Eight straight pipes 2" x 48" is what I have on my Ardun. I copied the
factory racing pipes on the Vincent Black Lightning. They were usually
only 44" long, but I have an original factory set that are 48". The
cylinder size (500cc) was close to my Ardun, and the valve timing very
similar, so I figured, how could it be wrong? A factory Black Lightning
on 80-10-10 (methanol-petrol-benzole) took the World's Motorcycle Speed
Record with these pipes at 185 mph in New Zealand in 1955, running on a
two-lane public road closed for the occasion, the bike was privately
owned (Russell Wright) and ridden by the owner. This was the immortal
team of (Bob) Burns & Wright, as every Vincent man knows.
Having said all that, I know that the lore today is that four into one
makes more power on V-8s. But Willie Glass' Ardun that just set the
XXF/GR record at 159 at Maxton has eight short straight pipes (don't
know the diameter and length at the moment). Cheers, Bill
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