10-12-2021, 12:53 AM
(This post was last modified: 10-12-2021, 01:03 AM by Bob Culver.)
To hark back to my near first post on this Forum, Raymond Mays (later of ERA and BRM fame) very successfully competed a 1.5 litre 100 mm stroke Bugatti Brescia post WW1. Amherst Villiers, later of supercharger note, assisted with the mods. Car had FN/Seven type b.e lube with pockets as Phoenix crank. They managed to get the car from 4,000 to 6,000 rpm but the bes then failed. They devised and fitted an extended scoops and then got to 6900 rpm, notably high at the time. In a book "The Man Who Supercharged Bond" (!) by Villiers. Personally I would have thought there was a risk of a trapped air cushion.The circular milled original Seven troughs seem less than ideal. But many cars have run distance with a blocked jet....
It would be interesting to see inside a running crankcase. I doubt if the exact alignment of the jets much matters!
My RP was fitted with an exchange engine at 40,000 miles but with apparentlyorigianl bes. At 100,000 miles signs of cracks but crankpins only about .001" wear (on very basic oils). The bes were refitted at evey frequent main bearing renewal and the regular new surface would have reduced wear.
It would be interesting to see inside a running crankcase. I doubt if the exact alignment of the jets much matters!
My RP was fitted with an exchange engine at 40,000 miles but with apparentlyorigianl bes. At 100,000 miles signs of cracks but crankpins only about .001" wear (on very basic oils). The bes were refitted at evey frequent main bearing renewal and the regular new surface would have reduced wear.