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MG MG Y Type - HELICOILING OIL DRAIN PLUG ON AN XPAG

Guys,

It is possible that this has been covered before. However, I would appreciate your thoughts and comments on the following. Yesterday I was undertaking an oil and filter change on the XPAW engine (late YB's, TD's and 1250 TF's) in my TA. Whilst I recognise that this is an item that perhaps ought to be addressed to the TA-TB-TC site it is nontheless one of commonality in the engines in YA's. YT's and YB's which of course you are all aware of.

Anyhow, after that little discourse I will return to the efforts of my simple task. An oil change is something I have done using a good friend's pit over the years. Sadly he has died so this facility is no longer available. Therefore. it was jacking up the car and placing it on axle stands and easing myself beneath to undo the sump nut. Dead easy I thought.

However, the simple job became a complete pain in the ar*e as I just could not undo the nut and had to resort to a torque wrench. The carefully placed receptacle to catch the oil sadly only took about 75% of the contents and the garage floor was a pool of warm oil! Anyhow, I overcame this and cleaned the nut and washer and replaced them ... but as I gently tightened the nut there was that horrible feeling that I had probably stripped the sump thread. I tried plumbers tape on the nut thread but that was of no value.

So I am now at the stage where I will probably have to drop the sump and then get the thread helicoiled. Has anyone any experience of this and the do's and dont's around it. It's not a job that I intend entrusting to myself as I will probably make matters worse. I have ordered a new nut and washer from Moss in the vain hope that this will provide the answer but I just dont think it will.

So any thoughts are welcome.

Sincerely

Jerry
J P BIRKBECK

Jerry

Are you sure you have stripped the threads?

Hopefully the car is still empty of oil so undo the nut. If you have pulled the threads then there will be slivers in the brass nut as it comes out. Once out, remove the road wheel on the left side (assuming the sump plug is on the left as it is on a Y) so you can get a nice angle on your belly/tum. With a good flashlight (you would call it a torch in English [LOL!]) examine the threads visually, then stick your finger in and GENTLY feel the threads. I emphasise GENTLY as if there are threads sticking you dont want to end up collecting them in your finger as that will hurt!!

As to the mechanics of actually helicoiling it, it is only a short thread so it will be difficult. I think (from memory) the maximium oversize is about 1/64 to tap out the hole but I can check that if you like with my engineering shop. In fact, let me do this. Let me pull a sump plug for you and take it in and ask what size helicoil you will need and get back to you.

Later,

Paul
Paul Barrow

OK Jerry

You will need a 1/2”BSP 14 TPI helicoil.

Word on the street is "good luck finding one that size" but if you encounter problems in the UK let me know and I will see what can be located here in the US but I wouldnt hold your breath on that because of the BSP.

Another solution, besides trying to find a sump that someone else hasnt messed up in some way that is "cheap" may be to TIG weld the circumference and then have it centered and drilled back out to the original size.

Places you could try are:
1) http://www.workshopping.co.uk/category/helicoil-type-inserts-bsp/1866/ or
2) http://coventryvoc.co.uk/tool_scheme.htm
and there may be others on this Google search - http://www.google.com/search?q=%C2%BD%E2%80%9D+BSP+14+TPI+Helicoil&sourceid=ie7&rls=com.microsoft:en-gb:IE-SearchBox&ie=&oe=

Paul
Paul Barrow

Jerry

A couple of extra thoughts for you:
1) When you go to order the helicoil kit ... double check with them that it is 14 TPI (turns per inch) with the supplier though as you dont want to find out it wont work after you get it.
2) Helicoil kits and fitting tool sets (including new tap for the coil ... and you will need that) arent cheap. Ensure that you are getting everything you need to fit it succesfully and not just the coil.

Paul
Paul Barrow

Hi Jerry,

Rather than helicoil the hole it would be easier to re tap the hole 7/8"(11 TPI) or 1" BSF (10 TPI) The existing 1/2 BSP thread had a tapping size hole of 18.75mm wit h a max hole size of 21mm.
A 7/8 BSF thread has a tapping hole size of 19.75mm with a max hole size of 22.25mm
A 1" BSF thread has a tapping size of 22.75mm with a max size of 25.4mm.

You can then use a shortened BSF setscrew with a copper washer for the drain plug.

It would be much cheaper as well.

Cheers Chris
C A Pick

Thank you both Chris and Paul for some detai and suggestions which is much appreciated. Thanks also to Richard Knight who phoned me up and kindly offered me a 4/44 sump. He then followed this up with 3 e-mails with photos.

Again very useful. However, the sump fitted is a fimmed version which I think was found on the TD and 1250 cc TF. The guy whom I bought the engine from had converted the engine externally so that it was a replica of the XPAG.

looking at Richard's photos the sump arrangements are entirely different but I very much appreciate his thoughtful offer.

I think I'll follow Chris's suggestion, anyhow I must thank all of you for your help and guidance.

Sincerely

Jerry
J P BIRKBECK

Guys

Thanks for all your help and suggestions which are much appreciated. I gather that there is of course a BSP (British Standard Plumbing)used for the application of pipework and connections.

I followed this up with a local mechanic and after measuring the diameter of the plug found a suitable fitting that matched the thread and provided a secure fit into the sump. This was a coupling into which a shorter plug was fitted which provided a seal for the system.

I ran the engine but have yet to take the car out on an extended run. However, no leaks to date. I took a photo of the fitting but it was not very good - so will try again.

All the best

Jerry


J P BIRKBECK

This thread was discussed between 22/07/2011 and 27/07/2011

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