[Adrian II]

This one is a bit strange but has come up on ebay UK. I have also asked this on the MBR forum

So what's going on here? Basically a BTH competition magneto (AEI were the parent company by the early 1960s), but with a heavy-duty shielded HT lead and a strange armoured electrode thingy where we would normally expect to fit a spark plug. What the...?  What industrial or indeed military use could there be, realistically, for a racing mag? Some sort of furnace gas igniter?

As some of us have experience in the wider world outside of old bikes, I appeal to our experts for any little pearls of wisdom. Ebay item 333558305411 for anyone interested. Over to you guys.

Note that it's anti-clock rotation at the drive end, so ideal potential for a competition Bullet, if you fit a more conventional manual advance and HT lead. From the last picture it looks as though it might have been intended to revive Dr Frankenstein's pet rabbit. More power, Igor!

A.

[Bilgemaster]

That shielded and super robust HT lead and brass or bronze spark plug cap makes me think "aerospace", like a gas turbine ignitor system, as described here: https://www.flight-mechanic.com/turbine-engine-ignition-systems/

If memory serves, we do have a helicopter tech on this Forum, so with a bit of luck he may swing on by for comment. I might also try contacting the seller concerning its provenance.

That seems like a great find, Adrian, but if it turns out to be some surplus military spec spark box, and you screw it onto some Bullet, you'll really need to then paint that thing "battle green" like mine, or at least a tasteful khaki.

By the way, here's a direct link to that eBay UK auction for the ready reference of those in other lands: https://www.ebay.co.uk/itm/NEW-OLD-STOCK-AEI-BTH-SKH1-MAGNETO-HUGE-SPARK-SUIT-JAP-SPEEDWAY-ENGINE-VINTAGE/333558305411?hash=item4da99fd283

[Adrian II]

Ah yes, I found that gas turbine page too. Given that the thing is probably a good sixty years old what ever it was meant for has probably long since ceased flying. For Bullet use it would be better on a set of Redditch crankcases which still have the mag platform cast in, otherwise you'd have to copy what young Andreas has been doing for the Laubfrosch. The rotation is correct!

While we are on about rare meat BTH mags, feast your eyes on this little fellow which has been posted on ebay UK, yes this week's unicorn is:





A BKH1-TT racing mag. You may drool. Now if only I'd waited a few months I could have had a pukka racing mag for A Proj Too Far for less than the cost of buying the fixer-upper KC1 and getting it fixed up. Never mind, someone out there must need it for a Velocette scrambler or racer.

https://www.ebay.co.uk/itm/BTH-TT-MAGNETO-VELOCETTE-VINCENT/324117378103

A.

[Bilgemaster]

Yup! For magneto fanciers I imagine that TT rig's utterly droolworthy. I've never had one on any of my old junkers, though I understand earlier years of my Norton N15CS used them. I do recall that by far the busiest vendor at the Triumph National Rally I attended in Oley, Pennsylvania a couple of years back was a guy who specialized in just magneto rebuilds. For pretty much all three days of the event he had a long queue of folks cradling armfuls of tired spark boxes, often stretching all the way back to the snack bar. I doubt the poor shnook ever had a chance to have a look around. So there's your trade with a bright outlook, kiddies: specialize in rehabbing moribund or obsolete vehicle components...maybe run a sideline repairing and oiling buggy whips! You'll be busier than [insert folksy saying here].

[Adrian II]

Only thing wrong with the TT mag above is that is has somehow picked up the non-competition type points/end bearing housing. Were I foolish enough in these perilous times to hit 500GBP's worth of Buy it Now button, I do happen to have a choice of parts to put that right. Some of these things do sit around for many months before someone buys them, though...

A.

[Adrian II]

Meanwhile opinion of the MBR forum also seems to confirm it was for igniting jet engines, on possibly one of the RAF's cold war warriors.

Maybe one of these?

https://www.youtube.com/watch?v=ftt2q6zNQ1g

Or these?

https://www.youtube.com/watch?v=jXLBhBz_2tE

or one of these?

https://www.youtube.com/watch?v=Bb5puGAx0ec

A.

[heloego]

Another one of my recently rare visits here.Now that I'm retired I have more time for the mods on my buddies bike and this forum!
A bit of a late-comer to this thread, but yes that is definitely an early ignitor for a turbine engine, most likely for the early can annular styles fitted to the '50s jets and to early axial styles until a solid state ignitor box was developed. These same boxes were also used on the later higher power 18-cylinder twin radials as used in the Thunderbolt, Corsair, Constellation, and others.The charge can kill you. Quick.

Before the solid state boxes were designed and deemed airworthy those older high tension boxes were often mounted one for each ignitor used on the turbines. We had a couple examples back when I was in school.

The current solid state high tension boxes can handle multiple ingnitors.

[Adrian II]

The igniter mag sold for a little over £200, I suspect it will end up on a classic motorcycle with a conventional HT lead and plug.

You can probably guess where the other racing magneto ended up...

A.