks for all your responses, if at some point soon the fix fails I will update, but, 1200 miles and its solid so it seems to be a good solution.

Another way to fix it is, call The Doctor's phone number, have him take you back in time in the TARDIS to when you broke the bolt. Now here is the tricky part, you have to stop yourself from drilling through the head without you seeing yourself, I'd recommend an ape suit or getting The Doctor to do it. Then go forward in time and this thread wont even exist cuz it wouldnt be a problem!