Pobjoy Probings
The two engines in question had been purchased 'post war' by a former RFC/RAF pilot who intended to put them in a Piper Cub, (That would have given a Cub some grunt) but no doubt the authorities would have scuppered that. The were both Niagra's as alluded one BTH and one Rotax, in crates, and complete less exhaust systems. The bottom crate had rotted so several of the cylinders were corroded. The BTH version therefore went in the Swift (and is still there) with the Rotax kept for spares. As for the R type indeed these were supplied with aluminium valve covers to keep dust out, but devoid of lubrication other than grease. All types had valves of low service life so were replaced with a modern material that is reliable. The other nuisance is the collector ring exhaust which would be fine (but expensive) in regular use so I substituted stubbs, and never had to change them. Remember I would do many hours in a display w-end so needed reliability. Great engine albeit (needs fettling) and watching of mag drives, but excellent power to weight ratio and thrust plus the afore mentioned FUN in operating such a fine piece of engine engineering. (a sooty face with white eyes) (behind the goggles) indicates a Pobjoy with stubbs), especially after a long flight. But the pilot will be smiling. PP