Hello! The Forum
This is my first post to this forum and I was immediately attracted to the heading ‘Boiling Scott’ and I felt I had to add something, having lived with the problem for several years, a bit of a story, though of relevance to the thread. Bear with me, please.
Once upon a time, in early 1960 whilst stationed at RAF Kinloss in Scotland I’d purchased and as I recall, paid 30 quid for it from a chap in Dallas, a village located in Morayshire, an old motorbike with sidecar, a Scott. I’d never seen a bike like it and neither had anyone else in my ken but I needed the sidecar, increasing family. The ‘bike had lots of mechanical problems, including boiling every 15 miles or so. Tried everything to cure the boiling, mainly timing but to no avail so learned to live with it. The whole motorbike mechanically was a steep, steep learning curve for me.
Enough preamble, cut to the story:
I’d had the ‘Boiling Scott’ several years, and used it every day, then I had to drive from RAF Kinloss, near Inverness to RAF Compton Basset near Calne in Wiltshire in the days before motorways, and as I remember a 19 hour journey- must have been mad to contemplate it, on a ‘Boiling Scott’, by this time the only thing wrong with it.
Having to go through every town en route it was embarrassing the amount of steam at traffic lights when I had to stop, but by this time I was used to it, the charm of Scott ownership. The cure – temporary, as it so happened – I used to carry numerous old glass lemonade bottles – no handy plastic containers in those days Gunga Din- filled with water carried in the sidecar boot. Water? Nae bother! I live in Scotland remember, re-filling the bottles up at burns, ditches, troughs and the odd garage when I refuelled. When the radiator boiled I filled up with water from the sidecar – sure slowed journey times down and required much perseverance. I’m gey thrane but!
So to the permanent cure, whilst in the Deep South, near Chippenham, lo and behold! I saw another Scott – only the second one I’d ever seen – and on examination I started to kick myself, for there staring me in the face was the answer, it was obvious, from the radiator header tank was a copper overflow pipe coming from just below the radiator cap internally to well below the engine water level externally. The ‘Boiling Scott’ only had a hole at the bottom of the header tank where the pipe should be and from which water flowed on refill, I thought this normal, silly, or should I say thicky me – aqueous thermal-convection currents did not exist!
Anyway, nothing that a bit of copper pipe and a 250watt soldering iron could not cure. Hurray! Being canny, I quickly got my money back on the empty lemonade bottles, which lightened the load on the ‘bike but curiously the return trip to Kinloss still took about 19 hours, it being uphill most of the way I suppose.
The Scott never boiled again!
Erik, I see from your picture that you have an overflow down pipe, but have you got a sufficient length of pipe inside the radiator to give a head of water in the header tank or perhaps, is it leaking due to corrosion say low down inside the tank dispelling enough water on warm up to lower the level to the extent that you do not have the thermal convection circuit so to speak and thus generate only steam. Just a thought.
Brian McDermott (Stooriefit)