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Heater valve problems revisited
Posted: Wed Nov 02, 2011 8:35 pm
by GPO_Van
Hi all
There was a heater valve string that I read here when I had first got back into Moggy’s, (
http://www.mmoc.org.uk/viewtopic.php?f=4&t=28380)
I had the same trouble and had to grind off a bit from the side of the valve nearest the rocker cover so that i was able to get the rocker cover off.
I had to fit a new valve some time later and this was the same size as the original, needing the same grinding as the one I took off.
I have just changed the valve on another engine, the new valve is the same size as the last one I bought (both from BM) but the original old valve is smaller on this engine (original condition ie not ground down both engines 1098cc) rocker cover on and off no problem, new valve hell of a struggle so I have ground the new one down, See pictures.
The new aftermarket components are NOT the same size as the originals.
Pictures had been asked for in the other string but none appeared so I’ve taken some of my difficulties.
Reg[frame]

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Re: Heater valve problems revisited
Posted: Wed Nov 02, 2011 10:00 pm
by simmitc
I agree with you entirely, and have found the same problem over a number of years. It's the same old problem that modern components are not manufactured to the same specification as the original. The problem is that no matter how much you complain and send parts back to the supplier, they all have a stock that they are not about to scrap, and every replacement you get is wrong. It shouldn't be the case, but grinding seems to be the only answer.
Re: Heater valve problems revisited
Posted: Thu Nov 03, 2011 12:46 am
by mike.perry
I fitted an adapter plate on the bottom of mine so that I could turn it to the correct angle. It is on a 1275 head but the principle still applies.[frame]

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Re: Heater valve problems revisited
Posted: Thu Nov 03, 2011 6:34 am
by Declan_Burns
Those repro valves are rubbish. I had one and it didn't last long. The mini valve is better and the photo shows a similar adapter, as Mike has mentioned, to correct the angle for 12G940 heads.[frame]

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Re: Heater valve problems revisited
Posted: Thu Nov 03, 2011 8:23 pm
by simmitc
Can anyone point to a supplier and part number for the adapters and Mini valve, they look like a good idea, but the only Mini valve I can find is very angled. Thanks.
Re: Heater valve problems revisited
Posted: Thu Nov 03, 2011 11:39 pm
by mike.perry
The old taps on the earlier A Series screwed in to the baseplate. I used some spare base plates and a threaded tube to make the adapter
Re: Heater valve problems revisited
Posted: Fri Nov 04, 2011 6:42 am
by Declan_Burns
Read through this thread.
http://www.mmoc.org.uk/viewtopic.php?f= ... ve#p313966
If you want to use the angled and better mini valve you may have to DIY it. The photo below shows the principle which was the adapter that I made up to correct the angle for the 1275 head and the straight valve. The second angled section in the photo above was made up later when the repro valve packed up (which didn't take long!) and the mini valve was fitted. Very simple to make. Flat bar 3mm drilled and filed for an interference fit, copper pipe 1/2" and sweat solder it together then paint. Best part of an hours work and use the old valve/paper gasket as a template.[frame]

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Re: Heater valve problems revisited
Posted: Fri Nov 04, 2011 8:58 am
by bmcecosse
The early simple manual 'tap' is easy and neat - and on later Minis a simple stub pipe with no tap was fitted. Strangely these sell now for a LOT of money... The tap should never be closed anyway - keep the water circulating even in summer to prevent blockage and to assist cooling the back end of the engine.
Re: Heater valve problems revisited
Posted: Fri Nov 04, 2011 4:11 pm
by Bazzalucas
I have the OP's setup. I manage to get the VC off and on by turning the engine until the # 4 cylinder exhaust valve is fully open, the lifting the front end of the VC until it "slides out". There's just enough room.
Re: Heater valve problems revisited
Posted: Tue Nov 08, 2011 5:43 pm
by GPO_Van
Hi
After reading the different methods of constructing a raised heater valve I decided to use the bases of two old valves each with a section of the hollow shaft left on so as to join together and solder them together similar to those shown by Mike and Declan.
After cutting the two bases off I realised that on my engine, by cutting the tube off one base and using as a spacer I could lift the valve high enough that the rocker box does not catch on the valve.
Ye haa,

it worked
Thanks
Reg[frame]

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Re: Heater valve problems revisited
Posted: Tue Nov 08, 2011 6:49 pm
by lambrettalad
hi just fitted one from the minor center ,oldbury,fits like a glove

, and hopefully going to work for ages ?

Re: Heater valve problems revisited
Posted: Tue Nov 08, 2011 8:06 pm
by bmcecosse
Neat solution Reg!