Hmm, I like that. The existing plug has a magnet but is too short.

I could chuck an M12x1.5 bolt in my lathe to shorten it and bore it for a magnet but at that price, it's probably not worthwhile.

EDIT: I just found Chinese copies for A$3 (about GBP 1.75), post free, on evilbay Ron B. VK2OTC
2003 L322 V8 Auto
2007 Yamaha XJR1300
Previous: 1983, 1986 RRC; 1995, 1996 P38A; 1995 Disco1; 1984 V8 County 110; Series IIA

LATHE??

why are you messing around with helicoils when you could make one of those extensions ? If you made it in steel then you'd have a hard time messing the threads up.... and a Tap and die will be cheaper than a helicoil too  Yesterday I couldn't spell Engineer... Today I are one!
Inventor of the 'Guide-o-Matic automatic wheel alignment tool'
Former long term L322 owner, Up/Down graded to a Classic Tractor!

Also if you can use a helicoil, and it's been done, what is stopping you just tapping it to M14 and using a bigger plug, or use that as the size thread for an extension and it will be stronger and you'll be able to get a bigger bore hole in it! Yesterday I couldn't spell Engineer... Today I are one!
Inventor of the 'Guide-o-Matic automatic wheel alignment tool'
Former long term L322 owner, Up/Down graded to a Classic Tractor!

I prefered the helicoil as it leaves everything as standard size but you are then screwing into steel rather than aluminum so it will be a lot stronger and wont wear out.
have a look at this thread for a similar issue as this was resolved by buying a longer sump bolt

http://www.fullfatrr.com/forum/topic42815.html?highlight=helicoil

Lathe? I'm not a trained fitter and turner, I'm an electronics tech. I can do simple stuff on the lathe but I've never tried thread turning.

Re going to a larger thread, I'm not sure how much "meat" there is around the hole. I've ordered a Chinese Helicoil set. Ron B. VK2OTC
2003 L322 V8 Auto
2007 Yamaha XJR1300
Previous: 1983, 1986 RRC; 1995, 1996 P38A; 1995 Disco1; 1984 V8 County 110; Series IIA

Lathe thread cutting for something that small I'd use a die and a tap.... And you say not much meat... a helicoil kit will be drill and tap to M14x1.5 minimum, could be bigger, might be M16x1.5...

Re. thread cutting on a lathe, you can get a die holder that goes in the chuck of the tailstock and holds the die nice and square, but it is equally possible to keep a hand held die square with either a chunk of something flat faced in the tailstock or you can often steady it off the toolpost.

Female thread is obviously a hand tap in the tailstock, but just leave it unlocked so it can side up the bed..and it helps to have the lathe in neutral and turn it by hand, I invariably end up using the chuck key to help turn the chuck.

It is possible to cut internal threads under power, but you'll need a spiral tap and a very low speed, most hobby lathes don't have enough grunt for this, well mine doesn't  Yesterday I couldn't spell Engineer... Today I are one!
Inventor of the 'Guide-o-Matic automatic wheel alignment tool'
Former long term L322 owner, Up/Down graded to a Classic Tractor!

p38arover wrote:

I've ordered a Chinese Helicoil set.

Forgot to add that there is nothing stopping you from making it out of steel

That brass one was just the first adaptor that I could find on the Quickvalve site.

If you were to make your own, you could either stay with M12x1.5 and give it a longer nose, or go up to M14x2, which is the standard size (cheaper) for the adaptor and M12x1.5 for the internal bit which would enable you to keep the std sump plug.
Going M14 also has another benefit, the tapping size for M14x2 is 12mm, so you'd only be drilling out the threads in the sump... I suspect that you'll have to drill the helicoil 12.5, if its M14x1.5 and 14.5 if its M16x1.5.. either way a lot more material to come out of the sump wall. Yesterday I couldn't spell Engineer... Today I are one!
Inventor of the 'Guide-o-Matic automatic wheel alignment tool'
Former long term L322 owner, Up/Down graded to a Classic Tractor!

I have temporarily fitted one of these sump plugs. The thread is about twice as long as the original BMW plug. For the first time since I have owned the car, there are no oil drips off the sump plug.

http://www.smartoplug.com/



I did the change without draining the sump. I dropped a bit of oil into an oil drain pan under the car. Getting the thread started was a tad difficult, possibly because of the O-ring. It also took a fair bit of torque to tighten. I don't know if that was due to the O-ring or because it was cutting new thread.

I'll find out when I drop the sump to helicoil it. This Smart plug can't be used with helicoils. Ron B. VK2OTC
2003 L322 V8 Auto
2007 Yamaha XJR1300
Previous: 1983, 1986 RRC; 1995, 1996 P38A; 1995 Disco1; 1984 V8 County 110; Series IIA

The correct plug seals under the head with a copper washer and I previously used a bolt left over from my transmission rebuild with the integral rubber seal under the head as it was slightly longer and found some good thread.
The reason you had to torque it up so high is without the copper crush washer you had to deform the Aluminium instead which is why with the genuine oil filter you get a new copper washer as they are a one time use only ideally.

The seal on your bolt probably struggled to find a good thread or the seal passed through the threaded section due to its length or did you have the sealing washer as well shown in the picture which may have been too narrow compared to the normal copper washer?

I changed my oil yesterday and used the stock sump bung and new copper washer supplied in my helicoiled sump and all was good in the hood