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MG Midget and Sprite Technical - Cooling System Drain Plug Mk III Midget

I have to order a replacement bottom radiator hose and I wondered if anyone knows if the drain plug in the cross pipe, ARA 1618 could be replaced by the drain tap, 88G291, from earlier models? My guess is no, but it seems an obvious improvement if it is the same thread.
As always, any thoughts will be most appreciated.

Ray
Ray Rowsell

I haven't a clue but personally I wouldn't bother. If it is the same diameter then the tap part will reduce the orifice opening so slowing the emptying from there. Also a smaller aperture would mean that smaller pieces of any crud/muck/debris would block it easier and you'd be fiddling about with a thinner piece of wire to clear the blockage than the full aperture now (not that you'd have any crud/muck/debris in your system of course).

Then do you trust a newly modern made part or get an unknown s/h part that may not have been regularly used to stiff and perhaps already crudded-up (technical term). Often with those you can end up having to spanner them out anyway, thus negatinting the whole point of the tap.

Used to have one of those on each side of the V8s and you'd gingerly turn the wing piece and they'd fully turn - but no coolant came out.

Just consider yourself lucky to have a drain plug on the crosspipe and that it's removable.

You are of course to be highly commended for thinking in advance of future service work from the good book - I put here one gold star on your thread for all to see. :)
Nigel Atkins

Nigel,

Good points, well made. I was looking for the best of both worlds - the ability to remove it when required, e.g. for a full flush and the ability to easily open the system, low down, without needing a spanner. Anyway, I have ordered a new hose and I will live with the plug.

I don't know if it's good luck, good maintenance or regular use most of the time, but (says he touching wood!) I have not experienced any overheating problems in my 20+ years of ownership.

Gold Star!! I haven't had one of those for a long time.
Ray Rowsell

A certain person formerly of this parish, made up a new cross pipe using standard copper solder ring fittings, with a 15mm branch from the middle, and controlled by a drain tap. One advantage is the drain point can be extended forward and clear of the chassis cross member so that drained coolant can be caught, strained to remove debris, and reused.
He posted photos of it which would explain better. It will be in the archives somewhere
GuyW

Ray,
you sound like a gold star owner, view the gold star with pride (but don't lick it or try to eat it).

When I saw your reply like Guy I thought of of a certain person's adaptation, I'd forgotten all that was involved. It was a great and proven idea but the drain had some of the ugliest combination of fittings possible.

Having far, far, too many times drained down from just removing the bottom hose and have the coolant run all over the dirty chassis and find their own trap areas to drip from later I'd love a central controlled drain point but I always hope the previous drain was the last!

I guess the standard cross pipe is too thin walled to go up in size too much to fit a larger fitting. I'd want a tap with a nozzle that I could connect a hose to so that I could easily collect the coolant without spilling any.

For partial drains I syphon out of the radiator.

Nigel Atkins

Guy,

Your post unlocked that area of my brain where lots of information (some useful!) is stored. With your prompt, the picture of our friend's creation came back into mind, as Nigel said, ugly but practical. I am sure that could be refined and made pretty without too much effort. It would be nice to control the output by using a tap. My memory is notoriously fickle but I seem to remember the tap I was looking at worked well on the Morris 1000 in which I learnt to drive all those years ago.
Ray Rowsell

Ray,
are you thinking of the cylinder drain tap that came before the plug and washer in Spridgets too, again I don't think that'd help much and you can't fit a hose to it.

Drain Tap-Cyl Block - 3H576 - https://rimmerbros.com/Item--i-3H576
Nigel Atkins

Nigel, the block two on my 1098 engine is similar to that Rimmer Bros. one, only it does end in an outlet designed to take a push-fit length of hose.I

I don't think LS's plumbing pipe device was that ugly. It certainly looked much better once painted black. The ugly part was the 15mm branch outlet and tap which perhaps could have been improved on but that part is down beneath the radiator and pretty hard to see anyway.
GuyW

Guy,
perhaps the thread on the block accepts various sorts of old plumbing taps, like the heater tap on the cylinder head, sophisticated they ain't.

It was the branch outlet and tap on he-who-can't-be- named's pipe device that I was think of as the ugly part, even if it can't be seen it could have been smarter and perhaps smaller but I expect it was done with whatever was available or very cheap (was it on the midget he sold). As I remember it, a c/h drain plug on a slip fitting, short length of pipe, on to a reducer, on to a tee, too many fitting and too ugly - but the idea was proven and good. And somehow I think painting it (white originally? IIRC) made it even uglier.

I believe photos of the device have been banned from the web as they depict such horror.

Nigel Atkins

Viewers of a nervous disposition be warned - in my next post I will be putting up the actual photos, sent to me through the ether, and they are even worse than I remembered.

He-who-can-not-be-named calls it "function over form" but it can't excuse such brutality.
Nigel Atkins

A different "slaughter" of fittings to what I remembered.



Nigel Atkins

But I did remember the white paint correctly.

The original thread is in the Archives titled 'Crossflow radiator draining.' for those that want the fully gory details.



Nigel Atkins

Hi Nigel,

No, I was looking at the radiator drain tap that was fitted to pre crossflow Midgets

https://www.sussexclassiccar.co.uk/shop_factory_hazel/contents/media/88G291.jpg
Ray Rowsell

Ray, it's about the same size so may well be the same thread fit - but I don't think there'd be enough room to undo the butterfly bit.
David Smith

Hi Nigel,

No, I was looking at the drain tap that was fitted to pre crossflow Midgets

https://www.sussexclassiccar.co.uk/shop_factory_hazel/contents/media/88G291.jpg
Ray Rowsell

Ray,
we'd done and dusted that one earlier in first reply to thread, its the V8 style one, 88G291.

I hope you're not coming down with something.

Nigel Atkins

This thread was discussed between 28/03/2020 and 31/03/2020

MG Midget and Sprite Technical index

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