More on dynos from a little booklet I was searching for in my collection with test information ,1939, of Castrol's newly released oil...Castrolaero.....

When I did the recent post on engine testing with dynomometers I searched my archive for a little Castrol booklet I knew I had that featured motorcycles engines on test....
In fact the post of that dyno article had been delayed over a year because of that small booklet and finally in frustration I did the post without it....
Well I found it last night...ok where? Secured with catalogues of Lycett motorcycle seats of all things...any wonder I couldn't find it...
But it was worth waiting for and worth a post on its own.
In 1939 Castrol released a new engine oil..... Castrolaero.
They obviously arranged with quite a few major motorcycle manufacturers to test the product and give them a testimonial....
Some did prolonged road tests, most dyno tests...
I've scanned all the photos of the engines on test, a chart of their recommendations and only one testimonial, that from Velocette.
That said, the others were all positive...
Who were the manufacturers....?
AJS, Ariel,BSA,Excelsior,Levis,Matchless,Norton,O.K Supreme,Enfield,Scott,Sunbeam,Triumph and Velocette.
Left click on the illustrations to enlarge them...

Ariel engine under test...

BSA engine under test...

Excelsior Manxman engine under test...looks like Tyrell-Smith conducting it.

Two views of a Norton engine under test...

Sunbeam engine under test....

Tommy Mutton with a Velocette KTT Mk.7/8 engine under test...

Velocette testimonial letter to Castrol...

List of oil recommendations for various motorcycles....