MG-Cars.info

Welcome to our Site for MG, Triumph and Austin-Healey Car Information.

Recommendations

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG TD TF 1500 - Gas tank plug threads

Does anyone know what the thread size for the lower fuel tank plug and the thread for the second hole for the fuel take off/strainer. I've got paint in them and I need to get a tap to chase the threads.
Many thanks
Rod Murray 54 TF
Rodney G Murray

There are a few posts in the archive Rod & they all suggest 3/8" BSP parallel. Cheers
Peter TD 5801
P Hehir

I can send you a loaner tap to clean the threads.
Len Fanelli
Abingdon Performance
laf48@aol.com
914 420 8699
Len Fanelli

I recently bought a variety of plugs for the gas tank. My tank has two outlets. One to feed the engine and the second had a pinched off piece of copper tubing as a plug. I am replacing that with a new plug.

16mm
3/8BSP
Tapered
Mort 50 TD

I went a slightly different way Mort replacing the original plug with an adaptor to take a radiator drain cock. If I ever need to drain the tank or even get a small quantity of petrol it is now a really simple task. Cheers
Peter TD 5801
P Hehir

Don't use a radiator cock or any other tap or valve that is not intended for petrol or you may find in time that it leaks, especially if it has some kind of rubber seal. Buy a type that is intended for use with petrol. They are obtainable from outfits that supply parts for stationary engines, agricultural machinery, etc.
Dave H
Dave Hill

Correction,
I got the following email from Len Fanelli

"Hi Mort, BSP not tapered BSPT.
3/8" not 16 MM
Best
Len
Only the brits would have straight pipe threads!"

He is absolutely correct.
I got my info from a salesman at ---- ------.
But I just double checked and Len is right. At least I got the thread right it is BSP but it is straight.

If you are ordering a plug take note. They were not expensive and I wound up ordering from 3 or 4 sources. Only one was usable. It has a decent flange to apply pressure on the washer. The washer I am using is one of those compressible double ringed types (don't remember what they are called).

Peter,
Careful of how far down the valve hangs. It is possible that something in the road might hit it. That is why I am going with just the plug.

Mort
Mort 50 TD

Thank you for the size info and thanks to Len for the kind offer of the loan of hits, however; they can be had locally for about $14 so I'll go that route!
Best regards
Rod
Rodney G Murray

In regards to Peter's valve, I had the same idea but never implemented it (it was discussed at length in at least one thread, though). I purchased a cheap Chinese valve but discarded it immediately as not being reliable enough to use. I researched aviation petcocks because with a gas tank drain valve I think you need something highly reliable and lockable (either with a wire or some other locking design) or else you run the risk of having a small rock thrown by the tires empty your tank for you...
As I couldn't find any BSP aviation valves and would have had to find a 3/8 BSP plug to install and drill and tap that for a 1/4 aviation valve, I eventually abandoned the idea. I also didn't much like the idea that any valve would have to project down some more, into the road, which wasn't a good idea.
I'd be interested to hear more on what valve you installed and see pictures, Peter!
Geoffrey M Baker

Mort & Geoff. The tank thread is definitely 3/8" BSPP. Yet to fit the tank so I can't comment on how far down it will hang or the likelihood of it being inadvertently opened, though the action is very firm. It's either a plated, (or more likely), a stainless radiator drain cock & came from a YT. See pic. Can't find the thread you refer to Geoff but I do recall it & also having some difficulty in finding an adaptor with suitable threads. Cheers
Peter TD 5801

P Hehir

"Only the brits would have straight pipe threads!"

Straight BSP threads are used when there is a shoulder for the valve AND WASHER to bear against. Tapered pipe threads should only be used where there is no such shoulder and thus with no washer.
Lew3

Spruce Aviation has valves specifically for av gas drainage.

I drilled and tapped standard tank drain plug.

I think somewhere in archives there are specs and a drawing.
R W Hinton

This thread was discussed between 21/02/2016 and 29/02/2016

MG TD TF 1500 index

This thread is from the archives. Join the live MG TD TF 1500 BBS now