classic motorcycle forum

I would be interested to gain current views on a digital speedometer/ odometer suitable for a Classic bike. Decent size, back light when needed, waterproof. I jumped in the deep end, so to say and bought one for £5, fine to 50 mph and then it records half speed. It may record half distance as well above 50, I only just fitted it, and done a overall slow run.
Its more the odometer I find useful on Vintage club runs, with route sheet giving, precise mileage’s. My chronometric clock is not bad, but not accurate enough and I don't think I am up to re-calibrating it. I also like to keep the chronometric odometer as a "fuel gauge

Hi, I got interested in a job lot of BTH magneto contavt breakers on ebay recently. I left things to the last minute and then had a re-read and noted they were for AG4 aircraft magnetos. They certainly look like those fitted to KC2 mag offen found on pre-unit Triumphs but I left myself with no time to ask question, so I backed off from bidding. Does anybody know if these are interchangeable ?

If you are really worried and ride short distances, you can alway do what this American Vincent owner does [extract form voc@jtan.com below]

"I make my own ethanol free gas
for use in small engines (chain saws etc which are particularly
effected by ethanol) and forstorage gas for larger ones. Just dump
about 20% water into the gas, agitate, let it sit a few days, then
drain out the water and ethanol mix (the ethanol combines with the
water in preference to the gas) which will have separated out and
gone to the bottom of the tank."

thanks guys. I think I should have elaborated my question.  It is the automatic devise [ADT]  in the timing cover, driving the magneto I was refering to as being dangerous and liable to fly apart, not the manual devise moving the cam ring. I have raced with BTH magnetos and have a high regard for them, but all my racing engines had fixed steel drive pinions and fixed cam rings.

thanks everybody, I thought it was just a slip ring change, but best to ask the experts first. I take the point about contact breaker and cam ring but this dosen't apply as I am robbing the armature only from a working clockwise mag to put in a non working anticlock mag

thanks guys.

no casting number anywhere that I can see

I assumed it was 6T  as it was lose on my 5T barrels. The head combustion chamber recess measures 2.845" and my 5T barrel spigot has an OD of 2.680". So I now assume the 1946 barrel must have wider spigots

So, this 1946 oil drain system, was a failed experiment? Its much more tidy, than the external pipes, perhaps the drillings were difficult? not enough meat in the barrel casting? I would be interested to learn more

I have a cast iron Triumph head, I believe 6T. It has recesses around the combustion chamber, so fits a spigotted barrel. However, the oil drain arrangements from the separate valve chambers are via drilling through to the joint face of the head to the barrel. The head has been cast with lugs that are normally drilled to take the oil drain via pipes to the pushrod tubes, but these have not been drilled ! unforunately I do not have a barrel with drilled oilways., was this a special casting or can the "normal" barrel be drilled?
I had a look at various parts lists and note that 6T barrel was spigotted in 1958 and flat in1960, but the books indicates that in both these years external drain pipes were used
so what year was it? and are there any decent books that catalogue detailed changes with early Triumphs?

Hi. I am told that early T110s ?1953/54 had iron heads. looking at my parts books for these years, I see that 6Ts had 4 main head fins and T110s had 5 fins, but it is not obvious if these are alloy or cast iron. I ask because I have a 650cc engine with T110 cases and a 4 fin cast iron head and would like to know if this is a missmatch or not.  Also am I correct in saying that the port diameters and valve sizes would be larger on the T110, compared to the 6T.