Castrol R
The recommended (by Castrol) way to get the smell of R - and it is instantly recognised - is to add a teaspoonful to every gallon of petrol. Curious: I never thought to hear my wife say "what's that lovely smell" for stuff that only costs £22 for 5 litres, not £122 for 5ml.
I run a Manx on R. It goes through the Norton motor three times (it has to be drained off after meetings or it sumps) then goes into a Rudge Ulster. I've been doing that for about 5 years now. The Rudge motor is clean inside and out, and doesn't sludge, form an irremovable varnish on the outside of the engine, or do any of the things old wife's tales tell you it will. (I suspect these were born when R was pure castor oil in the teens of the 20th century.) Any bike cleaner will shift it. I'd happily run it in the twin, but believe that SAE 40 oil is far too heavy for a motor that runs so cool. What R DOES do is create bright orange stains on any clothing with which it comes into contact, which resist certainly Persil Biological, but probably Persil Nuclear.
For information, the Manx box is run on ATF, and has been for nearly 15 years. Most actively raced Manxes are. ATF is about SAE 10. It works well in chaincases too.
I run Mobil1 0-30 there because it reduces sticking which the PV3 clutch (which is run fully wet after someone's chaincase mod) is prone to, left for a day or so. Once it has been freed off, it behaves perfectly. If anyone else with a fully wet PV3 clutch has found a solution for this problem, please advise. It's a minor irritation, but I'm curious.
