This is what I have on the "guts"
What else can I tell you about the bike? As displayed at the Deeley Museum, the
bike had not been ridden since the speed events at Rosamond and Bonneville dry
lakes. The speed attempt required two runs, the average of both being used. On
the first run, Gene recorded 151mph but cracked the oil feed pipe to the
rockers. This was repaired between runs. Second run, they also put some more
nitro in the tank but without any time to adjust the carburation as there was only
a minute left before the 30 minute interval had elapsed and they had to get the
bike back on the timed track. On the second run the bike was going very well
when at 150mph plus the bike seized. Gene pulled in the clutch and the bike
coasted over the finish line but still fast enough to beat the record Alzina gave
the 650 to Gene as a present.
I'd love to know more about what was inside the bike but can only make some
educated guesses based on what I know about BSA competition shop tuning
practice of the time. The first thing to know about this is that they didn't record
anything. Individuals may have kept their own private notes, but these haven't
survived anywhere that I know of. A more systematic approach to development
didn't happen until Roland Pike joined BSA later in 1951. The bike was based on
that ridden earlier by Fred Rist.
Fred Rist was one of BSA's star riders in the immediate post war period,
competing in every event the factory contested and was one of the team who
won the 1952 Maudes Trophy winning team. Fred only ever raced BSA
machinery. In the late 1940's Fred also competed in sand racing events at
Pendine and St. Andrews in Scotland and swept the board. Fred's impact on the
sport was due not just to his successes but also his dramatic riding style.
Laying the bike down on a footrest in a way similar to that of US dirt track racers
Fred would drive through corners in a controlled power slide at speeds of
140mph.One of the bikes Fred rode was an iron engined A10 fitted with twin TT
carburettors, high compression pistons and running on alcohol fuel and it's this
bike that was used as the blueprint for Gene's bike. I don't know which
mechanics actually built the bike but it's likely that it used a one-off camshaft
made by Jack Amott. Gene told me that he thinks that other than bigger valves,
a different cam, a bigger TT carburettor and dope fuel, everything else was
standard components built well.
I hope this gives you a little more information than you had and please send me
any more information you have.
Please let me know more about your bike and your plans to ride or race it on the
salt flats - I've be keen to add your story to my blog. After a long (!) sabbatical
it's time to update it a bit more regularly!
Best,
Myles, Glasgow